[Federal Register Volume 79, Number 168 (Friday, August 29, 2014)]
[Rules and Regulations]
[Pages 51657-51710]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-20059]
[[Page 51657]]
Vol. 79
Friday,
No. 168
August 29, 2014
Part II
Department of the Interior
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Fish and Wildlife Service
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50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Threatened Status for
Oregon Spotted Frog; Final Rule
Federal Register / Vol. 79 , No. 168 / Friday, August 29, 2014 /
Rules and Regulations
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R1-ES-2013-0013; 4500030113]
RIN 1018-AZ04
Endangered and Threatened Wildlife and Plants; Threatened Status
for Oregon Spotted Frog
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine
threatened species status under the Endangered Species Act of 1973
(Act), as amended, for Oregon spotted frog (Rana pretiosa), an
amphibian species from British Columbia, Washington, Oregon, and
California. The effect of this regulation will be to add this species
to the List of Endangered and Threatened Wildlife.
DATES: This rule is effective September 29, 2014.
ADDRESSES: This final rule is available on the Internet at http://www.regulations.gov and http://www.fws.gov/wafwo/osf.html. Comments and
materials we received, as well as some of the supporting documentation
we used in preparing this rule, are available for public inspection at
http://www.regulations.gov. All of the comments, materials, and
documentation that we considered in this rulemaking are available by
appointment, during normal business hours at: U.S. Fish and Wildlife
Service, Washington Fish and Wildlife Office, 510 Desmond Drive SE.,
Suite 102, Lacey, WA 98503; by telephone at 360-753-9440; or by
facsimile at 360-753-9445.
FOR FURTHER INFORMATION CONTACT: Ken Berg, Manager, U.S. Fish and
Wildlife Service, Washington Fish and Wildlife Office, 510 Desmond
Drive SE., Suite 102, Lacey, WA 98503; telephone 360-753-9440;
facsimile 360-753-9445. Persons who use a telecommunications device for
the deaf (TDD) may call the Federal Information Relay Service (FIRS) at
800-877-8339.
SUPPLEMENTARY INFORMATION:
Executive Summary
Why we need to publish a rule. Under the Endangered Species Act, a
species may warrant protection through listing if it is endangered or
threatened throughout all or a significant portion of its range.
Listing a species as an endangered or threatened species can only be
completed by issuing a rule.
This rule will finalize the listing of the Oregon spotted frog
(Rana pretiosa) as a threatened species.
The basis for our action. Under the Endangered Species Act, we can
determine that a species is an endangered or threatened species based
on any of five factors: (A) The present or threatened destruction,
modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence. We have determined that the Oregon
spotted frog is impacted by one or more of the following factors:
Habitat necessary to support all life stages continues to
be impacted or destroyed by human activities that result in the loss of
wetlands to land conversions; hydrologic changes resulting from
operation of existing water diversions/manipulation structures, new and
existing residential and road developments, drought, and removal of
beavers; changes in water temperature and vegetation structure
resulting from reed canarygrass invasions, plant succession, and
restoration plantings; and increased sedimentation, increased water
temperatures, reduced water quality, and vegetation changes resulting
from the timing and intensity of livestock grazing (or in some
instances, removal of livestock grazing at locations where it maintains
early seral stage habitat essential for breeding).
Predation by nonnative species, including nonnative trout
and bullfrogs.
Inadequate existing regulatory mechanisms that result in
significant negative impacts, such as habitat loss and modification.
Other natural or manmade factors including small and
isolated breeding locations, low connectivity, low genetic diversity
within occupied sub-basins, and genetic differentiation between sub-
basins.
Peer review and public comment. We sought comments from independent
specialists to ensure that our designation is based on scientifically
sound data, assumptions, and analyses. We invited these peer reviewers
to comment on our listing proposal. We also considered all comments and
information we received during the comment period.
Previous Federal Actions
On August 29, 2013, we published a proposed rule (78 FR 53582) to
list the Oregon spotted frog as a threatened species under the Act (16
U.S.C. 1531 et seq.). Please refer to that proposed rule for a detailed
description of Federal actions concerning this species. Also on August
29, 2013, we proposed to designate critical habitat for the Oregon
spotted frog (78 FR 53538). On September 26, 2013, we published a
document (78 FR 59334) extending the comment period of both proposed
rules and announcing a public hearing on the proposals to list and
designate critical habitat for this species.
This rule concerns only the listing of the Oregon spotted frog; we
will make a final determination concerning critical habitat for the
Oregon spotted frog in the near future.
Background
The Oregon spotted frog is named for the characteristic black spots
covering the head, back, sides, and legs. The dark spots have ragged
edges and light centers, usually associated with a tubercle or raised
area of skin. The coloration patterns on Oregon spotted frogs all
develop with age; the spots become larger and darker and the edges
become more ragged as the individual gets older (Hayes 1994, p. 14).
Overall body color also varies with age. Juveniles are usually brown
or, occasionally, olive green on the back and white, cream, or flesh-
colored with reddish pigments on the underlegs and abdomen developing
with age (McAllister and Leonard 1997, pp. 1-2). Adults range from
brown to reddish brown but tend to become redder with age. Large,
presumably older, individuals may be brick red over most of the dorsal
(back) surfaces (McAllister and Leonard 1997, pp. 1-2). Red surface
pigments on the adult abdomen also expand with age, and the underlegs
of adults become a vivid orange red. Tan to orange folds along the
sides of the back (dorsolateral folds) extend from behind the eye to
midway along the back (McAllister and Leonard 1997, p. 1). The eyes are
upturned; there is a faint mask, and a light jaw stripe extends to the
shoulder. Small bumps and tubercles usually cover the back and sides
(Leonard et al. 1993, p. 130). The hind legs are short relative to body
length, and the hind feet are fully webbed (Leonard et al. 1993, p.
130).
The Oregon spotted frog is a medium-sized frog that ranges from
about 1.7 to 4.1 inches (in) (44 to 105 millimeters (mm)) in body
length (McAllister and Leonard 1997, p. 1; Rombough et al.
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2006, p. 210). Females are typically larger than males; females reach
up to 105 mm (4 in) (Rombough et al. 2006, p. 210) and males to 75 mm
(3 in) (Leonard et al. 1993, p. 130).
Morphological characters can be used to distinguish Oregon spotted
frogs from other closely related spotted frogs. Mottling with dark
pigments and fragmentation of the superficial red or orange-red wash on
the abdomen can distinguish the Oregon spotted frog from some Columbia
spotted frog populations (Hayes 1997, p. 3; Hayes et al. 1997, p. 1).
Other characteristics, such as coloration of the underlegs and abdomen,
size and shapes of spots, groin mottling, eye positions, relative
length of hind legs to body size, degree of webbing, and behaviors can
be used to distinguish Oregon spotted frogs from adults of closely
related species. Tadpoles are more difficult to differentiate from
other species (Corkran and Thoms 1996, p. 150; McAllister and Leonard
1997, p. 6).
The Oregon spotted frog has a weak call consisting of a rapid
series of six to nine low clucking notes described as sounding like a
distant woodpecker's tapping. Males will call at any time, both day and
night (McAllister and Leonard 1997, p. 12). Males have been documented
to call from submerged sites that are physically distant (tens to
hundreds of meters) from oviposition (egg-laying) sites (Bowerman 2010,
p. 85). These submerged calls are inaudible at the surface and begin
several days prior to breeding. Submerged calling is more frequent at
night, although daytime calling has been recorded during overcast days
(Bowerman 2010, pp. 85-86). It is unclear if mate selection takes place
during this period of calling remotely from the breeding site, but it
seems likely (Bowerman 2010, p. 86). This species rarely vocalizes
except during the breeding season (Leonard et al. 1993, p. 132);
however, vocalizations have been heard during the fall (Leonard et al.
1997, pp. 73-74; Pearl 2010, pers. comm.).
Taxonomy
The scientific name Rana pretiosa (order Anura; family Ranidae) was
first applied to a series of five specimens collected in 1841 from the
vicinity of Puget Sound (Baird and Girard 1853, p. 378). Two of these
specimens were later determined to be northern red-legged frogs (Rana
aurora) (Hayes 1994, p. 4; Green et al. 1997, p. 4). Dunlap (1955)
demonstrated the morphological differences between northern red-legged
frogs, Cascades frogs, and spotted frogs. Subsequently, the ``spotted
frog'' was separated into two species, Rana pretiosa (Oregon spotted
frog) and Rana luteiventris (Columbia spotted frog) based on genetic
analyses (Green et al. 1996, 1997).
In 2008, phylogenetic analyses were conducted on samples of Oregon
spotted frogs collected from 3 locations in Washington and 13 locations
in Oregon (Funk et al. 2008). Results indicate two well-supported
clades (a group of biological taxa (as species) that includes all
descendants of one common ancestor) nested within the Oregon spotted
frog: The Columbia clade (Trout Lake Natural Area Preserve (NAP) and
Camas Prairie) and the southern Oregon clade (Wood River and Buck Lake
in the Klamath Basin). The two sites that comprise the Columbia clade
occur on opposite sides of the Columbia River in Washington (Trout Lake
NAP) and in Oregon (Camas Prairie). Haplotype and nucleotide diversity
was low for Oregon spotted frogs in general and was very low for each
of the two nested clades, respectively (Funk et al. 2008, p. 203). Only
six haplotypes were found across the entire range of the Oregon spotted
frog, indicating low genetic variation (Funk et al. 2008, p. 205).
Recent genetic work conducted by Robertson and Funk (2012, p. 6) in the
Deschutes and Klamath basins indicate the sampled Oregon spotted frog
sites are characterized by very small effective population sizes and
little genetic variation (i.e., measured as low heterozygosity and low
allelic richness).
Blouin et al. (2010) performed genetic analyses on Oregon spotted
frogs from 23 of the known sites in British Columbia, Washington, and
Oregon for variation at 13 microsatellite loci and 298 base pairs of
mitochondrial DNA. Their results indicate that Rana pretiosa comprised
six major genetic groups: (1) British Columbia; (2) the Chehalis
drainage in Washington, (3) the Columbia drainage in Washington, (4)
Camas Prairie in northern Oregon, (5) the central Cascades of Oregon,
and (6) the Klamath basin (Blouin et al. 2010, pp. 2184-2185). Within
the northern genetic groups, the British Columbia (Lower Fraser River)
and Chehalis (Black River) populations form the next natural grouping
(Blouin et al. 2010, p. 2189). Recently discovered locales in the
Sumas, South Fork Nooksack, and Samish Rivers occur in-between these
two groups. While no genetic testing has been done on these newly found
populations, it is reasonable to assume that they are likely to be
closely related to either the British Columbia or Chehalis group, or
both, given their proximity and use of similar lowland marsh habitats.
Levels of genetic variation in the Oregon spotted frog groups are
low compared to other ranid frogs, suggesting these populations are
very small and/or very isolated (Blouin et al. 2010, p. 2184). Blouin
et al. (2010) found a high frequency of private alleles in the
mitochondrial DNA (i.e., an allele found in only one population or
geographic location) in the central Cascades and Klamath Basin groups.
This finding suggests an historical (rather than recent) isolation
between individual groups (Blouin et al. 2010, p. 2189). This finding
also reinforces microsatellite-based conclusions that gene flow among
sites has been very low, even on small geographic scales (Blouin et al.
2010, p. 2188). Recent work by Robertson and Funk (2012) in the
Deschutes and Klamath basins reinforces the Blouin et al. (2010)
findings. Due to Oregon spotted frogs' highly aquatic habits,
connectivity between Oregon spotted frog sites depends on the
connectivity of streams, rivers, and lakes. Gene flow (based on both
microsatellite and mitochondrial analyses) is extremely low beyond 6
miles (mi) (10 kilometers (km)) (Blouin et al. 2010, pp. 2186, 2188),
and most Oregon spotted frog populations are separated by more than 6.2
mi (10 km). Therefore, Blouin et al. (2010, p. 2189) and Robertson and
Funk (2012, p. 5) hypothesize that low aquatic connectivity and small
isolated populations are important causes of the low genetic diversity
within sites and the high genetic differentiation among sites.
Life History
Male Oregon spotted frogs are not territorial and often gather in
large groups of 25 or more individuals at specific locations (Leonard
et al. 1993, p. 132). Breeding occurs in February or March at lower
elevations and between early April and early June at higher elevations
(Leonard et al. 1993, p. 132). Males and females separate soon after
egg-laying, with females returning to fairly solitary lives. Males
often stay at the breeding site, possibly for several weeks, until egg-
laying is completed (McAllister and Leonard 1997, p. 13). (The terms
``egg-laying site'' or ``egg-laying habitat'' are used interchangeably
with ``breeding site,'' ``breeding area,'' or ``breeding habitat''
throughout this rule). Breeding site, breeding area, and breeding
location terminology refer to geographic areas where concentrated
breeding has been observed.
Oregon spotted frogs' eggs are extremely vulnerable to desiccation
and
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freezing as a result of the species' laying habits. Females may deposit
their egg masses at the same locations in successive years, indicating
the sites may have unique characteristics. For example, some marked
males and females at Sunriver (Upper Deschutes River, Oregon) returned
to the same breeding site for 3 or more years (Bowerman 2006, pers.
comm.). Further, at several sites in Oregon and Washington, the same
egg-laying locations have been used for more than a decade (Hayes 2008,
pers. comm.; Hallock 2012, pp. 24-27). Although egg masses are
occasionally laid singly, the majority of egg masses are laid
communally in groups of a few to several hundred (Licht 1971, p. 119;
Nussbaum et al. 1983, p. 186; Cook 1984, p. 87; Hayes et al. 1997 p. 3;
Engler and Friesz 1998, p. 3). They are laid in shallow, often
temporary, pools of water; on gradually receding shorelines; on benches
of seasonal lakes and marshes; and in wet meadows. These sites are
usually associated with the previous year's emergent vegetation and are
generally no more than 14 in. (35 centimeters (cm.)) deep (Pearl and
Hayes 2004, pp. 19-20). Most of these sites dry up later in the season
(Engler 1999, pers. comm.), but are connected via surface water to
permanently wetted areas, such as creeks, wetlands, and springs.
Shallow water is easily warmed by the sun, and warmth hastens egg
development (McAllister and Leonard 1997, p. 8). However, laying eggs
in shallow water can result in high mortality rates for eggs and
hatchling larvae due to desiccation or freezing.
Licht (1974, pp. 617-625) documented the highly variable mortality
rates for spotted frog life-history stages in marsh areas in the lower
Fraser Valley, British Columbia, embryos (30 percent), tadpoles (99
percent), and post-metamorphic (after the change from tadpole to adult,
or ``metamorphosis'') frogs (95 percent). Licht (1974, p. 625)
estimated mortality of each life stage and predicted only a 1 percent
chance of survival of eggs to metamorphosis, a 67 percent chance of
juvenile survival for the first year, and a 64 percent adult annual
survival with males having a higher mortality rate than females. An
average adult between-year survival of 37 percent was estimated by a
mark-recapture study at Dempsey Creek in Washington between 1997 and
1999 (Watson et al. 2000, p. 19).
Adult Oregon spotted frogs begin to breed by 1 to 3 years of age,
depending on sex, elevation, and latitude. Males may breed at 1 year at
lower elevations and latitudes but generally breed at 2 years of age.
Females breed by 2 or 3 years of age, depending on elevation and
latitude. Longevity of the species is not well understood; however,
there are multiple examples of Oregon spotted frogs living beyond 7
years of age (Watson et al. 2000, p. 21; McAllister 2008, pers. comm.;
Oertley 2005, pers. comm.; Pearl 2005, pers. comm.).
Egg-laying can begin as early as February in lowland areas of
British Columbia and Washington and as late as early June in the higher
elevations. Tadpoles metamorphose into froglets (tiny frogs) (about
0.6-1.75 in. (16-43 mm.) in length) during their first summer (Leonard
et al. 1993, p. 132; Pearl and Bowerman 2005, pers. comm.). Tadpoles
are grazers, having rough tooth rows for scraping plant surfaces and
ingesting plant tissue and bacteria. They also consume algae, detritus,
and probably carrion (Licht 1974, p. 624; McAllister and Leonard 1997,
p. 13).
Post-metamorphic Oregon spotted frogs are opportunistic predators
that prey on live animals, primarily insects, found in or near the
water. Prey groups of adult frogs include leaf beetles (Chrysomelidae),
ground beetles (Carabidae), spiders (Arachnida), rove beetles
(Staphylinidae), syrphid flies (Syrphidae), long-legged flies
(Dolichopodidae), ants (Formicidae), water striders (Gerridae),
spittlebugs (Cercopidae), leaf hoppers (Cicadellidae), aphids
(Aphididae), dragonflies and damsel flies (Odonates), and yellowjackets
(Vespidae) (Licht 1986a, pp. 27-28). Oregon spotted frogs also eat
adult Pacific tree frogs (Pseudacris regilla), small red-legged frogs,
and newly metamorphosed red-legged frogs and western toad (Anaxyrus
boreas) juveniles (Licht 1986a, p. 28; Pearl and Hayes 2002, pp. 145-
147; Pearl et al. 2005a, p. 37).
Similar to many North American pond-breeding anurans (belonging to
the Order Anura, which contains all frogs), predators can strongly
affect the abundance of larval and post-metamorphic Oregon spotted
frogs. The heaviest losses to predation are thought to occur shortly
after tadpoles emerge from eggs, when they are relatively exposed and
poor swimmers (Licht 1974, p. 624). However, the odds of survival
appear to increase as tadpoles grow in size and aquatic vegetation
matures, thus affording cover (Licht 1974, p. 624). Adult Oregon
spotted frogs have a number of documented and potential natural
predators, including garter snakes (Thamnophis species (spp.)), great
blue herons (Ardea herodias), green herons (Butorides virescens),
American bitterns (Botaurus lentiginosus), belted kingfishers (Ceryle
alcyon), sandhill cranes (Grus canadensis), raccoons (Procyon lotor),
coyotes (Canis latrans), striped skunks (Mephitis mephitis), mink
(Neovison vison), river otters (Lontra canadensis), and feral cats
(Felis domesticus) (McAllister and Leonard 1997, p. 13; Hayes et al.
2005, p. 307; Hayes et al. 2006, p. 209). Tadpoles may be preyed upon
by numerous vertebrate predators including belted kingfishers, hooded
mergansers (Lophodytes cucullatus), common garter snakes (Thamnophis
sirtalis), western terrestrial garter snakes (Thamnophis elegans),
larval and adult roughskin newts (Taricha granulosa), larval
northwestern salamanders (Ambystoma gracile), cutthroat trout
(Oncorhynchus clarki), Olympic mudminnows (Novumbra hubbsi), and three-
spined sticklebacks (Gasterosteus aculeatus) (McAllister and Leonard
1997, p. 14).
Subadult Oregon spotted frogs have been observed within dense
aggregations of recently hatched Oregon spotted frog tadpoles, and
stomach flushing verified that these subadult Oregon spotted frogs had
consumed (cannibalized) recently hatched conspecific (belonging to the
same species) tadpoles (McAllister 2008, pers. comm.). Invertebrate
predators include dytiscid beetles (Dytiscus spp.), giant water bugs
(Lethocerus americanus), backswimmers (Notonecta undulata and N.
kirbyi), water scorpions (Ranatra sp.), dragonfly nymphs (Odonata), and
worm-leeches (Arhynchobdellida) (McAllister and Leonard 1997, p. 14).
Leeches and other invertebrates, roughskin newts, and northwestern
salamanders are likely Oregon spotted frog egg predators (Licht 1974,
p. 622).
The introduction of nonnative species into the historical range of
the Oregon spotted frog is believed to have contributed to the decline
of this and other species of frogs (Hayes and Jennings 1986, pp. 491-
492, 494-496; Hayes 1994, p. 5; 61 FR 25813; McAllister and Leonard
1997, pp. 25-26; Pearl et al. 2004, pp. 17-18). American bullfrogs
(Lithobates catesbeianus) are known predators of Oregon spotted frogs
(R. Haycock and R.A. Woods, unpubl. data, 2001 cited in COSFRT 2012, p.
19), and introduced fish such as brook trout (Salvelinus fontinalis)
and centrarchids (Micropterus and Lepomis spp.) are also likely
predators (Pearl et al. 2009a, p. 140).
Habitat
Watson et al. (2003, p. 298) summarized the conditions required for
completion of the Oregon spotted frog's
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life cycle as shallow water areas for egg and tadpole survival;
perennially deep, moderately vegetated pools for adult and juvenile
survival in the dry season; and perennial water for protecting all age
classes during cold wet weather.
The Oregon spotted frog inhabits emergent wetland habitats in
forested landscapes, although it is not typically found under forest
canopy. Historically, this species was also associated with lakes in
the prairie landscape of the Puget lowlands (McAllister and Leonard
1997, p. 16). This is the most aquatic native frog species in the
Pacific Northwest (PNW), as all other species have a terrestrial life
stage. It is found in or near a perennial body of water, such as a
spring, pond, lake, sluggish stream, irrigation canal, or roadside
ditch (Engler 1999, pers. comm.). The observation that extant Oregon
spotted frog populations tend to occur in larger wetlands led Hayes
(1994, Part II pp. 5, 7) to hypothesize that a minimum size of 9 acres
(ac) (4 hectares (ha)) may be necessary to reach suitably warm
temperatures and support a large enough population to persist despite
high predation rates. However, Oregon spotted frogs also occupy smaller
sites and are known to occur at sites as small as 2.5 ac (1 ha) and as
large as 4,915 ac (1,989 ha) (Pearl and Hayes 2004, p. 11). Oregon
spotted frogs have been found at elevations ranging from near sea level
in the Puget Trough lowlands in Washington to approximately 5,000 feet
(ft) (1,500 meters (m)) in the Oregon Cascades in western Oregon
(Dunlap 1955, p. 316; Hayes 1997, p. 16; McAllister and Leonard 1997,
pp. 8-10).
Oregon spotted frogs can make use of a variety of pond types as
long as there is sufficient vegetation and seasonal habitat available
for egg-laying, tadpole rearing, summer feeding, and overwintering
(Pearl et. al. 2009a, p. 144). Oregon spotted frogs at Dempsey Creek in
Washington selected areas of relatively shallow water with less
emergent vegetation but more submergent vegetation than adjacent
habitats. They avoided dry, upland areas of pasture grass (Watson et
al. 1998, p. 10; 2000, pp. 54-57; 2003, p. 297). Radio telemetry data
indicate Oregon spotted frogs at Dempsey Creek also make extensive use
of scrub-shrub wetland habitats adjacent to forested uplands during the
winter (moving between the creek and egg-laying areas) (Risenhoover et
al. 2001a, p. 13).
Oregon spotted frogs breed in shallow pools (<=14 in (35 cm) deep)
that are near flowing water, or which are connected to larger bodies of
water during seasonally high water or at flood stage. Characteristic
vegetation includes grasses, sedges, and rushes, although eggs are laid
where the vegetation is low or sparse, such that vegetation structure
does not shade the eggs (McAllister and Leonard 1997, p. 17). While
native vegetation is the preferred substrate, the frog also uses short,
manipulated, reed canarygrass/native vegetation mix (Engler 1999, pers.
comm.). Full solar exposure seems to be a significant factor in egg-
laying habitat selection (McAllister and White 2001, p. 12; Pearl and
Hayes 2004, p. 18). The availability of the unique characteristics of
traditional egg-laying sites is limited, and adults may have limited
flexibility to switch sites (Hayes 1994, p. 19). This may make the
Oregon spotted frog particularly vulnerable to modification of egg-
laying sites (Hayes 1994, p. 19).
After breeding, during the dry season, Oregon spotted frogs move to
deeper, permanent pools or creeks (Watson et al. 2003, p. 295). They
are often observed near the water's surface basking and feeding in beds
of floating and submerged vegetation (Watson et al. 2003, pp. 292-298;
Pearl et al. 2005a, pp. 36-37).
Known overwintering sites are associated with flowing systems, such
as springs and creeks, that provide well-oxygenated water (Hallock and
Pearson 2001, p. 15; Hayes et al. 2001, pp. 20-23; Tattersall and
Ultsch 2008, pp. 123, 129, 136) and sheltering locations protected from
predators and freezing (Risenhoover et al. 2001b; Watson et al. 2003,
p. 295). Oregon spotted frogs apparently burrow in mud, silty
substrate; clumps of emergent vegetation; woody accumulations within
the creek; and holes in creek banks when inactive during periods of
prolonged or severe cold (Watson et al. 2003, p. 295; Hallock and
Pearson 2001, p. 16; McAllister and Leonard 1997, p. 17). They are,
however, intolerant of anoxic (absence of dissolved oxygen) conditions
and are unlikely to burrow into the mud for more than a day or two
(Tattersall and Ultsch 2008, p. 136) because survival under anoxic
conditions is only a matter of 4 to 7 days (Tattersall and Ultsch 2008,
p. 126). This species remains active during the winter and selects
microhabitats that can support aerobic metabolism and minimize exposure
to predators (Hallock and Pearson 2001, p. 15; Hayes et al. 2001, pp.
20-23; Tattersall and Ultsch 2008, p. 136). In central Oregon, where
winters generally result in ice cover over ponds, Oregon spotted frogs
follow a fairly reliable routine of considerable activity and movement
beneath the ice during the first month following freeze-up. Little
movement is observed under the ice in January and February, but
activity steadily increases in mid-March, even when ice cover persists
(Bowerman 2006, pers. comm.). Radio-tracked frogs remained active all
winter, even under the ice at Trout Lake NAP (Hallock and Pearson 2001,
pp. 12, 14, 15) and Conboy Lake National Wildlife Refuge (NWR) (Hayes
et al. 2001, pp. 16-19).
Results of a habitat utilization and movement study at Dempsey
Creek in Washington indicate that adult frogs made infrequent movements
between widely separated pools and more frequent movements between
pools in closer proximity (Watson et al. 2003, p. 294), but remained
within the study area throughout the year. Home ranges averaged 5.4 ac
(2.2 ha), and daily movement was 16-23 ft (5-7 m) throughout the year
(Watson et al. 2003, p. 295). During the breeding season (February-
May), frogs used about half the area used during the rest of the year.
During the dry season (June-August), frogs moved to deeper, permanent
pools, and occupied the smallest range of any season, then moved back
toward their former breeding range during the wet season (September-
January) (Watson et al. 2003, p. 295). Individuals equipped with radio
transmitters stayed within 2,600 ft (800 m) of capture locations at the
Dempsey Creek site (Watson et al. 1998, p. 10) and within about 1,312
ft (400 m) at the Trout Lake NAP (Hallock and Pearson 2001, p. 16).
Recaptures of Oregon spotted frogs at breeding locations in the
Buck Lake population in Oregon indicated that adults often move less
than 300 ft (100 m) between years (Hayes 1998a, p. 9). However, longer
travel distances, while infrequent, have been observed between years
and within a single year between seasons. Three adult Oregon spotted
frogs (one male and two females) marked in a study at Dempsey Creek and
the Black River in Washington moved a distance of 1.5 mi (2.4 km)
between seasons along lower Dempsey Creek to the creek's mouth from the
point where they were marked (McAllister and Walker 2003, p. 6). An
adult female Oregon spotted frog traveled 1,434 ft (437 m) between
seasons from its original capture location at the Trout Lake Wetland
NAP (Hallock and Pearson 2001, p. 8). Two juvenile frogs at the Jack
Creek site in Oregon were recaptured the next summer 4,084 ft (1,245 m)
and 4,511 ft (1,375 m) downstream from where they were initially
marked, and one adult female moved 9,183 ft (2,799 m) downstream
(Cushman and Pearl 2007, p. 13). Oregon spotted frogs at the Sunriver
site routinely make annual migrations of 1,640 to 4,265 ft (500 to
[[Page 51662]]
1,300 m) between the major breeding complex and an overwintering site
(Bowerman 2006, pers. comm.).
While these movement studies are specific to Oregon spotted frogs,
the number of studies and size of the study areas are limited and have
not been conducted over multiple seasons or years. In addition, the
ability to detect frogs is challenging because of the difficult terrain
and the need for the receiver and transmitter to be in close proximity.
Hammerson (2005) recommends that a 3.1-mile (5-km) dispersal distance
be applied to all ranid frog species, because the movement data for
ranids are consistent. The preponderance of data indicates that a
separation distance of several kilometers may be appropriate and
practical for delineation of occupancy, despite occasional movements
that are longer or that may allow some genetic interchange between
distant populations (for example, the 6.2-mi (10-km) distance noted by
Blouin et al. 2010, pp. 2186, 2188). Accordingly, based on the best
available scientific information, we presume that Oregon spotted frog
habitats are connected for purposes of genetic exchange when occupied/
suitable habitats fall within a maximum movement distance of 3.1 mi (5
km).
Historical Range/Distribution
Historically, the Oregon spotted frog ranged from British Columbia
to the Pit River basin in northeastern California (Hayes 1997, p. 40;
McAllister and Leonard 1997, p. 7). Oregon spotted frogs have been
documented at 61 historical localities in 48 watersheds (3 in British
Columbia, 13 in Washington, 29 in Oregon, and 3 in California) in 31
sub-basins (McAllister et al. 1993, pp. 11-12; Hayes 1997, p. 41;
McAllister and Leonard 1997, pp. 18-20; COSEWIC 2011, pp. 12-13) (see
Table 1). We are assuming the watersheds that have recently been
documented to be occupied were also occupied historically based on
their complete disconnect from known-occupied watersheds and the
limited dispersal ability of the Oregon spotted frog. In our analysis
of the status and threats to the Oregon spotted frog, we first assessed
conditions by breeding location and occupied watersheds, and then
summarized the conditions by occupied sub-basin (see Summary of Factors
Affecting the Species for more information). Our Threats Synthesis
Rangewide Analysis, which includes this finer scale analysis of
distribution, is available at http://www.regulations.gov and http://www.fws.gov/wafwo. However, for the rest of the document, we will
describe historical and current range or distribution based on river
sub-basins/watersheds. A river sub-basin is equivalent to a 4th field
watershed and a hydrologic unit code (HUC) of 8. A watershed is
equivalent to a 5th field watershed and a HUC 10.
Table 1--Oregon Spotted Frog Historical and Extant Distribution
Throughout Range
------------------------------------------------------------------------
Location Sub-basins*: Watersheds
------------------------------------------------------------------------
British Columbia......................... Lower Fraser River
sub-basin near Sumas Prairie
in Abbotsford, Nicomen
Island in Matsqui, and in
Langley Township. Recently
(1996/1997 and 2008)
discovered at MD Aldergrove,
Maria Slough, Mountain
Slough, and Morris Valley
Washington Counties: Clark, King, Fraser River sub-
Klickitat, Pierce, Skagit, Snohomish, basin: Recently discovered
Thurston, and Whatcom. (2012) in the Sumas River, a
tributary to the Lower
Chilliwack River watershed;
Nooksack River sub-
basin: South Fork Nooksack
River (recently discovered
(2011 and 2012) in the Black
Slough);
Straits of Georgia
sub-basin: Recently
discovered (2011 and 2012)
along the mainstem of the
Samish River;
Lower Skagit River
sub-basin: Skagit River-
Frontal Skagit Bay and
Finney Creek-Skagit River;
Skykomish River sub-
basin: Woods Creek-Skykomish
River at Monroe;
Duwamish River sub-
basin: Lower Green River at
Kent;
Lake Washington sub-
basin: Lake Washington at
Seattle;
Puget Sound (no sub-
basin): Chambers Creek-
Frontal Puget Sound
(Spanaway Lake) and McLane
Creek-Frontal Puget Sound
(Patterson/Pattison Lake);
Nisqually River sub-
basin: Lower Nisqually River-
Frontal Puget Sound
(Kapowsin);
Upper Chehalis River
sub-basin: Black River
(Dempsey Creek, Beaver
Creek, Blooms Ditch, and
recently discovered in
Salmon and Fish Pond
Creeks);
Lower Willamette
River sub-basin: Salmon
Creek-Frontal Columbia River
at Brush Prairie, Vancouver,
and possibly Burnt Bridge
Creek at Orchards;
Middle Columbia-Hood
River sub-basin: White
Salmon River (Trout Lake
Creek at Gular and Trout
Lake);
Klickitat River sub-
basin: Middle Klickitat
River (Conboy Lake on
Outlet, Frazier, and Chapman
Creeks)
Oregon Counties: Multnomah, Clackamas, Lower Willamette
Marion, Linn, Benton, Jackson, Lane, River sub-basin: Johnson
Wasco, Deschutes, and Klamath. Creek;
Lower Deschutes
River sub-basin: Tygh Creek
and White River;
Clackamas River sub-
basin: Oak Grove Fork
Clackamas River;
Middle Willamette
River sub-basin: Mill Creek-
Willamette River and Oak
Creek;
South Santiam River
sub-basin: South Santiam
River-Hamilton Creek;
Upper Willamette
River sub-basin: Muddy
Creek;
McKenzie River sub-
basin: Upper McKenzie River
and South Fork McKenzie
River;
Middle Fork
Willamette River sub-basin:
Salt Creek-Willamette River;
Upper Deschutes
River sub-basin: Deschutes
River-McKenzie Canyon,
Deschutes River-Pilot Butte,
Deschutes River-Fall River,
and Deschutes River-Browns
Creek;
Little Deschutes
River sub-basin: Upper
Little Deschutes River,
Middle Little Deschutes
River, Lower Little
Deschutes River, Long
Prairie, and Crescent Creek;
Williamson River sub-
basin: Klamath Marsh-Jack
Creek, West of Klamath
Marsh, and Williamson River
above Klamath Marsh
Sprague River sub-
basin: North Fork Sprague
River and Sprague River
above Williamson;
Upper Klamath Lake
sub-basin: Wood River and
Klamath Lake watersheds;
Upper Klamath sub-
basin: Spencer Creek and
Jenny Creek;
Lost River sub-
basin: Lake Ewauna-Upper
Klamath River
[[Page 51663]]
California Counties: Modoc, Shasta, and Lost River sub-
Siskiyou. basin: Lower Klamath Lake
Upper Pit River sub-
basin: Pine Creek-South Pit
River (near Alturas)
Lower Pit River sub-
basin: Town of Pittville-Pit
River (near Fall River
Mills)
------------------------------------------------------------------------
* Bolded sub-basins represent the sub-basins with extant locales. Oregon
spotted frogs may not be extant in all of the historic watersheds
within these sub-basins.
Current Range/Distribution
Currently, the Oregon spotted frog is found from extreme
southwestern British Columbia south through the Puget Trough and in the
Cascades Range from south-central Washington at least to the Klamath
Basin in southern Oregon. Oregon spotted frogs occur in lower
elevations in British Columbia and Washington and are restricted to
high elevations in Oregon (Pearl et al. 2010, p. 7). In addition,
Oregon spotted frogs currently have a very limited distribution west of
the Cascade crest in Oregon, are considered to be extirpated from the
Willamette Valley in Oregon (Cushman et al. 2007, p. 14), and may be
extirpated in the Klamath and Pit River basins of California (Hayes
1997, p. 1). Currently occupied, or extant, sub-basins are those in
which Oregon spotted frogs have been found in since 2000.
In British Columbia, Oregon spotted frogs no longer occupy the
locations documented historically, but they currently are known to
occupy four disjunct locations in a single sub-basin, the Lower Fraser
River (Canadian Oregon Spotted Frog Recovery Team 2012, p. 6).
In Washington, Oregon spotted frogs are known to occur only within
six sub-basins/watersheds: The Sumas River, a tributary to the Lower
Chilliwack River watershed and Fraser River sub-basin; the Black Slough
in the lower South Fork Nooksack River, a tributary of the Nooksack
River; Samish River; Black River, a tributary of the Chehalis River;
Outlet Creek (Conboy Lake), a tributary to the Middle Klickitat River;
and Trout Lake Creek, a tributary of the White Salmon River. The
Klickitat and White Salmon Rivers are tributaries to the Columbia
River. The Oregon spotted frogs in each of these sub-basins/watersheds
are isolated from frogs in other sub-basins.
A reintroduction project was initiated in 2008, at Dailman Lake in
Pierce County on Joint Base Lewis-McChord Military Reservation. This
sub-basin (Nisqually River) was historically occupied by Oregon spotted
frogs with a documented occurrence at Kapowsin (McAllister and Leonard
1997, pp. 18-19). Eggs were collected from the Black River and the
Conboy Lake Oregon spotted frog egg-laying locations, captive reared
until metamorphosis, and released in the fall or subsequent spring.
Through 2011, researchers collected 7,870 eggs and released 3,355 frogs
(Tirhi and Schmidt 2011, pp. 51-53). Surveys in April 2011 found 3
verified Oregon spotted frog egg masses and 11 suspected egg masses.
However, egg masses were not detected in 2012. This effort is ongoing,
and the efficacy and viability of a breeding Oregon spotted frog
population being established in this area is undetermined; therefore,
this location will not be discussed further. However, should a
population be established, it would be considered to be a part of the
listed entity.
In Oregon, Oregon spotted frogs are known to occur only within
eight sub-basins: Lower Deschutes River, Upper Deschutes River, Little
Deschutes River, McKenzie River, Middle Fork Willamette, Upper Klamath,
Upper Klamath Lake, and the Williamson River. The Oregon spotted frogs
in most of these sub-basins are isolated from frogs in other sub-
basins, although Oregon spotted frogs in the lower Little Deschutes
River are aquatically connected with those below Wickiup Reservoir in
the Upper Deschutes River sub-basin. Oregon spotted frog distribution
west of the Cascade Mountains in Oregon is restricted to a few lakes in
the upper watersheds of the McKenzie River and Middle Fork Willamette
River sub-basins, which represent the remaining 2 out of 12
historically occupied sub-basins.
In California, this species has not been detected since 1918
(California Academy of Science Museum Record 44291) at historical sites
and may be extirpated (Hayes 1997, pp. 1, 35). However, there has been
limited survey effort of potential habitat and this species may still
occur in California.
Population Estimates and Status
Of the 61 historical localities where the species' previous
existence can be verified (e.g., museum specimens, photographs,
reliable published records), only 13 were confirmed as being occupied
in studies conducted in the 1990s (Hayes 1997, p. 1; McAllister and
Leonard 1997, p. 20). Hayes visited historical localities one to four
times, with a minimum of 2 hours devoted to site visits where precise
localities could be identified. For sites where the precise location
was not known, he searched three to six points in the area that
possessed favorable habitat, for 20 minutes to 3 hours, depending on
site size. Hayes also visited sites that were judged to have a high
likelihood of having Oregon spotted frogs (i.e., within the historical
range, consistent with elevations documented for verifiable specimens,
and within suitable habitat) (Hayes 1997, p. 6). Based on those
studies, Hayes (1997, p. 1) estimated the species may no longer occur
in 76 to 90 percent of its historical range. Although this estimated
loss of historical localities did not account for potential range
expansion or shifts, Oregon spotted frogs have not been subsequently
relocated in these areas. The estimated loss in historical range does
not take into account the localities found since 2000. However, the
current range of the Oregon spotted frog is significantly smaller than
the historical range, based on the best available scientific and
commercial information.
Egg mass counts are believed to be a good metric of adult
population size and are the most time-efficient way to estimate
population size (Phillipsen et al. 2010, p. 743). Adult females are
believed to lay one egg mass per year (Phillipsen et al. 2010, p. 743),
and the breeding period occurs within a reliable and predictable
timeframe each year (McAllister 2006, pers. comm.). If egg mass numbers
are collected in a single survey timed to coincide with the end of the
breeding season, when egg laying should be complete, then the egg mass
count should represent a reliable estimate of total egg masses. Because
one egg mass is approximately equivalent to one breeding female plus
one to two adult males, a rough estimate of adult population size can
be made if a thorough egg mass census is completed (Phillipsen et al.
2010, p. 743). However, using egg mass counts to estimate population
size has some weaknesses. For example, researchers have uncertainties
about whether adult females breed every year, only lay one
[[Page 51664]]
egg mass per year, and find difficulty in distinguishing individual egg
masses in large communal clusters. However, a minimum population
estimate can be derived from the total egg mass count multiplied by two
(one egg mass equals two adult frogs). While there are weaknesses in
these estimates, as discussed above, they are the best estimates
available for Oregon spotted frog numbers.
Egg mass counts, as currently conducted at most sites, do not allow
for evaluation of trends within a site nor between sites because
surveys are not standardized. Survey effort, area coverage, and timing
can differ between years at individual sites. In addition, method of
survey can differ between years at individual sites and differ between
sites. Because of the weaknesses associated with the egg mass counts,
site estimates derived from egg mass counts are considered to be a
minimum estimate and generally should not be compared across years or
with other sites. However, some breeding locations have been surveyed
in a consistent manner (in some cases by the same researcher) and for
enough years that trend data are available and considered to be
reliable. Trend information is provided in the following sub-basin
summaries for the locations where the information is available.
For the purposes of this document, the terms `location' and `site'
simply refer to the general locations where egg-laying has been
observed. In some cases, a site may be equivalent to an Oregon spotted
frog population (for example, Hosmer Lake). In other cases, a site may
include multiple egg-laying locations within wetland complexes where
hydrological connections may facilitate movement between egg-laying
areas, but where movement patterns and genetic conditions are
undetermined within the complexes (for example, Klamath Marsh NWR).
Accordingly, a site should not be interpreted to be a population.
Because of the lack of complete information between occurrence
locations, populations were not specifically identified for this status
review, and the focus of our analysis regarding the status of Oregon
spotted frogs was within the individual river sub-basins.
The following summarizes the best available scientific and
commercial information available regarding populations within the
currently occupied river sub-basins in British Columbia, Washington,
and Oregon. We used multiple data sources, including various
unpublished reports, databases, and spreadsheets provided by our
partner agencies. These sources are identified in the following
sections as ``multiple data sources'' and are included in our
literature cited list, which is included as supplementary information
on http://www.regulations.gov for this final rule. These sources are
available upon request from the Washington Fish and Wildlife Office
(see ADDRESSES). In most sub-basins, trend information regarding the
collective status of the populations within the sub-basin is limited or
not available; trend information that was available is presented below.
The status of a sub-basin may be undetermined because the Oregon
spotted frog presence has only recently been identified, the trend
information is uncertain, or sufficient survey information is not
available to indicate a trend. However, when viewed at the rangewide
scale, the Oregon spotted frog has been extirpated from most of its
historical range, and the threat of current and future impacts to the
Oregon spotted frog occurs over the entire range of the species.
Ongoing threats have significantly reduced the overall extent and
distribution of suitable habitat for the Oregon spotted frog, as
discussed below in Summary of Factors Affecting the Species.
British Columbia
Currently, Oregon spotted frogs are known to occur only within four
sites in the Lower Fraser River Basin. Of the four sites, Maintenance
Detachment Aldergrove (MD Aldergrove) is nearing, or may have reached
extirpation, as no egg masses have been discovered at the site since
2006; Mountain Slough appears to be stable; Maria Slough may be
declining; and there are limited data for the recently discovered
Morris Valley site (COSEWIC 2011, p. v). Estimates from the well-
studied populations at MD Aldergrove, Maria Slough, and Mountain Slough
indicate a population decline of 35 percent during the period 2000-2010
(COSEWIC 2011, p. 32), and the most recent egg mass counts indicate the
minimum population size for all of British Columbia is fewer than 350
adults (COSEWIC 2011, pp. 27-30). One extant population is near
extinction, and the remaining populations are small and vulnerable to
disturbance and stochastic events. Extirpation of the MD Aldergrove
population would result in a reduction of 76 percent of the extent of
Oregon spotted frog in the Lower Fraser River (COSEWIC 2011, pp. vii-
ix). Therefore, populations of Oregon spotted frogs in the Lower Fraser
River are declining.
Washington
In Washington, the Oregon spotted frog was historically found in
the Puget Trough from the Canadian border to the Columbia River, and
east to the Washington Cascades (McAllister et al. 1997, p. vii).
Current distribution is limited to four watersheds in the Puget Trough,
three that drain to Puget Sound and one that drains to the Pacific
Ocean, and two watersheds in the southeast Cascades that drain to the
Columbia River. In 1997, the locations for 11 historical populations in
Washington were verified using museum specimen and published records,
and only 1 historically known population and 2 recently discovered
populations were known to remain in Washington in 1997 (McAllister et
al. 1997, p. vii). The authors also stated that past populations of the
Oregon spotted frog in Washington are largely undocumented (McAllister
et al. 1997, p. 18). Current population estimates are based on the 2012
census of egg masses at all known extant breeding areas. Based on these
estimates, the minimum population in Washington was at least 7,368
breeding adults in 2012.
Trend data are limited; however, the Oregon spotted frog population
in the Middle Klickitat River (Conboy Lake) appears to be declining
(see below for further information). The population trend within the
rest of the occupied sub-basins is unknown. More detailed discussions
of Washington's occupied sub-basins/watersheds are provided below.
Lower Chilliwack River (Sumas River)--In 2012, one Oregon spotted
frog breeding area was found on a privately owned dairy farm on a small
tributary to the Sumas River (Bohannon et al. 2012). The Sumas River is
eventually a tributary to the Lower Fraser River, along which the
British Columbia breeding areas occur. However, the breeding area on
the Sumas River is more than 20 mi (35 km) upstream of the confluence
with the Fraser River, and separated by unsuitable aquatic habitat.
Therefore, an aquatic connection to the British Columbia breeding areas
is not likely (COSEWIC 2011, p. 12). Fewer than 50 egg masses (<100
adults) were found during the 2012 surveys; however, suitable habitat
within the Sumas River has not been surveyed extensively (Bohannon et
al. 2012) and the full extent of Oregon spotted frog distribution and
abundance has not been determined.
South Fork Nooksack River--In 2011 and 2012, Oregon spotted frog
breeding areas were found on privately owned
[[Page 51665]]
parcels in the Black Slough, a tributary of the South Fork Nooksack
River. On one parcel, the breeding habitat was in off-channel wetlands
dominated by reed canarygrass (Phalaris arundinacea) and recent shrub
plantings. Breeding areas on other parcels were located within former
pasture lands that had been planted with trees and fenced within the
last 2 or 3 years under the Conservation Reserve Enhancement Program
(CREP) to eliminate grazing and improve water quality (Bohannon et al.
2012). At least 230 adults (based on 2012 surveys) are associated with
the known breeding areas along the Black Slough; however, this area has
not been surveyed extensively (Bohannon et al. 2012), and the full
extent of Oregon spotted frog distribution and abundance has not been
determined.
Samish River--In 2011 and 2012, Oregon spotted frog breeding areas
were found on privately owned parcels along the upper reaches of the
Samish River. All of the breeding areas are seasonally flooded grazed
or formerly grazed pasture lands that are predominantly reed
canarygrass (Bohannon et al. 2012). At least 1,220 adults (based on
2012 surveys) are associated with the known breeding areas along the
Samish River; however, this area has not been surveyed extensively, and
the full extent of Oregon spotted frog distribution and abundance has
not been determined.
Black River--Oregon spotted frogs occupy wetlands in the floodplain
and tributaries of the upper Black River drainage between Black Lake
and the town of Littlerock. They are currently known to occur at three
locations within the Black River floodplain (Blooms Ditch near 110th
Avenue Bridge, near 123rd Avenue, and the confluence with Mima Creek)
and in four tributaries: Dempsey Creek, Salmon Creek, Allen Creek, and
Beaver Creek (Hallock 2013; WDFW and USFWS multiple data sources). In
2012 and 2013, new breeding locations were detected along Fish Pond
Creek system, which flows directly into Black Lake, not Black River.
Oregon spotted frog breeding areas in the Black River may be isolated
from each other and the frogs associated with the Fish Pond Creek may
not be hydrologically connected to frogs in the Black River due to the
human alteration of the Black Lake drainage pattern. Further
investigation of this recently discovered area is needed.
The full extent of the population's distribution, abundance, and
status in the Black River has not been determined. The Black River
adult breeding population was comprised of at least 1,748 breeding
adults in 2012 (Hallock 2013, p. 27) and 3,330 breeding adults in 2013
(WDFW multiple data sources). Oregon spotted frogs in Dempsey Creek
have been monitored relatively consistently since the late 1990s. Other
breeding areas in the Black River have been monitored inconsistently or
were recently found, and surveys to identify additional breeding
locations continue. The Dempsey Creek breeding area may be declining,
but the trend for the remainder of the occupied areas is undetermined.
White Salmon River (Trout Lake Creek)--Oregon spotted frogs occupy
approximately 1,285 ac (520 ha) of the lower Trout Lake Creek
watershed, ranging in elevation 1,960-2,080 ft (597-633 m). In total,
as of 2012, a minimum population estimate of 2,124 breeding adults
(Hallock 2012) associated with 12 breeding areas have been identified.
Two of the breeding areas have been monitored since they were found by
Leonard (1997). The other locations have been monitored sporadically
since they were discovered. Monitoring of egg mass numbers at two
breeding areas within the Trout Lake NAP revealed considerable
population volatility and a general pattern of decline from 2001
through 2007 (Hallock 2011, p. 8). During the period of egg mass
declines, three events of note occurred that could have influenced
frogs at the NAP: Annual precipitation was unusually low, cattle
grazing was reduced and then eliminated, and frogs infected with
chytrid fungus (Batrachochytrium dendrobatidis (Bd)) were present
(Pearl et al. 2009b, Hayes et al. 2009). While the 2009 through 2012
egg mass counts indicate that Oregon spotted frog numbers may be
rebounding within the eastern portions of the NAP, the numbers in the
western portion continue to be less than half of the estimates from the
1990s (Hallock 2012, entire).
Middle Klickitat River (Conboy Lake)--The extent of Conboy Lake
wetland complex habitat occupied by Oregon spotted frogs at high water
is approximately 7,462 ac (3,020 ha), ranging in elevation from 1,804-
1,896 ft (550-576 m). This wetland complex comprises two lakebeds that
are entirely seasonal (except in wet years) and are joined by Camas
Ditch, which flows into Outlet Creek, the main drainage for the system
that flows northeast into the Klickitat River. There were a minimum of
1,954 breeding adults in the Conboy Lake wetland complex in 2012
(Hallock 2013, p. 27) and 2,714 breeding adults in 2013 (Wilson, in
lit. 2013). This used to be the largest Oregon spotted frog population
throughout the entire range (highest egg mass count 7,018 in year
1998). However, Oregon spotted frog egg mass surveys suggest a
continued long-term decline (approximately 86 percent) since 1998
(Hayes and Hicks 2011, unnumbered pp. 5-6; Hallock 2013, p. 36). This
area is subject to similar levels of precipitation as Trout Lake NAP
and frogs infected with Bd were also present (Pearl et al. 2009b, Hayes
et al. 2009); however, unlike Trout Lake NAP, Oregon spotted frog
numbers in this sub-basin are not rebounding. At present, the
population trend of Oregon spotted frogs in the Middle Klickitat River
is considered to be declining.
Oregon
Population estimates of Oregon spotted frogs in Oregon are
primarily based on egg mass surveys conducted in 2011 and 2012 at known
extant sites, and newly discovered occupied areas that had been
unsurveyed prior to 2012. Population estimates for the Middle Fork
Willamette River sub-basin are based on mark-recapture studies
conducted by U.S. Geological Survey (USGS) in 2011, rather than egg
mass surveys. Based on these survey data, the minimum population
estimate in Oregon consists of approximately 12,847 breeding adults.
More detailed discussions of Oregon's occupied sub-basins are provided
below and are available in our files.
Lower Deschutes River--Within the Lower Deschutes River sub-basin,
a single extant population of Oregon spotted frog occurs at Camas
Prairie, an 82-ac (33-ha) marsh located along Camas Creek in the White
River watershed. The Camas Prairie Oregon spotted frogs are the most
geographically isolated, carry several alleles that are absent or rare
in other sites, and have the lowest genetic diversity of Oregon spotted
frogs rangewide (Blouin et al. 2010, p. 2185). The frogs at this
location appear to be the only remaining representatives of a major
genetic group that is now almost extinct (Blouin et al. 2010, p. 2190).
Since 2004, egg mass surveys have been conducted annually, and the
population trend has been positive. Based on the 2012 egg mass count,
the minimum population size of breeding adults is 152 (Corkran 2012,
pers. comm.). Although the population trend has been positive at the
single known location, the number of individuals in the population
remains low.
Upper Deschutes River--Oregon spotted frogs in the Upper Deschutes
River sub-basin occur in high-elevation lakes up to 5,000 ft (1,524 m),
wetland ponds, and riverine wetlands and oxbows along the Deschutes
River.
[[Page 51666]]
There are fewer than 20 known breeding locations within four watersheds
(HUC 10) in the sub-basin: Charleton Creek, Browns Creek, Fall River,
and North Unit Diversion Dam. Most of the known breeding locations are
on the Deschutes National Forest in lakes, ponds, and riverine wetlands
that drain to the Crane Prairie and Wickiup Reservoir complex,
including the use of the wetland margins of the reservoirs. There are
at least five known breeding locations downstream of Wickiup Reservoir
in riverine wetlands along the Deschutes River, extending to Bend,
Oregon: Dead Slough, La Pine SP, Sunriver, Slough Camp, and the Old
Mill casting pond, including Les Schwab Amphitheater (LSA) Marsh.
Dilman Meadow drains into the Deschutes River below Wickiup Dam via an
unnamed tributary.
The consistency of population surveys varies by breeding site, and
population trend information is limited. Only two sites within the sub-
basin have been monitored consistently since the early 2000s and show
an increasing population trend: Dilman Meadow and Sunriver (USGS and J.
Bowerman 2000 through 2012 datasets). Trend data are not available for
the remainder of populations within the Upper Deschutes River sub-
basin. Sunriver, located downstream of Wickiup Reservoir, is the
largest population of Oregon spotted frogs within the Upper Deschutes
River sub-basin with a population of at least 1,454 breeding adults
based on 2012 egg mass surveys (J. Bowerman dataset 2012). A minimum
population estimate for the Upper Deschutes River sub-basin (including
Sunriver) is approximately 3,530 breeding adults based on surveys since
2006 (USGS 2006 to 2012 and J. Bowerman 2012 datasets).
Little Deschutes River--Oregon spotted frogs are distributed
throughout wetland, pond, and riverine habitats in the Little Deschutes
River sub-basin, which drains an area of approximately 1,020 square
miles (2,600 square km) and flows north from its headwaters in northern
Klamath County to its convergence with the Deschutes River 1 mi (1.2
km) south of Sunriver and approximately 20 mi (32 km) south of Bend,
Oregon. The Little Deschutes River is approximately 92 mi (148 km)
long. Approximately 23 known breeding locations (as of 2012) are within
five watersheds in the sub-basin: Upper, Middle, and Lower Little
Deschutes River; Crescent Creek; and Long Prairie. Big Marsh, a 2,000-
ac (809 ha) wetland located within headwaters at 4,760 ft (1,451 m)
elevation on the Deschutes National Forest, has the largest monitored
population of Oregon spotted frogs in the Little Deschutes River sub-
basin and possibly rangewide. The estimated population size of Big
Marsh based on a 2012 U.S. Forest Service (USFS) egg mass survey is
5,324 breeding adults (male and female) (USFS data 2012).
Because 70 percent of the sub-basin is privately owned and mostly
unsurveyed, a population estimate for the entire Little Deschutes River
sub-basin is difficult to determine. A minimum population estimate of
Oregon spotted frogs based on limited survey data from public and
private lands in 2012 is approximately 6,628 breeding adults (including
Big Marsh above). However, the vast acreage of wetland complexes and
suitable habitat for Oregon spotted frogs along the mainstem Little
Deschutes River and Crescent Creek indicate that the frog population
within the unsurveyed areas may be well above this estimate. Although
the trend of the frog population at Big Marsh appears to be increasing
based on USFS surveys from 2002 to 2012 (USFS 2002-2012), the
population trend of the remainder of frogs within the sub-basin is
undetermined.
McKenzie River--Oregon spotted frogs in the McKenzie River sub-
basin are located within the South Fork McKenzie River watershed in an
area referred to as the Mink Lake Basin in the wilderness of the
Willamette National Forest. There are two known breeding populations:
One at Penn Lake and one at an unnamed marsh 0.28 mi (0.45 km) north of
Mink Lake. The Penn Lake and Unnamed Marsh populations are about 0.93
mi (1.5 km) apart and are not hydrologically connected via surface
water. Mark-recapture monitoring of these populations has been
conducted by USGS from 2007 through 2011 (Adams et al. 2007; 2008, p.
13; 2009, p. 14; 2010, p. 14; and 2011, p. 14). A population estimate
for breeding adults in the McKenzie River sub-basin, based on mark-
recapture efforts by USGS in 2011 is 217 (i.e., 179 at Penn Lake and 38
at Unnamed Marsh) (Adams et al. 2011). However, trend has not been
estimated for these populations.
Middle Fork Willamette River--Oregon spotted frogs in the Middle
Fork Willamette River sub-basin are limited to a single population at
Gold Lake and bog, located in the 465-ac (188-ha) Gold Lake Bog
Research Natural Area on the Willamette National Forest within the Salt
Creek watershed. This population is one of three remaining populations
of Oregon spotted frogs west of the Cascade mountain crest in Oregon.
The Gold Lake Bog site consists of three small ponds over an area of
approximately 3.7 ac (1.5 ha) within a larger bog where three major
streams converge. Breeding surveys are periodically conducted by USGS
and the Willamette National Forest. However, long-term trend data are
lacking for this site. Based on USGS egg mass surveys in 2007, the
estimated population size is approximately 1,458 breeding adults (USGS
datasets).
Williamson River--Oregon spotted frogs in the Williamson River sub-
basin occur in two watersheds: Klamath Marsh/Jack Creek and Williamson
River above Klamath Marsh and consist of three populations: Jack Creek,
Klamath Marsh NWR, and the Upper Williamson River. Data from 1996
through the present suggest the Jack Creek population is declining, and
the survey data from 2000 through the present suggest that the Klamath
Marsh population is stable. Additional data collected in 2013
documented a downstream extension of occupied habitat in Jack Creek
(Pearl 2014, pers. comm.). These watersheds are a mixture of both
private and public (U.S. Bureau of Land Management (BLM), USFS, and
NWR) lands and consist of both wetland and riverine potential habitats
from 4,500 to 5,200 ft (1,371 to 1,585 m) in elevation. As of 2011, the
minimum population estimate for the sub-basin is approximately 376
breeding individuals (male and female) (KMNWR 2011, USFS 2012, USGS
multiple datasets). Permission to survey adjacent private lands has not
been obtained; however, the private lands surrounding the public lands
appear to have suitable habitat and likely contain additional breeding
complexes and individuals.
Upper Klamath Lake--Oregon spotted frogs in the Upper Klamath Lake
sub-basin occupy two watersheds that flow into Upper Klamath Lake:
Klamath Lake and Wood River. There are four populations in this sub-
basin: Crane Creek, Fourmile Creek, Sevenmile Creek, and the Wood River
channel and the adjacent but separate BLM Wood River canal. Additional
surveys completed in 2013 revealed occupied habitat in Sun Creek, Annie
Creek, and more locations of Crane Creek and Sevenmile Creek (Hering
2014, pers. comm.; Pearl 2013, pers. comm.). These populations occur in
both riverine and wetland habitats. Historically, these two watersheds
were hydrologically connected. Survey efforts on Fourmile Creek,
Sevenmile Creek, and the Wood River channel have been sporadic while
Crane Creek and the BLM Wood River canal have been surveyed annually.
These data suggest that there is still insufficient information to
obtain population trends for all but the BLM Wood River canal
population, which is
[[Page 51667]]
declining. As of 2011, the minimum population estimate for the sub-
basin is approximately 374 breeding individuals (male and female) (USGS
multiple datasets, BLM multiple datasets). Permission to survey
adjacent private lands has not been obtained; however, the private
lands surrounding the known populations appear to have suitable habitat
and likely contain additional breeding complexes and individuals. Trend
data are lacking for three out of four populations in the Upper Klamath
Lake.
Upper Klamath--Oregon spotted frogs in the Upper Klamath sub-basin
occupy two lacustrine habitats: Parsnip Lakes in Jackson County and
Buck Lake in Klamath County. Both of these sites are isolated
hydrologically by great distances (>20 mi (32 km)) and hydrological
barriers (inhospitable habitat and dams) to other sites in the Klamath
Basin. Historical surveys in this sub-basin resulted in a population
estimate of about 1,170 adults (range of <0 to 2,379, 95 percent
confidence interval) (Hayes 1998a, p. 10; Parker 2009, p. 4). Due to
insufficient survey data, population trend information is not available
for the Parsnip Lakes population. The most recent surveys found 18 egg
masses or 36 breeding individuals (male and female) at Parsnips Lakes
(Parker 2009). Surveys conducted at Buck Lake suggest a population
decline and have documented most recently small numbers of egg masses
(38 masses in 2010), or the equivalent of 76 breeding individual (male
and female) (BLM 2012). Additional information indicates that suitable
habitat occurs downstream of Buck Lake within Spencer Creek (Smith
2014, pers. comm.). The minimum population estimate for this sub-basin
is currently estimated to be 112 breeding individuals suggesting
drastic population declines since 1998.
Summary of Current Population Range and Trend
Oregon spotted frogs may no longer occur in as much as 90 percent
of their historically documented range, including all of the historical
localities in California (i.e., 90 percent of the historical areas are
no longer occupied). Currently, the Oregon spotted frog is found in 15
sub-basins ranging from extreme southwestern British Columbia south
through the Puget Trough, and in the Cascades Range from south-central
Washington at least to the Klamath Basin in Oregon. Oregon spotted
frogs occur in lower elevations in British Columbia and Washington and
are restricted to higher elevations (i.e., 3,160 to 5,200 ft (963 to
1,585 m) in Oregon. In addition, Oregon spotted frogs currently have a
very limited distribution west of the Cascade crest in Oregon and are
considered to be extirpated from the Willamette Valley.
In most sub-basins, trend information regarding the collective
status of the populations within the sub-basin is limited or not
available. The best scientific and commercial information available
indicates the trend is undetermined for Oregon spotted frog populations
in 13 of the sub-basins and is declining in the Lower Fraser River and
Middle Klickitat sub-basins. Threats to the remaining populations are
ongoing or increasing, however, as described below.
Summary of Factors Affecting the Species
Section 4 of the Act (16 U.S.C. 1533), and its implementing
regulations at 50 CFR part 424, set forth the procedures for adding
species to the Federal Lists of Endangered and Threatened Wildlife and
Plants. Under section 4(a)(1) of the Act, we may list a species based
on any of the following five factors: (A) The present or threatened
destruction, modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; and (E) other natural or manmade
factors affecting its continued existence. Listing actions may be
warranted based on any of the above threat factors, singly or in
combination. Each of these threats/factors is discussed below.
Threats for the Oregon spotted frog were assessed by breeding
locations and occupied watersheds, then summarized by occupied sub-
basin in this final rule. Each of the five threat categories were
summarized by sub-basin using the unified threats classification system
(loosely based on the IUCN-CMP (World Conservation Union-Conservation
Measures Partnership)), best available data, and best professional
judgment. We summarized threats in each occupied sub-basin for scope,
severity, impact, timing, and stress, to ensure our determination would
be based on the best scientific and commercial data available, as
required under section 4(b)(1)(A). Scope is the proportion of the
occupied area within the sub-basin that can reasonably be expected to
be affected. Severity is the level of damage to the species from the
threat that can reasonably be expected. Impact summarizes the degree to
which a species is observed, inferred, or suspected to be directly or
indirectly affected and is based on the combination of the severity and
scope rating (for example, if the severity and scope ratings were both
high, then the impact rating was high). Timing is the immediacy of the
threat (i.e., is the threat ongoing, could happen in the short term, or
is only in the past). Stress is the key ecological, demographic, or
individual attribute that may be impaired or reduced by a threat. The
completed analysis (Threats Synthesis Rangewide Analysis) is available
at http://www.regulations.gov and http://www.fws.gov/wafwo. The
syntheses by threat categories are included in the following threat
factor discussions.
Large historical losses of wetland habitat have occurred across the
range of the Oregon spotted frog. Wetland losses are estimated from
between 30 to 85 percent across the species' range with the greatest
percentage lost having occurred in British Columbia. These wetland
losses have directly influenced the current fragmentation and isolation
of remaining Oregon spotted frog populations.
Loss of natural wetland and riverine disturbance processes as a
result of human activities has and continues to result in degradation
of Oregon spotted frog habitat. Historically, a number of disturbance
processes created emergent wetlands favorable to Oregon spotted frogs
throughout the PNW: (1) Rivers freely meandered over their floodplains,
removing trees and shrubs and baring patches of mineral soil; (2)
beavers created a complex mosaic of aquatic habitat types for year-
round use; and (3) summer fires burned areas that would be shallow
water wetlands during the Oregon spotted frog breeding season the
following spring. Today, all of these natural processes are greatly
reduced, are impaired, or have been permanently altered as a result of
human activities, including stream bank, channel, and wetland
modifications; operation of water control structures (e.g., dams and
diversions); beaver removal; and fire suppression.
The historical loss of Oregon spotted frog habitats and lasting
anthropogenic changes in natural disturbance processes are exacerbated
by the introduction of reed canarygrass, nonnative predators, and
potentially climate change. In addition, current regulatory mechanisms
and voluntary incentive programs designed to benefit fish species have
inadvertently led to the continuing decline in quality of Oregon
spotted frog habitats in some locations. The current wetland and stream
vegetation management paradigm is generally a no-management or
restoration approach that often results in succession to a tree- and
[[Page 51668]]
shrub-dominated community that unintentionally degrades or eliminates
remaining or potential suitable habitat for Oregon spotted frog
breeding. Furthermore, incremental wetland loss or degradation
continues under the current regulatory mechanisms. If left unmanaged,
these factors are anticipated to result in the eventual elimination of
remaining suitable Oregon spotted frog habitats or populations. The
persistence of habitats required by the species is now largely
management-dependent.
Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range
Threats to the species' habitat include changes in hydrology due to
construction of dams and human-related alterations to seasonal
flooding, introduction of nonnative plant and animal species,
vegetation succession and encroachment, poor water quality, livestock
grazing (in some circumstances), and residential and commercial
development.
Habitat losses and alterations affect amphibian species in a
variety of ways, including reducing or eliminating immigration through
losses of adjacent populations (see ``Factor E'') and effects on
critical aspects of the habitat (Hayes and Jennings 1986, pp. 492-494).
These critical aspects include suitable egg-laying and nursery sites,
refuges from predation or unfavorable environmental conditions, and
suitable temperatures necessary for egg laying, growth, and development
(Hayes and Jennings 1986, pp. 492-494).
Because Oregon spotted frogs have specific habitat requirements,
they are particularly vulnerable to habitat alterations: (1) A
restricted number of communal egg-laying locations are used year after
year; (2) the species' warm water microhabitat requirement results in
habitat overlap with introduced warm water fish species and other warm
water fauna that prey on Oregon spotted frogs (for example, bullfrogs);
(3) the availability of suitable warm water habitat, a requirement in
the active season, is generally limited in the cool climate of the PNW;
(4) the species is vulnerable to the loss or alteration of springs used
for overwintering; and (5) their habitat requirements (for example,
spatial structure) for overwintering, active season, and breeding
habitats are more complex than for other frog species (Hayes et al.
1997, p. 4). In addition, breeding habitat is arguably the single most
important habitat component for many aquatic-breeding amphibians
because amphibian embryos and larvae depend on aquatic habitats for
survival (Leonard 1997, p. 1).
Loss of Wetlands
British Columbia--Extensive diking of river ways and draining of
Sumas Lake for conversion to agriculture significantly modified
drainage patterns and resulted in loss of associated wetlands in the
Fraser River lowlands of British Columbia (COSEWIC 2011, p. 20). Boyle
et al. (1997, p. 190) estimated an 85 percent loss of habitat types
preferred by Oregon spotted frogs (fen, swamp/bog/marsh) between 1820
and 1990. Moore et al. (2003 cited in COSEWIC 2011) found wetland loss
continued between 1989 and 1999 as a result of urban and agricultural
encroachment. Agricultural land use changes, such as the conversion of
field habitat to blueberry and cranberry production, has led to impacts
through drain tile installation and riparian area encroachment/erosion.
Sediment deposition into streams and wetlands by runoff from adjacent
agricultural fields can impact Oregon spotted frog breeding habitat by
changing the channel/wetland shape and depth (Lynch and Corbett 1990).
Land conversion for agriculture is ongoing at Mountain Slough and to
some extent at Maria Slough and Morris Valley (COSFRT 2012, p. 24),
within Oregon spotted frog habitat.
Washington--Estimates for Washington indicate that over 33 percent
of wetlands were drained, diked, and filled between pre-settlement
times and the 1980s (Canning and Stevens 1990, p. 23); losses in the
historical range of the Oregon spotted frog are even higher because of
the high degree of development in the low elevations of the Puget
Trough (McAllister and Leonard 1997, p. 22).
Major alterations to Conboy Lake wetland complex in Washington
began when settlers started moving to Glenwood Valley in the late
1800s. Wet meadows were drained through a series of canals, ditches,
and dikes largely developed between 1911 and 1914, and remain today.
The five creeks that flow into this wetland complex and the Cold
Springs ditch are entirely channelized within the wetland complex.
Ditching, filling, and other habitat alterations have resulted in
little or no retention of surface water in the late-season lakebeds
(Conboy Lake and Camas Prairie), reducing the amount of aquatic habitat
available for the Oregon spotted frog. The historical Conboy lakebed is
believed to have retained water for 10 to 12 months in most years.
Currently, it retains water only during wet years and is purposefully
drained annually to control bullfrogs (Ludwig 2012, pers. comm.). The
Camas Prairie portion of Glenwood Valley retains water year-round over
a small area and only in wet years. Typically, aquatic habitat is
reduced to about 1,000 ac (400 ha) during the late summer and early
fall (Hayes et al. 2000), and once the seasonal lakebeds dry, the
network of ditches and channels provide the only aquatic habitat for
Oregon spotted frogs. In order to maintain sufficient flow through the
system, a small area of Bird Creek must be excavated every 2 to 3 years
to remove the high level of sand and gravel that is deposited annually
from upstream. Most of the other ditches have been cleaned on a much
less frequent basis (intervals of up to 20 years), although in the
future, the Conboy Lake NWR plans to clean select reaches on a 5-10
year cycle (Ludwig 2012, pers. comm.).
Oregon--Historical losses of wetland in Oregon are estimated at 38
percent between pre-settlement times and the 1980s with 57 and 91
percent of these losses concentrated in the Willamette Valley and
Klamath Basin, respectively (Dahl 1990). Wetland loss continues in the
Willamette Valley (Daggett et al. 1998; Morlan et al. 2005). Between
1982 and 1994, a net loss of 6,877 ac (2,783 ha) of wetlands (2.5
percent of the 1982 wetland area) occurred, primarily due to conversion
to agriculture (Daggett et al. 1998 p. 23), and between 1994 and 2005,
an estimated additional net loss of 3,932 ac (1,591 ha) (1.25 percent
of the 1994 wetland area) took place, primarily due to development
(Morlan et al. 2010. pp. 26-27). Oregon spotted frogs are believed to
be extirpated from the Willamette Valley.
Human alteration of wetlands in the central Oregon Cascades has had
less severe effects since many of the sites inhabited by the Oregon
spotted frog are located at high elevation and within lakes and
wetlands located on Federal lands managed by the USFS. However, damming
and diverting water for irrigation needs has resulted in the loss of
wetlands within the Upper Deschutes sub-basin beginning in the early
1900s (see hydrology section below). Wetland loss is also an ongoing
threat to Oregon spotted frogs within the Little Deschutes River sub-
basin in south Deschutes County, where land development has increased
since the 1960s.
A substantial amount of wetland habitat in the Klamath Basin has
been drained and converted to other uses, primarily for grazing and
row-crop production, although the extent of this loss is difficult to
estimate due to a lack of accurate historical data (Larson and Brush
2010). The majority of wetland
[[Page 51669]]
degradation and alteration took place in the southern part of the upper
basin, where extensive drainage occurred at Tule and Lower Klamath
Lakes in the early 20th century (Larson and Brush 2010, p. 4). Wetlands
at the north end of the basin, including Sycan Marsh, Klamath Marsh,
Upper Klamath Lake, and in the Wood River Valley, have also suffered
extensive hydrologic alteration. Ongoing losses are currently minimized
due to strict regulations governing wetlands, and there are no known
ongoing losses of wetlands in the Klamath Basin. In addition,
restoration efforts are under way in the Klamath Basin (see
``Conservation Efforts to Reduce Habitat Destruction, Modification, or
Curtailment of Its Range''), reversing wetland losses to some degree.
However, because of subsidence, reconnection of former wetlands to
Upper Klamath Lake resulted in these areas being too deep to support
marsh vegetation, and many of these areas do not support the variety of
wildlife that they did formerly when they were marshes. Therefore,
these wetlands are unlikely to provide all of their former functions.
Loss of Wetlands Conclusion--Historical loss of wetlands has been
extensive throughout the range of the species, and is the primary
reason for the absence of the species from as much as, or more than, 90
percent of its former range (also see Historical Range/Distribution).
Land conversions that result in loss of wetlands are continuing
throughout the range. Wetlands continue to be lost or degraded in at
least 10 of the 15 occupied sub-basins. Even though these losses are
occurring at much lower rates than in the past because of Federal and
State regulations that pertain to wetlands (see Factor D), the ongoing
loss of wetlands continues to pose a threat to the Oregon spotted frog.
Hydrological Changes
Changing water levels at critical periods in the Oregon spotted
frog's life cycle, whether natural or human-induced, has negatively
affected the species. Lowered water levels have exposed individuals to
predation by reducing cover and confining them to smaller areas where
they are more vulnerable to predators (see also Factor C). Water level
reduction during the breeding season, due to both natural and
anthropogenic causes, has resulted in the loss of the entire
reproductive effort for the year due to stranding and desiccation of
the egg masses in British Columbia (Licht 1971, p. 122; COSFRT 2012, p.
18), Washington (Lewis et al. 2001, p. 8; Hayes et al. 2000, pp. 6-7),
and Oregon (Pearl and Hayes 2004, p. 24). Excessive seasonal flooding
at critical periods has also resulted in the loss of shallow wetlands
needed for egg-laying and development.
Most of the currently occupied Oregon spotted frog sites face
threats from changes in hydrology. Twenty-one of twenty-eight (75
percent) sites surveyed in Washington and Oregon have had some human-
related hydrological alterations, ranging from minor changes (for
example, local ditching around springs) to substantial changes,
including major modifications of historical flow patterns (Hayes 1997,
p. 43; Hayes et al.1997, p. 6). Oregon spotted frogs in four of the
occupied sub-basins (Lower Fraser River, Middle Klickitat River, Little
Deschutes River, and Upper Klamath) are experiencing high to very high
impacts due to ongoing hydrological changes based on the unified
threats classification system ranking, described above. The altered
hydrology has affected both breeding and wintering habitat, as
discussed below.
Water Diversions/Manipulations--Dams in the upper watersheds of the
Puget Trough, Willamette Valley, and the Deschutes River have
significantly reduced the amount of shallow overflow wetland habitat
that was historically created by natural flooding (Cushman and Pearl
2007, pp. 16-17). The inundation of large marsh complexes, and habitat
fragmentation by the construction of reservoirs in the Cascades, has
also eliminated and degraded Oregon spotted frog habitat. We are not
aware of proposals for construction of new dams or reservoirs that
would pose a threat to the existing Oregon spotted frog populations in
British Columbia, Washington, or Oregon. However, the operation of
existing dams/diversions/water control structures in Washington and
Oregon continues to affect populations of Oregon spotted frogs due to
extreme water fluctuations between and within years. These operations
inundate and desiccate Oregon spotted frog habitat, while creating and
maintaining habitat suitable for nonnative predaceous species.
Water management in the Glenwood Valley, Washington (Middle
Klickitat River sub-basin), appears to be playing a significant role in
the decline of the Oregon spotted frog in this sub-basin. Water
management in this area is complex due to the juxtaposition of private,
county, and federal lands, and the location and ownership of water
diversion structures. The need to retain water on the Conboy Lake NWR
for resources, including the Oregon spotted frog, conflicts with needs
of the intermingled and adjacent private landowners who want water
drawn down in order to grow reed canarygrass for haying or to graze
cattle. In addition, water management on the NWR is constrained by
failing dikes, plugged ditches, undersized culverts, and lack of water
control structures (USFWS 2012, p. 27). Dewatering by Conboy Lake NWR
generally begins June 1, but begins as early as April on privately held
lands, which also results in the dewatering of some refuge lands (USFWS
2012, p. 28). The Camas Prairie area of the valley is drained annually
to facilitate production of hay and grazing opportunities (USFWS 2012,
p. 28).
Dewatering breeding areas during the egg stage results in
desiccation of Oregon spotted frog egg masses. Dewatering during the
rearing stage results in tadpole mortality if water is not retained
through metamorphosis. Physical barriers created by the dike system
hinder young frogs (recently metamorphosed) from moving into permanent
waters, especially when water is drawn down too quickly or a surface
water connection to permanent water is not retained. Disconnection from
permanent water occurs in some places in the valley, which results in
young frogs becoming stranded and dying. In the areas where a
connection to permanent water is retained and frogs are able to move
with the water, the frogs become concentrated in smaller areas with
predators such as fish and bullfrogs or become easy targets for
terrestrial predators (Engler 2006, pers. comm.). This issue is
complex, because the nonnative bullfrog is fairly common on the refuge,
and studies indicate they can prey heavily on native frog species,
including Oregon spotted frog.
Water management can be used as a method to reduce bullfrog tadpole
survival by drying up seasonal wetlands completely by early fall.
However, widespread drawdowns for bullfrog tadpole control can conflict
with the need to provide rearing, movement, and summertime water for
Oregon spotted frogs (USFWS 2010b, pp. 36, 63, 67). Surveys since 1998
have documented extensive annual declines in Oregon spotted frog egg
mass numbers due to early water drawdowns and perennially low water;
therefore, inadequate water or poorly timed water management activities
continue to be a threat to Oregon spotted frog that has a significant
negative impact on recruitment (the addition of young individuals to
the adult population) and survival in the Middle Klickitat River sub-
basin.
[[Page 51670]]
In the Upper Deschutes River sub-basin in Oregon, regulated water
releases from Crane Prairie and Wickiup Reservoirs result in extreme
seasonal fluctuations in stream flows that have affected the amount of
overwintering and breeding habitat available for Oregon spotted frogs.
Prior to the construction of Wickiup Dam in 1947, the Deschutes River
below the current dam site exhibited stable flows averaging
approximately 730 cubic feet per second (cfs) (20.7 cubic meters per
second (cms)) and 660 cfs (18.7 cms) during summer and winter,
respectively (Hardin-Davis 1991). Water storage in the reservoirs
during winter, water releases in the spring, and water diversions for
irrigation result in extremely low winter flows (October through March)
in the Deschutes River below Wickiup Dam of approximately 20-30 cfs
(0.6-0.8 cms) and high summer flows (July and August) of approximately
1,400 cfs (39.6 cms). Because water releases from Wickiup Reservoir
typically occur in early to mid-April, potential breeding habitats
downstream of Wickiup Dam on the mainstem Deschutes River may not have
sufficient water during the breeding season to facilitate frog movement
and breeding unless supported by springs.
Currently, Oregon spotted frog breeding is known to occur in five
areas downstream of Wickiup Reservoir along the Deschutes River: Dead
Slough, La Pine State Park, Sunriver, Slough Camp, and Old Mill casting
pond (including adjacent LSA marsh). Oregon spotted frog habitat at
Sunriver Resort has been managed and maintained by Sunriver Nature
Center by using weirs to stabilize the water levels from the beginning
of the breeding season through metamorphosis, which has resulted in a
large and fairly stable population of Oregon spotted frogs, despite the
low river flows during the breeding season. Breeding and dispersal of
metamorphosing frogs at the Slough Camp site is likely affected by the
seasonal timing of storage and release of water from the reservoir each
year. Adults have been observed at the inlet to Slough Camp (east side)
prior to the flow releases from the reservoir in early April (Higgins
2012, pers. comm.), indicating that frogs may be staging to access
breeding habitat that becomes accessible when flows are released for
the irrigation season. At the onset of the storage season in October,
the east side of Slough Camp drains rapidly of water, which could
result in stranding of frogs that have bred and reared in this
location. In 2012, Oregon spotted frogs were discovered in a water
retention pond at The Old Mill District shops and in a riverine marsh
(LSA marsh) across from the pond in downtown Bend, Oregon. The shallow
pond, located within 20 ft (6 m) of the Deschutes River, is managed to
provide year-round water that supports overwintering frogs. However,
the impacts of regulated river flows to Oregon spotted frogs within the
LSA marsh remain to be evaluated.
Oregon spotted frog habitat in the Little Deschutes River sub-basin
in Oregon are affected by regulated water management downstream of
Crescent Lake Dam in Crescent Creek and the Little Deschutes River
below the confluence with Crescent Creek. Regulated water releases from
Crescent Lake typically occur in June, just after the breeding season.
Egg mass stranding has been observed on three separate occasions along
the Little Deschutes River, downstream of the confluence with Crescent
Creek, prior to the release of irrigation water (Demmer 2012, pers.
comm.). Overwintering habitats may be limited when flows from Crescent
Lake typically cease in October at the onset of the storage season.
Groundwater may be ameliorating the impacts from the regulated water
management in Crescent Creek in locations where groundwater discharges
to the stream (Gannett et al. 2001), but a full analysis has not yet
been conducted.
In the Klamath Basin, the Upper Klamath sub-basin populations may
be affected by water diversion at Hyatt and Keene Creek dams. Hyatt and
Keene Creek dams may divert up to 136 cfs of flow from Keene Creek, in
the Klamath Basin, for agricultural, municipal and industrial, and
hydroelectric power generation in the Rogue basin (OWRD 2002, 2008).
While there is no known surface or subsurface connection between the
operation of these facilities and Oregon spotted frog populations in
the Parsnip Lakes, these dams may affect flows in Keene Creek, where
isolated juvenile Oregon spotted frogs have been observed (Parker 2009,
p. 5). The precise effect of water diversion at these facilities on
habitat conditions is unknown and has been complicated by grazing
practices and the loss of beaver dams in the area (Parker 2009, p. 5).
While these facilities reduce Keene Creek flows during the winter and
spring, groundwater contributions from Keene Creek reservoir may
contribute to wetland conditions during dry summer conditions.
Development--Other hydrological changes result from the development
of homes and roads adjacent to wetlands with Oregon spotted frogs.
Development introduces new impervious surfaces, which increase the
amplitude and frequencies of peak highs and lows in water levels, a
hydrologic characteristic that has been implicated in reduced amphibian
species diversity in wetlands in King County, Washington (Richter and
Azous 1995, p. 308). (See ``Development'' section below for further
discussion.) Manmade barriers (e.g., culverts) on roads that intersect
streams, rivers, and/or wetlands that disconnect or increase the
amplitude of flow may prevent or impede Oregon spotted frog movements
between breeding areas and other habitats. However, the extent or
severity of this threat is not determinable at this time.
Drought--Changes in water levels due to drought, and exacerbated by
human modification, have caused seasonal loss of habitat and
degradation of essential shoreline vegetation that has resulted in
reduced recruitment regionally (Licht 1971, p. 122; Licht 1974, p.
623). In 1997, Hayes identified 14 of 24 (58 percent) Oregon spotted
frog breeding locations across the extant range as having a moderate to
high risk from drought (1997, pp. 43-45). Drought risk was based on the
potential for a drop in water level that could reduce or eliminate the
species' habitat. Sites with the greatest risk included those sites
with low precipitation levels and sites dependent upon surface flow
rather than flow from springs. Sites with the greatest risk from
drought are in the Klamath and Deschutes River basins of Oregon (Hayes
1997, p. 44; Hayes et al. 1997, p. 6). The impact of a drought on an
Oregon spotted frog population depends on the amount of complex marsh
habitat at a site, the availability of alternative breeding and rearing
areas, and the abundance of aquatic predators (Pearl 1999, p. 15).
Low water levels resulting from drought may reduce populations of
nonnative predators (fish and bullfrogs); however, both Hayes (1997, p.
43) and Pearl (1999, pp. 17-18) hypothesized that low water conditions
will increase the overlap between Oregon spotted frogs and nonnative
predators, such as brook trout and bullfrogs, by concentrating tadpoles
and froglets in the only available habitat. Such increased overlap is
expected to increase predation losses of Oregon spotted frogs (Pearl et
al. 2004, pp. 17-18). Several seasons of low water are expected to
cause local population extirpations of Oregon spotted frogs,
particularly where a small isolated population occupies a limited marsh
habitat that has a high abundance of aquatic predators (Pearl 1999, p.
15). Low water in breeding habitat will also expose eggs to increased
ultraviolet radiation and higher mortality
[[Page 51671]]
associated with pathogens (Kiesecker et al. 2001a, p. 682) (see
``Disease'' under Factor C section). Since 1960, the Klamath Basin has
had 8 of the 10 lowest inflows for Upper Klamath Lake between 1991 and
2009 (USFWS 2011a, p. 25). This has resulted in poor water quality and
reduced Oregon spotted frog reproduction due to desiccation of egg
masses (BLM and USFS multiple data sources). In addition, 5 of the 10
sites in the Klamath Basin are vulnerable to water management practices
that are timed such that the seasonal life-history needs of the Oregon
spotted frog are not met.
Although the Chemult Ranger District, Fremont-Winema National
Forest, in Klamath County, Oregon, documented high numbers of egg
masses at Jack Creek in 1999 and 2000 (335 and 320 respectively)
(Forbes and Peterson 1999, p. 6), drought conditions impacted the
Oregon spotted frog populations in subsequent years. The drought
occurred during the time period in which the Oregon spotted frog
population dramatically declined at Jack Creek (Gervais 2011, p. 15).
In 2001, those conditions restricted Oregon spotted frog breeding to
three small, disjunct areas representing less than 25 percent of their
typical habitat. Although there were sufficient water depths in the
breeding pools in 2002, only 17 percent of historical egg mass numbers
were detected, and 50 percent of the eggs did not hatch compared to the
68 to 74 percent hatch rates documented by Licht (1974, p. 618). The
impacts of the drought were further complicated when Oregon spotted
frog habitat was impacted by algal blooms, poor water quality, loss of
protective habitat, and alteration of the bank condition (USDA 2009a,
pp. 31, 33-34). By 2011, only 1 percent of historical egg mass numbers
were documented at this site.
Loss of Beaver--The American beaver (Castor canadensis) creates a
complex mosaic of aquatic habitat types that provides the seasonal
habitat needs of the Oregon spotted frog. Water impoundments created
and engineered by beavers result in a water storage reservoir that
raises the water table, reduces downstream erosion, lessens flood
events (unless the dam is breached), holds water year round, and
maintains stream flow during dry periods. Specifically, silt-filled
abandoned ponds become shallow wetlands and beaver meadows, which have
characteristics ideal for egg-laying. Beaver-maintained ponds retain
deeper waters important for summer foraging and growth of metamorphosed
frogs, and these ponds also provide overwintering habitat. When hypoxic
conditions occur in the wetlands and ponds, the frogs can move to the
more oxygenated waters of the associated creek, where they use
microhabitat features created by beavers such as large woody debris and
bank tunnels (Hallock and Pearson 2001, pp. 9-12; Shovlain 2005, p.
10).
Comparisons of beaver-occupied and not occupied watersheds in
Montana in relation to Columbia spotted frog populations found: (a)
Beaver watersheds had four times as many lentic and breeding sites as
non-beaver watersheds; (b) frog breeding sites were dispersed within
beaver drainages, while non-beaver watersheds often had only one frog
breeding site; (c) frog breeding sites were evenly distributed across
the elevational gradient in beaver watersheds, while they were centered
above the watershed midpoint in non-beaver watersheds; (d) frog
breeding sites were more dispersed within drainages with evidence of
beaver presence than would be expected given the configuration of the
underlying lentic habitat and have persisted despite being separated by
distances larger than the frog's dispersal ability; (e) beaver
watersheds with an average distance of less than 3.1 mi (5 km) between
breeding sites showed higher levels of connectivity than did non-beaver
watersheds with an average distance of more than 3.1 mi (5 km) between
breeding sites; and (f) short beaver watersheds had lower levels of
genetic divergence between breeding sites than those in long non-beaver
watersheds separated by the same distance, even when distances were
within the commonly observed dispersal ability of the frogs (Amish
2006, entire). Columbia and Oregon spotted frogs were separated into
two separate species (Rana pretiosa (Oregon spotted frog) and Rana
luteiventris (Columbia spotted frog)), based on genetic analysis (Green
et al. 1996, 1997). They are closely related species and likely evolved
in a similar way, with beavers playing a vital role in how frogs are
distributed within a watershed.
By 1900, beavers had been nearly extirpated in the continental
United States (Baker and Hill 2003, p. 288). Beavers have made a
remarkable comeback in many areas through natural recolonization and
relocation efforts (ODFW 2012, p. 1); however, their role as ecological
engineers is still severely curtailed region-wide, particularly within
human-populated areas, because they are often considered a pest species
because they can flood roads and property and destroy trees that are
valued by landowners (Baker and Hill 2003, p. 301). In at least one
site, a significant Oregon spotted frog decline was attributed to the
removal of a series of beaver dams that resulted in water loss within
some of the breeding areas leading to high embryo mortality attributed
to stranding (Hayes et al. 2000, p. 2). In Trout Lake Creek in
Washington, the loss of a beaver dam to a natural flood event resulted
in a significant decline (117 egg masses in 2001 to 0 in 2012) in
Oregon spotted frog reproduction (Hallock 2012, p. 33). Lack of beavers
within a watershed has been determined by USFS and BLM to be a threat
to maintenance of Oregon spotted frog habitat, and these agencies have
identified the Williamson, Upper Klamath Lake, and Upper Klamath sub-
basins for reintroduction of beaver to aid Oregon spotted frogs.
The States of Washington and Oregon allow lethal removal of beavers
and their dams. Under Washington State law, the beaver is classified as
a furbearer (WAC 232-12-007). The owner, the owner's immediate family,
an employee, or a tenant of property may shoot or trap a beaver on that
property if a threat to crops exists (RCW 77.36.030). In such cases, no
special trapping permit is necessary for the use of live traps.
However, a special trapping permit is required for the use of all traps
other than live traps (RCW 77.15.192, 77.15.194; WAC 232-12-142). It is
unlawful to release a beaver anywhere within Washington, other than on
the property where it was legally trapped, without a permit to do so
(RCW 77.15.250; WAC 232-12-271). To remove or modify a beaver dam, one
must have a Hydraulic Project Approval--a permit issued by Washington
Department of Fish and Wildlife (WDFW) for work that will use,
obstruct, change, or divert the bed or flow of State waters (RCW
77.55). Beavers are present to a varying degree within all Oregon
spotted frog occupied sub-basins in Washington and are maintaining
breeding habitats in some areas within the South Fork Nooksack River,
Black River, White Salmon River, and Middle Klickitat River sub-basins.
Active removal of beavers or their dams is occurring in at least the
South Fork Nooksack River, Black River, and Middle Klickitat River sub-
basins and may be occurring in the other occupied sub-basins in
Washington.
Beavers on public lands in Oregon are classified as Protected
Furbearers by Oregon Revised Statute (ORS) 496.004 and Oregon
Administrative Rule (OAR) 635-050-0050. A trapping license and open
season are required to trap beavers on public lands. Beavers on private
lands are defined as a Predatory Animal (ORS 610.002) and private
landowners
[[Page 51672]]
or their agents may lethally remove beavers without a permit from the
Oregon Department of Fish and Wildlife (ODFW). Currently, the presence
of beavers results in active maintenance of Oregon spotted frog habitat
in the Little Deschutes River, Upper Deschutes River, Middle Fork
Willamette River, Williamson River, and Upper Klamath Lake sub-basins.
Active removal of beavers and their dams can occur in the Oregon
spotted frog habitat in all of these occupied sub-basins in Oregon.
Under State laws in both Washington and Oregon, it is lawful to kill
beavers or to remove or modify beaver dams, and those lawful actions
reduce or degrade wetland habitats used by all life stages of Oregon
spotted frogs.
Hydrologic Changes Conclusion--A variety of factors affecting the
hydrology of wetlands and riverine systems cause the loss or
detrimental modification of habitats necessary for the survival and
reproduction of Oregon spotted frogs. Within 11 of the 15 sub-basins
occupied by the species, water diversions/manipulations, development,
drought, and loss of beavers are resulting in hydrological changes that
pose a threat to all life stages of the Oregon spotted frog, including
loss of or disconnections between breeding, rearing, and overwintering
habitat, as well as desiccation or flooding of egg masses. The impact
to Oregon spotted frogs of these hydrological changes has been
determined--based on our unified threats classification system (Threats
Synthesis Rangewide Analysis)--to be moderate to very high in five of
the occupied sub-basins: Middle Klickitat River, Upper Deschutes River,
Little Deschutes River, Williamson River, and Upper Klamath.
Changes in Vegetation
Oregon spotted frog egg-laying sites are generally characterized by
low vegetation canopy coverage and a substrate at least partially
covered with the previous year's emergent herbaceous vegetation
(Leonard 1997, p. 3; Hayes et al. 2000, p. 8; Pearl and Bury 2000, p.
6; Pearl 1999, p. 15). Egg masses are generally found in shallow water
over vegetation and are rarely found above open soil or rocky
substrates (Hayes et al. 2000, p. 8, Pearl and Bury 2000, p. 8). Watson
et al. (2003, p. 296) found that habitat selection by Oregon spotted
frogs during the breeding season was strongly correlated with sedge
habitat in Washington. In Oregon, Pearl et al. (2009a, p.141) found the
dominant vegetation at egg-laying areas to be sedge-rush habitat.
Loss of natural wetland and riverine disturbance processes as a
result of human activities has caused, and continues to cause,
degradation of Oregon spotted frog habitat. Historically, a number of
natural forces created emergent wetlands favorable to Oregon spotted
frogs. These forces included rivers meandering over their floodplains,
removing trees and shrubs and baring patches of mineral soil; beavers
felling trees and woody shrubs, trampling vegetation, and dragging
limbs and logs through shallows; and summer fires burning areas that
would be shallow water wetlands during the Oregon spotted frog breeding
season the following spring. Today, all of these forces are greatly
reduced, impaired, or have been permanently altered as a result of
human activities. In addition, the current wetland management paradigm
is generally a no-management approach that often results in continued
invasion by invasive plants or succession to a tree- and shrub-
dominated community, both of which are unsuitable for Oregon spotted
frog breeding.
Invasive plants such as reed canarygrass may completely change the
structure of wetland environments, and can create dense areas of
vegetation unsuitable as Oregon spotted frog habitat (McAllister and
Leonard 1997, p. 23). Reed canarygrass competitively excludes other
native plant species and limits the biological and habitat diversity of
host wetland and riparian habitats (Antieau 1998, p. 2). Reed
canarygrass also removes large quantities of water through
evapotranspiration, potentially affecting shallow groundwater
hydrologic characteristics (Antieau 1998, p. 2). Reed canarygrass
dominates large areas of Oregon spotted frog habitat at lower
elevations (Hayes 1997, p. 44; Hayes et al. 1997, p. 6) and is
broadening its range to high-elevation (i.e., above 4,500 feet (>1,371
m)) Oregon spotted frog habitat in the Little Deschutes and Upper
Deschutes River sub-basins in Oregon (USDA 2008, USDA 2009b, USDA
2009c, and USDA 2011b). Watson et al. (2003, p. 296) compared the types
and amount of habitat used by Oregon spotted frogs and found the frogs
used areas of reed canarygrass less frequently than other habitats
based on availability. Given this apparent avoidance of reed
canarygrass, vegetation shifts to reed canarygrass dominance in
wetlands occupied by Oregon spotted frogs are likely affecting Oregon
spotted frog breeding behavior.
Studies conducted in Washington (White 2002, pp. 45-46; Pearl and
Hayes 2004, pp. 22-23) demonstrated that the quality of breeding
habitats for Oregon spotted frogs is improved by reducing the height of
the previous years' emergent vegetation (i.e., reed canarygrass in
these cases). However, improvement in breeding habitat for Oregon
spotted frogs was retained only if vegetation management was
maintained. For example, in all occupied sub-basins in Washington and
in the Klamath sub-basin in Oregon, an indirect effect of the removal
of cattle grazing has been the reduction in the amount and quality of
breeding and rearing habitat due to encroachment by vegetation, such as
reed canarygrass and shrubs. The effects of grazing vary among sites
and likely depend on a suite of factors including, but not limited to,
timing, intensity, duration, and how these factors interact with
seasonal habitat use patterns of Oregon spotted frog.
Reed canarygrass is present at three of the British Columbia
breeding areas and is the dominant vegetation at most of the breeding
areas in Washington. In Oregon, reed canarygrass is colonizing portions
of Big Marsh and Little Lava Lake, both of which are headwaters to the
Little Deschutes and Upper Deschutes River sub-basins, respectively.
Reed canarygrass also is present in Oregon spotted frog habitat at Lava
Lake, Davis Lake, Wickiup Reservoir, multiple sites along the Little
Deschutes River (i.e., 7 out of 13 surveyed sites), Slough Camp, Wood
River Wetland, the Klamath Marsh NWR, Fourmile Creek, and the
Williamson River. The impact to Oregon spotted frogs due to habitat
loss from reed canarygrass invasion has been determined through our
threat analyses to be high to very high in seven sub-basins: Lower
Fraser River in British Columbia and all sub-basins in Washington. The
effects of reed canarygrass to Oregon spotted frog habitat are
considered to be moderate in two sub-basins in Oregon: Little Deschutes
River and Upper Deschutes River.
Vegetation succession was indicated as a negative factor at almost
all remaining Oregon spotted frog sites analyzed by Hayes, who noted
that some sites were particularly vulnerable to habitat loss where
marsh-to-meadow changes were occurring (Hayes 1997, p. 45). Pearl
(1999, p. 15) suggested that the aquatic habitat types necessary for
Oregon spotted frog reproductive sites in lake basins exist only within
a narrow successional window. As marsh size decreases due to plant
succession, shallow warm water sites required by Oregon spotted frogs
are lost to increased shading by woody vegetation (Pearl 1999, pp. 15-
16). Investigations by Hayes (1997, p. 45) and Pearl (1999,
[[Page 51673]]
p. 16) ranked 22 of 28 Oregon spotted frog sites as having a moderate
or high threat from vegetation succession. Encroachment around and into
marshes by lodgepole pine and other woody vegetation is occurring at
Conboy Lake in Washington (Ludwig 2011, p. 3) and at multiple breeding
locations in Oregon, and is likely facilitated by ditching and draining
of wetter sites to improve grazing (Cushman and Pearl 2007, p. 17). The
highest impact to Oregon spotted frogs resulting from lodgepole pine
encroachment is taking place in the Upper Deschutes River sub-basin and
in the upper elevations of the Little Deschutes River sub-basin in
Oregon, where these breeding habitats (i.e., those within the riparian
lodgepole plant association group), evolved with fire as a natural
disturbance process. The loss of natural fire cycles in forests of the
eastern Cascade Mountains due to suppression on National Forest land
since 1910 (Agee 1993, p. 58) has allowed succession to continue
without disturbance. Plot data suggest that historical fire return
intervals for riparian lodgepole pine vegetation types in central
Oregon ranged from 12 to 36 years and averaged 24 years (Simpson 2007,
p. 9-6), indicating that this disturbance process was more frequent
historically in this forest type.
The United States Department of Agriculture's Natural Resources
Conservation Service (NRCS) and Farm Service Agency have several
voluntary programs, including the Wetland Reserve Program (WRP), CREP,
and Wildlife Habitat Incentive Program. The WRP and CREP are voluntary
programs designed to help landowners address concerns regarding the use
of natural resources and promote landowner conservation. Under the WRP,
landowners enter into a voluntary agreement with NRCS to protect,
restore, and enhance wetlands on their property. Various enrollment
options are available to landowners, including Permanent Easements, 30-
Year Easements, Restoration Cost-Share Agreements, or 30-Year Contracts
(USDA NRCS 2013). Under the CREP, the Farm Service Agency provides
payments to landowners who sign a contract committing to keeping lands
out of agricultural production for a period of 10 to 15 years. NRCS
produces technical guidelines generally aimed at improving soil
conditions, agricultural productivity, and water quality, which
generally do not result in specific conservation measures for the
protection of the Oregon spotted frog. Rather, restoration actions
funded or carried out by NRCS include planting trees and shrubs in
riparian areas.
These activities have had unforeseen consequences to Oregon spotted
frog habitat by degrading breeding habitat because, as discussed above,
tree- and shrub-dominated communities are unsuitable for Oregon spotted
frog breeding. This is known to have occurred within the last 10 years
at breeding locations in Black, Samish, and South Fork Nooksack Rivers
in Washington (Nisqually NWR; Bohannon et al. 2012) and may be
happening elsewhere. Currently, one known occupied private land parcel
has entered into a WRP agreement in the Klamath Basin in Oregon. The
WRP agreement for this particular parcel allows no grazing in
perpetuity, which, in the long term, may result in reduced quality of
Oregon spotted frog habitat. We are aware of at least one CREP contract
in the South Fork Nooksack River sub-basin that resulted in conifer
tree plantings in Oregon spotted frog breeding locations, which
resulted in the wetted areas becoming drier and mostly shaded. The
Service has had preliminary discussions with NRCS and is working with
the agency to address this management issue.
Changes in vegetation conclusion--Expansion of reed canarygrass
into Oregon spotted frog habitat poses a threat to the continued
existence of these habitats given the invasive nature of the plant and
its ability to outcompete native vegetation in wetland habitats.
Shallow water wetlands inhabited by Oregon spotted frog are threatened
through rapid encroachment of the grass and increased
evapotranspiration of water. Loss of habitat at breeding sites due to
reed canarygrass is high to very high in seven occupied sub-basins in
British Columbia and Washington. Reed canarygrass poses a threat in the
Little Deschutes and Upper Deschutes River sub-basins in Oregon, and is
present at varying abundances in many locations occupied by Oregon
spotted frog.
Vegetation succession, particularly where natural disturbance
processes are lacking, is a negative factor at almost all Oregon
spotted frog sites. Structural changes to vegetation that occur through
succession, whether from native or nonnative grasses, shrubs, or trees,
results in decreased wetland size and amount of open water area
available to frogs. Furthermore, shrub and tree encroachment increases
shading of shallow warm water sites required by Oregon spotted frogs
for breeding and rearing. Encroachment by lodgepole pine and other
woody vegetation is occurring at multiple breeding locations in
Washington and Oregon and is considered a threat in at least seven sub-
basins: Lower Deschutes River, Upper Deschutes River, McKenzie River,
Middle Fork Willamette River, Williamson River, Upper Klamath Lake, and
Upper Klamath. Unintended loss of habitat is taking place as a result
of riparian restoration activities that remove grazing and plant shrubs
and trees within sub-basins occupied by Oregon spotted frogs in
Washington and Oregon. Therefore, based on the best scientific
information available, changes in vegetation pose a threat to Oregon
spotted frogs due to habitat loss and modification throughout the range
of the species.
Development
Removal or alteration of natural riparian vegetation around
watercourses or wetlands for urban or agricultural development
compromises aquatic ecosystem function via reductions in biodiversity
and water quality and quantity. Residential and commercial encroachment
often destroys or disturbs natural vegetation, alters water flows and
seasonal flooding, or results in the loss of entire wetland complexes.
Agricultural practices, including grazing, can result in the rapid
removal of water across the landscape for stimulation of early grass
production. All of these factors have been shown to reduce the survival
and reproductive capacity of Oregon spotted frogs, as discussed
previously.
Although the historical impact of development has significantly
reduced the abundance and geographic distributions of Oregon spotted
frogs (for example, the Fraser River Valley in British Columbia, Puget
Trough in Washington, and Willamette Valley in Oregon), development is
currently an ongoing threat at only a few specific locations. In
British Columbia, housing and residential developments continue to
remove or alter habitat at Mountain and Maria Sloughs, and there are
new commercial developments at Mountain Slough (COSFRT 2012, p. 26).
In Washington, some counties prohibit draining of wetlands and some
counties require setbacks from wetlands (see Factor D for further
information), but this is not consistent, nor consistently implemented.
In addition, a large proportion of the breeding areas for Oregon
spotted frogs in Washington is not technically classified as a wetland
under the county definitions because these areas are seasonally flooded
pastures. The private lands surrounding breeding areas for the Oregon
spotted frog in most of the occupied sub-basins are presently zoned as
rural or rural
[[Page 51674]]
residential, which is designed only to allow low-density housing and
maintain the rural and agricultural uses. However, the human
populations of all counties in the Puget Sound area are growing and
Thurston, Whatcom, and Skagit Counties have the 6th, 9th, and 10th
largest populations, respectively, among Washington State's 39 counties
(U.S. Census Bureau data downloaded August 29, 2012). Between 1990 and
2011, the populations in these three counties have doubled. This
population increase is expected to continue, resulting in new
residential and commercial developments that are likely to alter
vegetation, water flow, and the seasonal flooding that creates and
maintains habitat for Oregon spotted frogs.
Development of land along the Little Deschutes River and its
tributaries in Oregon is a continued threat to the Oregon spotted frog
due to loss or modification of its habitat. The rural character of the
Little Deschutes River watershed, the attractive location of private
property on the Little Deschutes River, and relatively inexpensive land
prices have contributed to a rapidly growing population (UDWC 2002, p.
12). In the 1960s and 1970s before Oregon Statewide planning regulated
growth and development, 15,000 one- and two-acre lots were created in
subdivisions in the vicinity of the Little Deschutes River. Since 1989,
Deschutes County has been the fastest growing county in Oregon on a
percentage basis. The unincorporated areas of Deschutes County,
including the lower portions of the Little Deschutes River, are
projected to increase in population size by as much as 56 percent above
the 2000 level over the next 20 years (UDWC 2002, p. 12). This rapid
population growth rate is expected to continue into the future (UDWC
2002, p. 12), thereby increasing risks to wetland habitats that support
Oregon spotted frogs in the vicinity of the Little Deschutes River.
Development in the Klamath Basin is also increasing in Oregon. The
population of Klamath County increased 10.5 percent from 1990 to 2000
(U.S. Census Bureau 2008) and annual housing starts have increased by
13 percent since 2000 (Portland State University 2011 Web site). Much
of the growth is outside of city boundaries, and several large
residential developments are within or adjacent to wetlands that
historically had the ability to support Oregon spotted frog habitat. In
addition, agricultural practices, including grazing, occur extensively
within all three occupied sub-basins. This has the potential to result
in the desiccation or inundation of Oregon spotted frog habitat (see
the ``Oregon'' discussion under ``Livestock Grazing,'' below). While it
is unknown to what extent urban development has impacted Oregon spotted
frog habitat, agricultural development is ongoing and continues to
impact Oregon spotted frog habitat.
Development conclusion--Development of residential, commercial, and
agricultural properties is continuing in at least 10 of the sub-basins
occupied by the Oregon spotted frog. In some areas, the human
population is expected to continue to grow. Development activities
directly and indirectly have removed or altered habitat necessary to
support all life stages of Oregon spotted frogs. Therefore, we consider
development--both at the present time and in the future--to be a threat
to the Oregon spotted frog due to loss or modification of its habitat.
Livestock Grazing
In several riparian zones and wetland complexes in British
Columbia, Washington, and Oregon, livestock grazing occurs within
Oregon spotted frog habitat, although its effects vary with the site
conditions, livestock numbers, timing, and intensity. Livestock
(primarily horses and cows) can cause direct mortality by trampling
adult frogs (Ross et al. 1999, p. 163) and egg masses when livestock
are allowed in shallow water habitat when frogs are present. Livestock
graze and trample emergent and riparian vegetation, compact soil in
riparian and upland areas, and reduce bank stability, which results in
increased sedimentation and water pollution via urine and feces (Hayes
1997, p. 44; Hayes 1998b, p. 8; 61 FR 25813). The resulting increases
in temperature and sediment production, alterations to stream
morphology, effects on prey organisms, and changes in water quality
negatively affect Oregon spotted frog habitat. Livestock trampling
compacts affected soils and decreases soil porosity, which results in
reduced water holding capacity (Kauffman and Krueger 1984, p. 434).
Livestock also act as vectors for the introduction of weed seeds that
alter riparian vegetation characteristics (Belsky and Gelbard 2000, p.
9), and they are a source of introduced parasites and pathogens (see
Factor C discussion).
Fourteen of twenty-eight (50 percent) sites surveyed in British
Columbia, Washington, and Oregon were directly or indirectly influenced
(negatively and positively) by livestock grazing (Hayes 1997, p. 44;
Hayes et al. 1997, p. 6; Pearl 1999, p. 16). Severe habitat
modification has been caused by cattle at several Oregon spotted frog
localities in Oregon. Large numbers of cattle at a site negatively
affect habitat for Oregon spotted frogs, particularly at springs used
by frogs as overwintering sites (Hayes 1997, p. 44). However, in recent
work monitoring the effects of livestock grazing on Oregon spotted
frogs in grazed and ungrazed treatments at Jack Creek on the Fremont
Winema National Forests in Oregon, Shovlain (2009, entire) suggested
that Oregon spotted frogs did not modify their habitat use in response
to increased grazing pressure in summer-time habitats. However,
Shovlain's analyses may have been affected by a relatively low sample
size and unbalanced data, the inability to account for frog habitat use
outside of the plots, as well as the possibility that the frog's
habitat use was related to the availability of water rather than
vegetation density or livestock effects (Shovlain 2009, pp. 11-12). In
summer-time habitat, livestock, in particular cattle, may increase
Oregon spotted frog's susceptibility to desiccation and trampling if
both frogs and livestock are using the same remnant pools. In addition,
cattle can impact the quantity of available water. A cow can drink 15
to 20 gallons of water per day (Engle 2002, cited in USDA 2004, p. 31).
For example, Jack Creek and its tributaries provide the only sustained
water to cow-calf pairs within the Jack Creek grazing allotment, and
the cows are on the allotment for about 100 days per year (USDA 2004,
p. 31). During drought years, such as 2000 through 2004 (see
``Drought'' discussion, above), the remnant pools, with the added
pressure of livestock, may dry up, resulting in frogs being stranded
and desiccating.
Moderate livestock grazing can, in some instances (for example,
Dempsey Creek in Washington), benefit Oregon spotted frogs by
maintaining openings in the vegetation in highly altered wetland
communities (Hayes 1997, p. 44; Hayes et al. 1997, p. 6; McAllister and
Leonard 1997, p. 25). Watson et al. (2003, p. 299) found that habitat
at 78 percent of the Oregon spotted frog locations surveyed at the
Dempsey Creek site had signs of grazing, which created penetrable, open
habitat that was otherwise too dense for frog use.
British Columbia--Only one known breeding location (Morris Valley)
in the Lower Fraser River sub-basin is grazed (by horses) (COSEWIC
2011, p. 33), and grazing is identified as a specific concern for
Oregon spotted frogs at this location because of the potential for
trampling of egg masses, bank erosion, and input of feces (COSEWIC
2011, p. 33).
Washington--In the recent past, it appears that grazing was
beneficial to
[[Page 51675]]
Oregon spotted frogs at all remaining breeding areas in Washington;
however, grazing no longer occurs in the breeding areas in four of the
six sub-basins due to land manager preferences and/or water quality
regulations that prohibit grazing within certain distances from rivers
and wetlands. Active management is required to maintain the Oregon
spotted frog habitat at these locations due to heavy reed canarygrass
infestations, but funding is limited and grazing had been the least
expensive and easiest management option. In the Black River, grazing
ceased along Dempsey Creek when the privately owned dairy operation was
sold. Cows were reintroduced to the Port Blakely Tree Farm and Musgrove
(Nisqually NWR) parcels in 2008 (USFWS 2011b), as part of a reed
canarygrass control experiment; however, Oregon spotted frog egg mass
numbers have not increased as was expected (WDFW 2011 database; USFWS
2011b). Grazing occurs at the only known breeding location in the Lower
Chilliwack River sub-basin. This site has likely persisted as a result
of dairy cows maintaining the site in a state of early seral habitat
(Bohannon et al. 2012, p. 17).
Oregon--Overgrazing of the Camas Prairie in Oregon was considered a
threat to Oregon spotted frog prior to 2008, after which grazing was
restricted (Corkran 2012). Overgrazing by cattle reduced the vegetative
hiding cover for frogs, making them more susceptible to predation.
Livestock-induced fertilization resulted in an increased density of the
aquatic vegetation, which inhibited the ability of frogs to drop below
the water's surface when threatened by predation while basking (Corkran
2012, pers. comm). However, grazing may be considered as a management
tool to maintain early seral habitat for Oregon spotted frogs in the
future if necessary (Corkran 2012, pers. comm).
None of the central Oregon Cascade breeding locations within the
Deschutes and Willamette National Forests is within grazing allotments.
Known breeding locations occur within allotments on the BLM Prineville
District lands along Crescent Creek, Long Prairie Creek, and the Little
Deschutes River. Currently, only the Crescent Creek area is affected by
active grazing on BLM lands, although there is potential for grazing to
occur on BLM lands along the Little Deschutes River. Grazing has been
cited as an impact to riparian and wetland habitats on private lands
along the Little Deschutes River (The Wetlands Conservancy, 2004, p.
22). Wetland habitats in the Little Deschutes River sub-basin have been
negatively impacted by grazing through removal of riparian vegetation,
which destabilizes banks and increases channel incision, resulting in
less water retention in riparian wetlands and conifer encroachment
(UDWC 2002, pp. 21 and 53).
Six sites in the Klamath Basin are associated with grazing: Jack
Creek, Buck Lake, Parsnip Lakes, and on private lands on the Wood
River, Williamson River, and adjacent to Klamath Marsh NWR. These sites
are potentially vulnerable to both the direct impacts of grazing
sedimentation, trampling, as well as the indirect effect of egg mass
desiccation resulting from water management techniques that drain water
early in frog breeding season to stimulate grass production. Livestock
grazing is cited as a specific concern for Oregon spotted frogs at Jack
Creek, Fremont-Winema National Forest, Chemult Ranger District, in
Oregon (USDA 2004, pp. 56-57). Since 1999, the population has reduced
from 670 breeding adults (335 egg masses) to 34 breeding adults (17 egg
masses) in 2011. The two primary breeding sites in Jack Creek occur on
private land that is heavily grazed in combination with USFS
allotments. This intensity of grazing is expected to have degraded the
quality of the Oregon spotted frog breeding habitat and reduced
reproduction (Shovlain 2005).
Since 2008, current USFS management at the Jack Creek site has not
permitted cattle grazing on lands occupied by Oregon spotted frogs
(Markus 2012, pers. comm.). However, 419 cow/calf pairs specifically
permitted for grazing have access to 61 ac (25 ha) of potential, but
not currently supporting, Oregon spotted frog habitat on this 68,349-ac
(27,660-ha) combination of USFS and private pasture. Within this
pasture, however, there are several riparian areas accessible to
grazing cattle as well as one offsite watering source installed on
adjacent private land. The permittee for this pasture has grazed their
private lands where Oregon spotted frogs are known to occur, although
the number of cattle and timing are not known. However, the permittee
has also partnered with the Service to complete multiple conservation
actions to benefit Oregon spotted frogs and their habitats on their
private lands including--but not limited to--the installation of 2 to 3
offsite watering sources, protection of frog ponds, thinning of
encroaching lodgepole pine trees, and installation of a wattle for
water retention (Markus 2012, pers. comm.).
Conflicts between cattle and frogs increase when stream flows are
limited, especially when cattle are using the creek for drinking
(Gervais 2011, p. 15). Between 2001 and 2005, and again in 2007,
drought conditions affected habitat for Oregon spotted frogs in the
Chemult Ranger District, Fremont-Winema National Forest in Oregon.
However, until 2008, when grazing was restricted, 419 cow/calf pairs
had access to the habitat areas associated with Oregon spotted frogs
(Gervais 2011, p. 11). Cattle were observed congregating in Oregon
spotted frog habitat because nearly every other water source in the
allotment went dry (Simpson 2002, pers. comm.). Trampling of frogs by
cattle and alterations in water quality, bank structure, and loss of
protective vegetation compounded the impacts of the reduction of
available habitat due to drought conditions on Oregon spotted frog
reproduction (USDA 2009a, pp. 31, 33-34).
Livestock Grazing Conclusion--Where livestock grazing coincides
with Oregon spotted frog habitat, impacts to the species include
trampling of frogs and changes in habitat quality due to increased
sedimentation, increased water temperatures, water management
techniques, and reduced water quality. The effects of livestock grazing
vary with site conditions, livestock numbers, and timing and intensity
of grazing. In Washington, all of the known occupied areas have been
grazed in the recent past, but where grazing has been removed, heavy
infestations by invasive reed canarygrass have reduced or eliminated
habitat for Oregon spotted frogs unless other management techniques
were applied. In controlled circumstances, moderate grazing can be
beneficial if it is the only practical method for controlling invasive,
nonnative vegetation and sustaining short vegetation characteristics
needed for egg laying. Grazing is ongoing in 10 of the occupied sub-
basins and is considered to be a threat to Oregon spotted frogs at
these locations.
Conservation Efforts To Reduce Habitat Destruction, Modification, or
Curtailment of Its Range
British Columbia--Past and ongoing habitat conservation activities
in British Columbia include habitat creation at MD Aldergrove, Maria
Slough, and Mountain Slough; habitat rehabilitation at Maria and
Mountain Sloughs; and invasive grass species management at MD
Aldergrove, Maria Slough, and Mountain Slough. There also is a
landowner stewardship contact program that encourages stewardship
activities at Mountain Slough. However, the Service concluded that
these measures are not sufficient to ameliorate threats to
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Oregon spotted frogs in the Lower Fraser River.
Washington--In Washington, some reed canarygrass management is
taking place at most of the breeding locations in the Black River, on
the Trout Lake NAP, and at Conboy Lake NWR. These management techniques
include mowing, burning, cattle grazing, and shade cloth. However,
these management techniques are not widespread at any one location or
adequate to prevent loss of egg-laying habitat.
Conboy Lake NWR in Washington has completed several wetland
restoration projects to restore natural hydrological processes to
portions of the refuge. This enabled the NWR to maintain independent
water management of several wetlands, regardless of the water-related
impacts of local landowners. However, under current management, water
is not retained throughout the year on most of the NWR and adjacent
private wetlands, and many of these areas that had Oregon spotted frogs
in the late 1990s no longer have Oregon spotted frogs.
Cattle grazing ceased at Trout Lake NAP in Washington after a
monitoring study showed no apparent positive effect on the Oregon
spotted frog population trends (Wilderman and Hallock 2004, p. 10),
indicating either that grazing was not an effective tool for reed
canarygrass management at this location, or that perhaps reed
canarygrass was not as threatening to breeding frogs at this location
as previously thought. This may be because winter snow pack flattens
the reed canarygrass, creating a mostly sun-exposed water surface
available to Oregon spotted frogs during the breeding season. The
observed negative consequences of grazing, while perhaps acceptable if
there was clear benefit to the Oregon spotted frog populations, were
not compatible with other site management goals and posed a limitation
to future restoration on the site (Wilderman and Hallock 2004, p. 14).
Instead, problematic areas of reed canarygrass are being managed using
ground barriers and occasional fall mowing (Hallock 2012, p. 31).
Under the Washington State Forest Practices Act, Washington
Department of Natural Resources (WDNR) must approve certain activities
related to growing, harvesting, or processing timber on all local
government, State, and privately owned forest lands. WDNR's mission is
to protect public resources while maintaining a viable timber industry.
The primary goal of the forest practices rules is to achieve protection
of water quality, fish and wildlife habitat, and capital improvements
while ensuring that harvested areas are reforested. Presently, the
Washington State Forest Practices Rules do not specifically protect
Oregon spotted frogs; however, they do include protection measures for
surface waters and wetlands. The intent of the protection measures,
such as buffers on wetlands, is to limit excess coarse and fine
sediment delivery and to maintain hydrologic regimes. Tree harvest is
limited in wetland buffers, which may in turn facilitate vegetation
encroachment. Landowners have the option to develop a management plan
for the species if it resides on their property, or if landowners
choose not to develop a management plan for the species with WDFW,
their forest practices application will be conditioned to protect this
public resource. While the Washington State Forest Practices Rules
provide some protections for the Oregon spotted frog and its habitat,
the direct and indirect consequences of limiting tree harvest within
the wetland buffer is vegetation encroachment that is resulting in loss
of wetlands (i.e., reduced size) and shading.
NRCS is overseeing the restoration at two Samish River locations
and is incorporating Oregon spotted frog breeding habitat requirements
into its planned restoration (that originally included de-leveling and
tree and shrub plantings in the breeding areas) (Bohannan et al. 2012,
p. 17).
Oregon--In Oregon, several conservation actions have been and
continue to be implemented for Oregon spotted frogs in the Deschutes
River Basin. Sunriver Nature Center has been monitoring the frog
population at the Sunriver Resort since 2000. Although this area is
affected by the fluctuating flows out of Wickiup Reservoir, Sunriver
Nature Center has constructed weirs that allow the water level to be
steady or rising from the time of egg-laying through hatching, thus
assisting the persistence of this large and stable population. The
Deschutes National Forest has closed perimeter ditches at Big Marsh,
where past drainage and grazing had led to degradation of the marsh.
The Mt. Hood National Forest has fenced sections of Camas Prairie and
restricted excessive grazing of the meadow. Implementation of these
conservation actions is expected to improve breeding success of Oregon
spotted frogs at these locations, but data confirming this hypothesis
are not yet available. In addition, BLM's Prineville District Office
recently completed encroachment removal projects and repairs to
headcuts in systems that have had historically or currently have Oregon
spotted frogs. Headcutting is a process of active erosion in a channel
caused by an abrupt change in slope. Turbulence in the water undercuts
substrate material resulting in collapse of the upper level. This
under-cut-collapse process advances up the stream channel. The results
of BLM's efforts are unknown at this time; however, they were completed
specifically to ameliorate threats to Oregon spotted frog habitat.
Since 1994, in the Oregon portion of the Klamath Basin, the
Service's Partners for Fish and Wildlife Program, in collaboration with
private landowners, has restored approximately 8,832 ac (3,568 ha) of
wetlands adjacent to Upper Klamath Lake. Several habitat restoration
projects are underway in known occupied areas including Crane Creek,
Sevenmile Creek, Jack Creek, and the Upper Williamson River.
Restoration projects include re-channelizing creeks and rivers to
provide breeding and rearing habitat, construction of breeding ponds,
construction of riparian fences to exclude cattle, and the installation
of alternate water sources. To date, Oregon spotted frogs have been
detected in only one restored, previously unoccupied wetland area,
although survey efforts in restored habitats have not yet been
completed.
The BLM's Klamath Falls Field Office has initiated several habitat
restoration projects within their Wood River Wetland property,
including installation of water control structures, construction of
breeding ponds, and canal restructuring for additional breeding areas.
To date, 3,000 ac (1,214 ha) of wetland habitats associated with the
Wood River Canal have been restored. However, for reasons unknown,
Oregon spotted frogs have not been detected in the restored wetlands,
but rather have only been associated with the canal system (BLM
multiple data sources). BLM actively manages the water in the canal
during the breeding season to prevent stranding and inundating Oregon
spotted frog egg masses.
The Fremont-Winema National Forest, Chemult Ranger District, in the
Oregon portion of the Klamath Basin has initiated a project to restore
habitat along Jack Creek, which as of 2008, includes the removal of
cattle from a portion of the lands owned by the USFS (Gervais 2011 p.
9). In addition, encroaching lodgepole pine (Gervais 2011 pp. 11-12)
has been thinned on both USFS and private lands as a result of this
project. In cooperation with adjacent private landowners, the USFS
recently released seven beavers into the
[[Page 51677]]
Jack Creek watershed (Simpson 2012, pers. comm.), which is intended to
increase the open water and breeding habitat for Oregon spotted frogs.
One of the private landowners has also installed log fences to protect
three Oregon spotted frog pools, and two off-stream water sources to
exclude cattle from riparian areas, and wattle installment (a
fabrication of poles interwoven with slender branches) for water
retention (Markus 2012, pers. comm.). In addition, in 2009, the USFS
installed fences at Buck Meadow to control grazing on the USFS lands
(Lerum 2012, p. 18). The long-term benefits of the USFS efforts are
unknown at this time; however, these actions were completed to
specifically ameliorate threats to the Oregon spotted frog's habitat.
The USFS has completed and continues to work on Oregon spotted frog
site management plans that identify threats and management actions to
reduce threats at each of the following sites: Sevenmile, Jack Creek,
Buck Lake, Dilman Meadow, Hosmer Lake, Lava and Little Lava Lake, Big
Marsh, Odell/Davis Lake, Little Cultus Lake, Mink Lake Basin, and Gold
Lake. Implementation of management actions is voluntary and dependent
upon funding, and will likely occur at the District level.
The comprehensive conservation plan (CCP) for Klamath Marsh NWR
includes conservation actions for maintaining or improving local
habitat conditions for the benefit of Oregon spotted frogs on NWR
property. These include: Restoring or maintaining hydrologic regimes,
protecting and restoring ephemeral and permanent wetlands, restoring or
maintaining open water and early seral vegetation communities,
reevaluating or discontinuing fish stocking practices, developing
comprehensive grazing strategies or adaptive management plans where
livestock occur in habitat, and working locally and cooperatively to
maintain and restore habitat conditions and to monitor the outcomes of
management actions for Oregon spotted frog (USFWS 2010a, p. 72). The
CCPs detail program planning levels that are sometimes substantially
above current budget allocations and are primarily used for strategic
planning and priority setting; thus inclusion of a project in a CCP
does not guarantee that the project will be implemented. However,
implementation of the above conservation actions within the CCP could
benefit a minimum of 338 breeding individuals. These actions are
expected to improve the status of the Oregon spotted frog on the
Klamath Marsh NWR if adequate budget allocations are provided and the
projects are implemented. Existing wetland restoration activities at
Klamath Marsh NWR have been limited to invasive weed management (Mauser
2012, pers. comm.).
Summary of habitat or range destruction, modification, or
curtailment--Past human actions have destroyed, modified, and curtailed
the range and habitat available for the Oregon spotted frog, which is
now absent from an estimated 76 to 90 percent of its former range. The
loss of wetlands is continuing at certain locations in at least 10 of
the 15 remaining occupied sub-basins, particularly on private lands.
The historical and ongoing alteration of hydrological processes
resulting from the operation of existing water diversions/manipulation
structures, existing and new roads, residential development,
agricultural areas, and the removal of beavers continues to impact
Oregon spotted frogs and their habitat. The changes in hydrology result
in the loss of breeding through inundation or desiccation of egg
masses, loss or degradation of habitat necessary for all Oregon spotted
frog life stages, and the creation of habitat conditions that support
nonnative predaceous species.
Reed canarygrass invasions, plant succession, and restoration
plantings continue to modify and reduce the amount and quality of
habitat necessary for all Oregon spotted frog life stages. The timing
and intensity of livestock grazing, or lack thereof, continues to
change the quality of Oregon spotted frog habitat in British Columbia,
Washington, and Oregon due to increased sedimentation, increased water
temperatures, and reduced water quality. Oregon spotted frogs in all
currently occupied sub-basins are subject to one or more of these
threats to their habitat. Eleven of the 15 occupied sub-basins are
currently experiencing a high to very high level of impact, primarily
due to hydrological changes/manipulations, vegetation encroachment, and
reed canarygrass invasions. These impacts are ongoing, are expected to
continue into the future, and affect habitat that supports all life
stages of the Oregon spotted frog.
The benefits of the conservation actions to Oregon spotted frogs
are site-specific, but are not sufficient to ameliorate the habitat
threats at a sub-basin scale. Wetland restoration efforts have been
implemented, but rarely are these specifically designed for Oregon
spotted frogs, and may inadvertently reduce habitat quality for this
emergent wetland-dependent species. Further, post-restoration
monitoring has not been accomplished to evaluate whether these efforts
are benefiting Oregon spotted frogs. Therefore, based on the best
information available, the threats to Oregon spotted frog from habitat
destruction, modification, or curtailment are occurring throughout the
entire range of the species, and are expected to continue into the
future.
Factor B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Overutilization for commercial, recreational, scientific, or
educational purposes has been documented for a wide range of
amphibians. During the egg-laying period, Oregon spotted frogs occur in
relatively easy-to-access locations that could make them easy to
collect. However, we are not aware of collection of Oregon spotted
frogs for commercial, recreational, or educational purposes.
Oregon spotted frog populations may be negatively impacted by
scientific studies. In all Washington breeding locations and some of
the breeding locations in British Columbia and Oregon, surveys are
conducted annually during the egg-laying period. While these surveys
are conducted in a manner to avoid trampling of frogs and egg masses
(protocol example Pearl et al. 2010), such impacts may still occur. The
extent to which any population is impacted by these surveys is unknown,
but expected to be low. Eggs were collected each year beginning in 2002
from at least two of the extant locations in British Columbia for a
headstart rearing program, which released metamorphic Oregon spotted
frogs back into those sites (COSFRT 2012, pp. 30-31). This effort has
ceased because it was deemed unsuccessful at bolstering the extant
populations; however, captive husbandry for potential release into new
locations continues.
The WDFW has collected 7,870 eggs (through 2011) from various
breeding locations on the Black River and Conboy Lake NWRs for their
captive-rearing program (Tirhi and Schmidt 2011, pp. 51-55). During
this period, the population has continued to decline at Conboy Lake,
but the source of the decline is unclear and cannot specifically be
attributed to the egg collection. The USGS and Colorado State
University have been collecting eggs in the Deschutes and Klamath
Basins for genetic studies since 2007, resulting in the collection of
at least 3,000 eggs (Robertson and Funk 2012 pp. 8-11; Pearl 2012,
pers. comm.). However, we have no evidence to indicate that Oregon
spotted frogs are being overutilized for commercial,
[[Page 51678]]
recreational, scientific, or educational purposes such that this
activity currently poses a threat to the species or is likely to in the
future.
Factor C. Disease or Predation
Disease
Amphibians are affected by a variety of diseases, and some diseases
are known to negatively affect declining amphibian species. Diseases
that are currently known to occur in Oregon spotted frogs and have the
potential to affect populations are briefly discussed below. The
specific effects of disease and parasitism on Oregon spotted frogs are
not well documented.
Red-Leg Syndrome--Red-leg syndrome has been identified in several
declining amphibian species but is not known to be a significant
problem for the Oregon spotted frog (Blaustein 1999, pers. comm.). Red-
leg syndrome refers to a common condition in which there is a reddening
of the lower body, usually the legs and sometimes the abdomen, due to a
dilation of capillaries under the skin. This disease is presumed to be
widespread, having been reported for >100 years in many different
species of frogs and salamanders in captivity and in the wild (Densmore
and Green 2007, p. 236).
Chytrid Fungus--Bd has been implicated in the decline and
extinction of numerous amphibian species in multiple locations around
the world (Speare and Berger 2004). In the United States, 7 families
including 18 amphibian species have been diagnosed as infected with Bd
(Speare and Berger 2004). Bd infection has been documented in at least
seven ranid frog species from the PNW, including Oregon spotted frogs
(Adams et al. 2010, p. 295; Pearl et al. 2009b, p. 212; Hayes et al.
2009, p. 149). Chytridiomycosis is a cutaneous infection that ``results
in a severe diffuse dermatitis characterized by epidermal hyperplasia,
hyperkeratosis, and variable degrees of cutaneous ulceration and
hyperemia'' (Bradley et al. 2002, p. 206). Clinical signs can include
lethargy, abnormal posture, loss of the righting reflex (ability to
turn over), and death (Daszak et al. 1999, p. 737). The fungal
organism, Bd, is likely transmitted by release of zoospores into the
water that eventually contact a susceptible animal, penetrating the
skin, and establishing an infection (Pessier et al. 1999, p. 198;
Bradley et al. 2002, p. 206). Dermal infections by Bd are thought to
cause mortality by interfering with skin functions, including
maintaining fluid and electrolyte homeostasis (balance), respiration,
and the skin's role as a barrier to toxic and infectious agents
(Pessier et al. 1999, p. 198; Bradley et al. 2002, p. 206). Unlike most
other vertebrates, amphibians drink water and absorb important salts
(electrolytes) through the skin rather than the mouth. In diseased
individuals, electrolyte transport across the epidermis was inhibited
by >50 percent, resulting in cardiac arrest and death (Voyles et al.
2009, pp. 582, 585).
In 2007 and 2008, the USGS sampled Oregon spotted frogs at sites
across Washington and Oregon; Bd was confirmed at all locations sampled
(Pearl et al. 2009b, p. 212). Even though Pearl et al. (2009b, p. 216)
detected Bd at 100 percent of the sites sampled, they did not observe
morbidity or mortality that could be attributed to chytridiomycosis. In
addition to confirmation at USGS-sampled sites, Bd has been confirmed
in Oregon spotted frogs near Sunriver in central Oregon (Bowerman 2005,
pers. comm.) and Conboy Lake NWR (Hayes et al. 2009, p. 149) in
Washington. Pearl et al. (2007, p. 147) detected Bd more frequently in
highly aquatic species, such as Oregon spotted frogs, than in species
with more terrestrial adult stages and shorter larval periods,
suggesting that Oregon spotted frogs may be experiencing elevated
exposure and infection due to their highly aquatic life-history. In
addition, modeling done by Pearl et al. (2009b, p. 213) indicates that
juvenile Oregon spotted frogs that test positive for Bd infection are
more likely to have a poorer body condition after overwintering than
individuals that test negative for Bd infection.
Alone, Bd may not be a concern for some healthy amphibian
populations; however, most of the Oregon spotted frog populations in
Oregon and Washington are already exposed to several stressors, such as
predation, competition from nonnative species, and water quality
degradation, and the effects of Bd are likely to be exacerbated and
potentially compounded by these interactions (for example, see Parris
and Baud 2004, pp. 346-347; Parris and Cornelius 2004, pp. 3388-3390;
Parris and Beaudoin 2004, p. 628). In addition, Bd has been found in
nonnative species that co-occur with Oregon spotted frogs in central
Oregon (Pearl et al. 2007, p. 147); in particular, bullfrogs may serve
as a Bd host while experiencing limited negative effects from the
pathogen (Daszak et al. 2004, p. 203).
Laboratory studies have shown that infecting Oregon spotted frogs
with Bd inhibits growth without necessarily showing any direct clinical
signs (Padgett-Flohr and Hayes 2011). Recently metamorphosed frogs
exposed to one of two strains of Bd tested positive for the pathogen
within 11 days after exposure; however, no frogs died or displayed
clinical signs of disease and most (83 percent) tested negative for the
pathogen within 90 days of exposure. However, infected frogs gained
significantly less weight than control animals, suggesting the
infection carried an energetic cost. The detection of Bd at all Oregon
spotted frog sites sampled, combined with the lack of observed
mortality (in the wild and laboratory testing), indicates Oregon
spotted frogs may be able to persist with Bd infections (Pearl et al.
2009b, p. 216) but growth and presumed long-term survival (e.g.,
avoidance of predators) are inhibited. Consequently, in light of the
numerous amphibian extinctions attributed to Bd, and in conjunction
with the other stressors that impact Oregon spotted frogs, we conclude
that Bd poses a risk to individual Oregon spotted frog populations,
particularly those most susceptible to climate changes (see Factor E
discussion), but additional studies are necessary to determine whether
Bd is a threat rangewide to the Oregon spotted frog.
Other pathogens, such as iridoviruses (specifically Ranavirus),
have been documented to cause mortality in North American amphibians
(Dasak et al. 1999, pp. 741-743). While not yet documented in wild
Oregon spotted frog populations, iridovirus outbreaks have been
identified as a major source of mortality in British Columbia captive-
rearing programs for Oregon spotted frogs (COSEWIC 2011, p. 35).
Saprolegnia--The oomycete water mold Saprolegnia has been suggested
as one of the causes of amphibian declines in the PNW (Kiesecker and
Blaustein 1997, p. 218). Genetic analysis confirmed oomycetes of
multiple genera on amphibian eggs in the PNW, including Oregon spotted
frogs (Petrisko et al. 2008, pp. 174-178). McAllister and Leonard
(1997, p. 25) reported destruction of developing Oregon spotted frog
egg masses by this fungus, but not to the extent observed in other
amphibian eggs. The threat of Saprolegnia to Oregon spotted frog
populations is unclear, but this fungus has been shown to destroy
Oregon spotted frog egg masses and could pose a threat to individual
Oregon spotted frog breeding areas in the future.
Ultraviolet-B Radiation--Impacts resulting from exposure to
ultraviolet-B (UV-B) radiation appear to vary greatly between amphibian
species. Ambient levels of UV-B radiation in the atmosphere have risen
significantly over the past few decades due to decreases in
stratospheric ozone, climate warming,
[[Page 51679]]
and lake acidification. Because amphibian eggs lack shells and adults
and tadpoles have thin, delicate skin, they are extremely vulnerable to
increased levels of UV-B radiation. However, the harmful effects of UV-
B radiation on amphibians depend upon a number of variables (Blaustein
et al. 2003, pp. 123-128). Studies summarized in Blaustein et al.
(2003) indicate UV-B exposure can result in mortality, as well as a
variety of sublethal effects, including behavior alteration, slow
growth and development, and developmental and physiological
malformations. The type and severity of effect varies by life stage
exposed and dosage of UV-B. Experimental tests conducted by Blaustein
et al. (1999, p. 1102) found the hatching success of Oregon spotted
frogs was unaffected by UV-B, indicating their eggs may be UV-
resistant. However, a meta-analysis of available published literature
conducted by Bancroft et al. (2008) found that exposure to UV-B
resulted in a 1.9-fold reduction in amphibian survival and that larvae
(tadpoles) were more susceptible than embryos. In addition, Bancroft et
al. (2008) determined that UV-B interacted synergistically with other
environmental stressors, such as contaminants, resulting in greater
than additive effects on survival. For example, Kiesecker and Blaustein
(1997, pp. 217-218) found increased mortality associated with the
fungus identified as Saprolegnia ferax in amphibian embryos exposed to
UV-B; especially susceptible were amphibians that lay eggs in communal
egg masses, like Oregon spotted frogs. At present, the extent of
population-level impacts from UV-B exposure is unknown.
Malformations--The North American Reporting Center for Amphibian
Malformations (NBII 2005) documents amphibian malformations throughout
the United States. Malformations of several Rana species, including the
Cascades frog (Rana cascadae), red-legged frog (Rana aurora), foothill
yellow-legged frog (Rana boylii), and bullfrog, have been reported
within the current and historical range of the Oregon spotted frog in
Washington, Oregon, and California. We are aware of one report from
Thurston County, Washington, of an Oregon spotted frog with an extra
forelimb (NBII 2005) and reports of malformations from Deschutes
(Johnson et al. 2002a, p. 157; Bowerman and Johnson 2003, pp. 142-144),
Douglas, and Lane (NBII 2005) Counties in Oregon. Based on research on
numerous amphibian species, including Oregon spotted frog, growing
evidence suggests that the high frequencies of severe limb
malformations may be caused by a parasitic infection (Ribeiroia
ondatrae) in amphibian larvae (Johnson et al. 2002a, p. 162). Recent
investigations also indicate small fish and certain libellulid and
corduliid dragonfly larvae attack developing tadpoles and can cause
high incidences of missing-limb deformities, including complete
amputation (Ballengee and Sessions 2009; Bowerman et al. 2010). At
present, the extent of population-level impacts from malformations
among Oregon spotted frogs is unknown.
Parasitic infection--Aquatic snails (Planorbella spp.) are the
exclusive intermediate host for the trematode Ribeiroia ondatrae
(Johnson and Chase 2004, p. 523) and are found in a diversity of
habitats, including ephemeral ponds, montane lakes, stock ponds,
oxbows, drainage canals, and reservoirs (Johnson et al. 2002a, p. 164).
Trematodes are parasitic flatworms that have a thick outer cuticle and
one or more suckers or hooks for attaching to host tissue. Johnson et
al. (2002a, p. 165) postulate that the dramatic and widespread
alterations of aquatic ecosystems, particularly the construction of
small impoundments or farm ponds, may have created environments that
facilitate high densities of Planorbella snails and the resulting
infections from R. ondatrae. Many of the sites with high frequencies of
malformations were impacted heavily by cattle and supported dense
Planorbella snail populations. Malformations in multiple amphibian
species were found in Washington ponds that had a history of grazing
that extended back at least 50 years (Johnson et al. 2002a, p. 165).
Johnson et al. (2002a, p. 166) found the frequency of malformations
in larval amphibians was significantly higher than in transformed
amphibians from the same system, suggesting that malformed larvae
experience greater mortality prior to and during metamorphosis.
However, sensitivity to and severity (mortality versus no malformation)
of infection varies by amphibian species (Johnson and Hartson 2009, p.
195) and tadpole stage exposed (Schotthoefer et al. 2003, p. 1148).
High levels of R. ondatrae infection and the resulting
malformations may increase mortality in wild amphibian populations and
may represent a threat to amphibian populations already in decline.
Johnson et al. (2002a, p. 157) and Bowerman and Johnson (2003, pp. 142-
144) have found deformities in Oregon spotted frogs caused by this
parasite at the Sunriver Nature Center Pond, which had a high
population of large planorbid snails. Three additional ponds within 6
mi (10 km) were also investigated, each of which supported planorbid
snails, but at lower infestation levels. None of these ponds yielded
malformed Oregon spotted frogs (Bowerman et al. 2003, pp. 142-143).
Most of the malformations found in anuran frogs were around the hind
limbs, where they are more likely to be debilitating (hinder mobility)
and expose the frog to increased risk of predation (reduced escape/
evade ability) (Johnson et al. 2002a, p. 162). In a study on wood frogs
(Rana sylvatica), Michel and Burke (2011) reported malformed tadpoles
were twice as vulnerable to predators because they could not escape or
evade.
Human manipulation of upland areas adjacent to amphibian breeding
areas and direct manipulation of the breeding areas can affect the
prevalence of Planorbella snails and the infection rate of R. ondatrae.
Complex habitats reduce transmission rates of larval trematodes because
these habitats provide more refugia for tadpoles. Alternatively,
simplified habitats, such as agricultural landscapes, have been shown
to reduce parasite prevalence by limiting access of vertebrate hosts,
particularly in birds (King et al. 2007, p. 2074). However, when
simplified habitats are subject to water runoff associated with
agricultural, cattle, or urban sources and eutrophication, the
abundance of snails can increase, thereby increasing the prevalence of
trematodes and parasitic risks to frogs (Johnson and Chase 2004, pp.
522-523; Johnson et al. 2007 p. 15782). While the effects of these
parasite-induced malformations are clear at the individual scale,
population-level effects remain largely uninvestigated. However, Biek
et al. (2002, p. 731) found that the viabilities of pond-breeding
amphibians were most vulnerable to reductions in juvenile or adult
survival relative to other portions of the life cycles. Therefore, it
is reasonable to infer that where Planorbella snails coincide with
Oregon spotted frogs, malformations will occur resulting in mortality
of juvenile frogs and a reduction in the viability of the Oregon
spotted frog population at that location. At present, it is not known
where these co-occurrences take place, or how extensive infections
levels may be, but 11 of the occupied sub-basins have agricultural,
cattle, or urban sources that produce runoff that can increase the
snail populations and negative effects have been demonstrated
[[Page 51680]]
at the Sunriver Nature Center Pond population.
Predation
Predation is a process of major importance in influencing the
distribution, abundance, and diversity of species in ecological
communities. Generally, predation leads to changes in both the
population size of the predator and that of the prey. In unfavorable
environments, prey species are stressed or living at low population
densities such that predation is likely to have negative effects on all
prey species, thus lowering species richness. In addition, when a
nonnative predator is introduced to the ecosystem, negative effects on
the prey population may be higher than those from co-evolved native
predators. The effects of predation may be magnified when populations
are small, and the disproportionate effect of predation on declining
populations has been shown to drive rare species even further toward
extinction (Woodworth 1999, pp. 74-75).
Introduced fish species within the historical range of the Oregon
spotted frog may have contributed to losses of populations. Oregon
spotted frogs, which are palatable to fish, did not evolve with these
introduced species and may not have the mechanisms to avoid the
predatory fish that prey on the tadpoles. The microhabitat requirement
of the Oregon spotted frog, unique among native ranids of the PNW,
exposes it to a number of introduced fish species (Hayes 1994, p. 25),
such as smallmouth bass (Micropterus dolomieu), largemouth bass
(Micropterus salmoides), pumpkinseed (Lepomis gibbosus), yellow perch
(Perca flavescens), bluegill (Lepomis macrochirus), brown bullhead
(Ameriurus nebulosus), black crappie (Pomoxis nigromaculatus), warmouth
(Lepomis gulosus), brook trout (Salvelinus fontinalis), rainbow trout
(Oncorhynchus mykiss), fathead minnow (Pimephales promelas) (Hayes and
Jennings 1986, pp. 494-496; Hayes 1997, pp. 42-43; Hayes et al. 1997;
McAllister and Leonard 1997, p. 14; Engler 1999, pers. comm.), and
mosquitofish (Gambusia affinis) (Wydoski and Whitney 2003, p. 163;
Johnson 2008, p. 5).
Surveys from 1993 to 1997 in British Columbia, Washington, and
Oregon documented at least one introduced predator in 20 of 24 sites
(Hayes et al. 1997, p. 5). Brook trout was the most frequently recorded
introduced predator, which was recorded at 18 of 24 sites. Although
differences in temperature requirements between the two species may
limit their interactions, brook trout apparently occur with the Oregon
spotted frog at cold-water springs, where the latter species probably
overwinters and where cooler water is favorable to brook trout (Hayes
et al. 1997, p. 5). During drought years, dropping water levels result
in overlap in habitat use between these two species. As wetland refuges
are reduced, Oregon spotted frogs become concentrated and the larval
stages are exposed to brook trout predation (Hayes et al. 1997, p. 5;
Hayes 1998a, p. 15), resulting in lower Oregon spotted frog recruitment
(Pearl 1999, p. 18). In addition to effects in breeding habitat, Pearl
et al. (2009a, p. 143) found substantial evidence for a negative effect
on overwintering Oregon spotted frogs from nonnative fish with access
to spring and channel habitats. In these latter situations, predation
is believed to be more pronounced in spatially constrained
overwintering habitats where frogs and fish may both seek flowing water
with dissolved oxygen. Their findings suggest that these negative
effects are mediated by habitat complexity and the seasonal use of
microhabitats, and Oregon spotted frogs can benefit from fish-free
overwintering sites, even if fish are present in other local habitats.
Demographic data indicate that sites with significant numbers of
brook trout and/or fathead minnow have a skewed ratio of older spotted
frogs to juvenile frogs, suggesting poor reproductive success or
juvenile recruitment (Hayes 1997, pp. 42-43, 1998a). While experimental
data are sparse, field surveys involving other western amphibians
(e.g., Adams 1999, p. 1168; Monello and Wright 1999, pp. 299-300; Bull
and Marx 2002, pp. 245-247; Vredenberg 2004; Knapp 2005, pp. 275-276;
Pearl et al. 2005b, pp. 82-83; Rowe and Garcia 2014, pp. 146-147) and
other closely related frog species strongly suggest that introduced
fish represent a threat to Oregon spotted frogs that has significant
impacts (Pearl 1999, pp. 17-18). A study of the impacts of introduced
trout on Columbia spotted frog populations in Idaho revealed that,
although fish and adult frogs coexisted at many of the stocked lakes,
most stocked lakes contained significantly lower densities of all
amphibian life stages (Pilliod and Peterson 2001, p. 326). On the other
hand, results from the Willamette Valley in Oregon suggest that
nonnative, warm water fishes actually benefit introduced populations of
bullfrogs because of fish predation on macroinvertebrates that would
otherwise prey on bullfrog larvae (Adams et al. 2003, p. 347).
The presence of these nonnative species has been shown to increase
the time for metamorphosis and decrease the mass of native red-legged
frogs (Kiesecker and Blaustein 1997; Lawler et al. 1999, p. 617). A
recent study documented nonnative fish negatively influencing the
survival and growth of Pacific tree frogs while bullfrog larvae reduced
the growth but had no effect on survival (Preston et al. 2012, p.
1257). In addition, the predation effects of nonnative fish and
bullfrogs on Pacific tree frogs were additive, but those species had
little impact on each other (Preston et al. 2012, p. 1259). Many of the
sub-basins occupied by Oregon spotted frogs also have introduced warm-
and/or cold-water fish, and 5 of the 15 sub-basins are subject to high
to very high impacts due to predation of larvae and reduced winter
survival.
The ODFW stocks fish in most of the Cascades Lakes and two
reservoirs in the Upper Deschutes River sub-basin occupied by Oregon
spotted frogs (Hodgson 2012, pers. comm.). In addition to stocking,
there is natural production of various fish species, both native and
introduced, in the lakes and reservoirs in the Upper Deschutes River
sub-basin and in lakes in the McKenzie River and Middle Fork Willamette
sub-basins where spotted frogs occur (Hodgson 2012, pers. comm.; Ziller
2013, pers. comm.; USFS 2011a). The ODFW no longer stocks fish in any
of the moving waters associated with Oregon spotted frog locations
within the Klamath Basin (Tinniswood 2012, pers. comm.).
Bullfrogs introduced from eastern North America into the historical
range of the Oregon spotted frog may have contributed to losses of
populations. The introduction of bullfrogs may have played a role in
the disappearance of Oregon spotted frogs from the Willamette Valley in
Oregon and the Puget Sound area in Washington (Nussbaum et al. 1983, p.
187). Bullfrogs share similar habitat and temperature requirements with
the Oregon spotted frog, and the overlap in time and space between the
two species is believed to be extensive (Hayes 1994, p. 25; Hayes et
al. 1997, p. 5). Bullfrogs can reach high densities due to the
production of large numbers of eggs per breeding female and
unpalatability (and high survivorship) of tadpoles to predatory fish
(Kruse and Francis 1977, pp. 250-251). Bullfrog tadpoles outcompete or
displace tadpoles of native frog species from their habitat or optimal
conditions (Kupferberg 1997, pp. 1741-1746; Kiesecker and Blaustein
1998, pp. 783-
[[Page 51681]]
784; Kiesecker et al. 2001b, pp. 1966-1967).
Bullfrog adults achieve larger size than native western ranids and
even juvenile bullfrogs can consume native frogs (Hayes and Jennings
1986, p. 492; Pearl et al. 2004, p. 16). The digestive tracts of a
sample of 25 adult bullfrogs from Conboy Lake in Washington contained
nine Oregon spotted frogs, including seven adults (McAllister and
Leonard 1997, p. 13). A later examination of the stomachs of two large
bullfrogs revealed two adult or subadult Oregon spotted frogs in one
stomach and four in the second (Hayes 1999, pers. comm.). Bullfrogs
were recorded consuming hatchling Oregon spotted frogs at British
Columbia's Maintenance Detachment Aldergrove site (Haycock and Woods
2001, unpubl. data cited in COSFRT 2012, p. 19). In addition, the USGS
has observed Oregon spotted frogs within dissected bullfrogs at
multiple sites throughout the Deschutes and Klamath Basins (Pearl 2012,
pers comm.).
Oregon spotted frogs are more susceptible to predation by bullfrogs
than are northern red-legged frogs (Pearl et al. 2004, p. 16). Oregon
spotted frogs and northern red-legged frogs historically coexisted in
areas of the PNW that are now invaded by bullfrogs. However, the Oregon
spotted frog has declined more severely than the northern red-legged
frog. Pearl et al. (2004, p. 16) demonstrated in laboratory experiments
that the more aquatic Oregon spotted frog juveniles are consumed by
bullfrogs at a higher rate than are northern red-legged frog juveniles.
Oregon spotted frogs and northern red-legged frogs also differ in their
ability to escape bullfrogs, with Oregon spotted frogs having shorter
mean and maximum jump distances than northern red-legged frogs of equal
size. Bullfrogs, therefore, pose a greater threat to Oregon spotted
frogs than to red-legged frogs. Oregon spotted frog's microhabitat use
and escape abilities may be limiting their distributions in historical
lowland habitats where bullfrogs are present, whereas red-legged frog
populations are more stable (Pearl et al. 2004, pp. 17-18).
The ability of bullfrogs and Oregon spotted frogs to coexist may be
related to differences in seasonal and permanent wetland use. However,
a substantial bullfrog population has likely coexisted with Oregon
spotted frogs for nearly 50 years in Conboy Lake in Washington
(Rombough et al. 2006, p. 210). This long-term overlap has been
hypothesized to be the evolutionary driver for larger body size of
Oregon spotted frogs at Conboy Lake (Rombough et al. 2006, p. 210).
However, body size measurements have not been completed across the
range for a complete comparison to be made. Winterkill could be a
factor in controlling the bullfrog population at Conboy Lake and,
hence, facilitating co-existence with Oregon spotted frogs (Engler and
Hayes 1998, p. 2); however, the Oregon spotted frog population at
Conboy Lake has declined over the last decade, some of which is likely
due to bullfrog predation. Bullfrogs have been actively managed in the
Sunriver area in Oregon for more than 40 years, and despite efforts to
eradicate them, they have been expanding in distribution (Bowerman
2012, pers. comm.). Bullfrogs have been documented up to 4,300 feet
(1,311 m) elevation in the Little Deschutes River sub-basin in habitat
occupied by Oregon spotted frog. Bullfrogs have been found in 10 of the
15 sub-basins occupied by Oregon spotted frogs, but are relatively rare
at most of the locations where they co-occur. However, based on our
threats analysis, the impacts due to predation and/or competition with
bullfrogs within the Lower Fraser River, Middle Klickitat sub-basins in
Washington, and the Upper Klamath Lake sub-basin in Oregon are
considered to be high to very high because of the more extensive
overlap between these two species in these areas.
Green frogs (Lithobates clamitans) are native to the eastern United
States but have been introduced to the western United States and
Canada. This introduced species occurs at a few lakes in Whatcom
County, Washington (McAllister 1995; WDFW WSDM database), but Oregon
spotted frogs are not known to occur in these lakes. Green frogs do co-
occur with Oregon spotted frogs at Maria and Mountain Sloughs in
British Columbia (COSEWIC 2011, p. 36). Adult green frogs may eat young
Oregon spotted frogs, but adult Oregon spotted frogs may reach a size
that is too large to be prey for the species. Whether green frogs are
significant competitors of Oregon spotted frogs is currently unknown.
High population densities of green frogs possibly attract and maintain
higher than normal population densities of native predators, which in
turn increases predation pressure on Oregon spotted frogs (COSFRT 2012,
p. 19).
Conservation Efforts To Reduce Disease or Predation
Despite considerable knowledge about the habitat and management
requirements for Oregon spotted frog, refuge management at the Conboy
Lake NWR remains complex as habitat needs and the abatement of other
stressors often conflict with the conventional intensive wetland
management that occurs on the refuge (USFWS, 2010b, p. 64). The
historical Conboy Lake basin in Washington likely retained water for 10
to 12 months in most years. Currently, it retains water only during wet
years and is drained annually by the Conboy Lake NWR to control
bullfrogs for the benefit of Oregon spotted frogs. However, the
draining of the lakebed forces all surviving bullfrogs, fish, and
Oregon spotted frogs into the canal system for the fall and winter,
increasing potential predation on Oregon spotted frogs.
In the Upper and Little Deschutes River sub-basins in Oregon, there
has been little effort to control invasive predators. Bullfrog
eradication has been attempted at two sites within the Upper and Little
Deschutes sub-basins: Sunriver and Crosswater, respectively. However,
it appears that bullfrogs may be increasing in the Sunriver area
(Bowerman 2012, pers. comm.).
Current predator or disease conservation efforts in the Klamath
Basin in Oregon are limited to bullfrog control or eradication. The
USGS has conducted a bullfrog eradication program on Crane Creek since
bullfrogs appeared in 2010. In addition, the BLM has been controlling
and reducing bullfrogs and analyzing the gut contents of bullfrogs at
all life stages on their Wood River property in Oregon for 6 years.
Bullfrog detections and collection have decreased in different areas of
the canal in recent years (Roninger 2012, pers. comm.). The number of
bullfrogs removed and seen at this site has decreased, and in the last
few years, the bulk of the bullfrog removal has been from the north
canal and Seven-mile canal areas (outside the Oregon spotted frog
site), which is considered to be the strongest source areas for
movement into the Oregon spotted frog site (Roninger 2012, pers. comm).
However, despite these efforts, bullfrogs continue to persist in these
Oregon spotted frog habitats.
Summary of disease and predation--Saprolegnia, Bd, and Ribeiroia
ondatrae have been found in Oregon spotted frogs and compounded with
other stressors, such as UV-B exposure, degradation of habitat quality,
or increased predation pressure, may contribute to population declines.
Bd and R. ondatrae, in particular, infect post-metamorphic frogs and
reductions in these life stages are more likely to lead to population
declines in pond-breeding amphibians; however, these are not currently
known to be causing population declines in Oregon spotted frogs.
Disease continues
[[Page 51682]]
to be a concern, but more information is needed to determine the
severity of impact that diseases may have on Oregon spotted frogs.
Therefore, based on the best available scientific evidence, there is no
indication that disease is a threat to the Oregon spotted frog.
Introduced fish species prey on tadpoles, negatively affect
overwintering habitat, and can significantly threaten Oregon spotted
frog populations, especially during droughts, as aquatic habitat areas
become smaller and escape cover is reduced. Cushman et al. 2007 (p. 22)
states that both Hayes (1997) and Pearl (1999) hypothesized that low
water conditions have the potential to increase overlap between Oregon
spotted frog and nonnative predators such as brook trout and bullfrogs.
Increased overlap in habitat use between Oregon spotted frog and
nonnative predators is likely to result in greater loss to predation.
Bullfrogs (and likely green frogs) prey on juvenile and adult Oregon
spotted frogs and bullfrog larvae can outcompete or displace Oregon
spotted frog larvae, effectively reducing all Oregon spotted frog life
stages and posing a significant threat to Oregon spotted frogs. At
least one nonnative predaceous species occurs within each of the sub-
basins currently occupied by Oregon spotted frogs, and most sub-basins
have multiple predators. Nine of the 15 occupied sub-basins are
currently experiencing moderate to very high impacts due to predation,
and threats from predators are more concentrated in summer/rearing and
overwintering habitat. While some predator control occurs in a few sub-
basins, this work is not sufficient to ameliorate the threat from
predators.
Therefore, based on our review of the best information available,
we conclude that predation is a threat to Oregon spotted frogs
throughout the entire range of the species and is expected to continue
into the future.
Factor D. The Inadequacy of Existing Regulatory Mechanisms
Under this factor, we examine whether existing regulatory
mechanisms are inadequate to address the threats to the species
discussed under the other factors. Section 4(b)(1)(A) of the Act
requires the Service to take into account ``those efforts, if any,
being made by any State or foreign nation, or any political subdivision
of a State or foreign nation, to protect such specie. . . .'' In
relation to Factor D under the Act, we interpret this language to
require the Service to consider relevant Federal, State, and tribal
laws, regulations, and other such mechanisms that may minimize any of
the threats we describe in threat analyses under the other four
factors, or otherwise enhance conservation of the species. We give
strongest weight to statutes and their implementing regulations and to
management direction that stems from those laws and regulations. An
example would be State governmental actions enforced under a State
statute or constitution, or Federal action under statute.
Having evaluated the significance of the threat as mitigated by any
such conservation efforts, we analyze under Factor D the extent to
which existing regulatory mechanisms are inadequate to address the
specific threats to the species. Regulatory mechanisms, if they exist,
may reduce or eliminate the impacts from one or more identified
threats. In this section, we review existing State and Federal
regulatory mechanisms to determine whether they effectively reduce or
remove threats to the Oregon spotted frog.
Canadian Laws and Regulations
In Canada, few regulatory mechanisms protect or conserve Oregon
spotted frogs. In British Columbia, Oregon spotted frogs are on the
Conservation Data Centre's Red List. The Red List includes ecological
communities, indigenous species and subspecies that are extirpated,
endangered, or threatened in British Columbia; placing taxa on the Red
List flags them as being at risk and requiring investigation, but does
not confer any protection (British Columbia Ministry of Environment
2012, p. 1).
The Oregon spotted frog was determined to be endangered by the
Committee on the Status of Endangered Wildlife in Canada in 1999, with
status reexamined and confirmed in 2000 and 2011, and it received an
endangered determination under the Canadian Species at Risk Act (SARA)
in 2003 (COSFRT 2012, p. 1). SARA makes it an offense to kill, harm,
harass, capture or take an individual of a listed species that is
extirpated, endangered or threatened; or to possess, collect, buy, sell
or trade an individual of a listed species that is extirpated,
endangered or threatened, or any part or derivative of such an
individual (S.C. ch. 29 section 32); or damage or destroy the residence
of one or more individuals of a listed endangered or threatened species
or of a listed extirpated species if a recovery strategy has
recommended its reintroduction (S.C. ch, 29 sections 33, 58). For
species other than birds, the prohibitions on harm to individuals and
destruction of residences are limited to Federal lands. Three of the
four breeding locations in Canada occur wholly or partially on private
lands, which are not subject to SARA prohibitions (COSEWIC 2011, p.
38).
Habitat protection in British Columbia is limited to the Federal
Fisheries Act, British Columbia Water Act, and the provincial Riparian
Areas Regulation (COSEWIC 2011, p. 38). The Federal Fisheries Act
limits activities that can cause harmful alteration, disruption, or
destruction of fish habitat, with the primary goal being no net loss of
fish habitat. The British Columbia Water Act is the principal law for
managing the diversion and use of provincial water resources. License
holders are entitled to divert and use water; store water; construct,
maintain, and operate anything capable of or used for the proper
diversion, storage, carriage, distribution, and use of the water or the
power produced from it; alter or improve a stream or channel for any
purpose; and construct fences, screens, and fish or game guards across
streams for the purpose of conserving fish and wildlife (British
Columbia Water Act Part 2, section 5). The Riparian Areas Regulation
was enacted under Section 12 of the Fish Protection Act and calls on
local governments to protect riparian fish habitat during residential,
commercial, and industrial development. The habitat protections under
these Canadian Acts are designed to benefit fish species. As discussed
under Factor A, riparian protection and restoration actions designed
specifically to benefit fish can be detrimental to Oregon spotted frogs
and their habitat.
U.S. Federal Laws and Regulations
No Federal laws specifically protect the Oregon spotted frog.
Section 404 of the Clean Water Act (33 U.S.C. 1251 et seq.) is the
primary Federal law that is relevant to the Oregon spotted frog's
aquatic habitat. Through a permit process under section 404, the U.S.
Army Corps of Engineers (Corps) regulates the discharge of dredged or
fill material into waters of the United States, including navigable
waters and wetlands that may contain Oregon spotted frogs. However,
many actions highly detrimental to Oregon spotted frogs and their
habitats, such as irrigation diversion structure construction and
maintenance and other activities associated with ongoing farming
operations in existing cropped wetlands, are exempt from Clean Water
Act requirements.
In Washington and Oregon, current section 404 regulations provide
for the issuance of nationwide permits for at least 15 of the 52
categories of activities identified under the nationwide permit program
(USACOE 2012a, pp. 1-46),
[[Page 51683]]
which, for example, could result in the permanent loss of up to 500 ft
(150 m) of streambank and 1 ac (0.4 ha) of wetlands (USACOE 2012a,
2012b, 2012c). Projects authorized under a nationwide permit receive
minimal public and agency review, and in many cases, agency
notification is not required. Individual permits are subject to a more
rigorous review, and may be required for nationwide permit activities
with more than minimal impacts. Under both the individual and
nationwide permit programs, no activities can be authorized if they are
likely to directly or indirectly (1) jeopardize the continued existence
of a threatened or endangered species, or a species proposed for
designation, or (2) destroy or adversely modify the critical habitat of
such species, unless section 7 consultation addressing the effects of
the proposed activity has been completed. During section 7
consultation, effects to the species itself and aquatic habitat/
wetlands would be considered.
For nationwide permits, Corps notification may not be required
depending upon the project type and the amount of wetland to be
impacted. Impacts to wetlands may be authorized with no compensatory
mitigation in some cases. In other cases, wetland impacts may be
authorized if the permittee demonstrates the project footprint has been
designed to avoid most wetland impacts and unavoidable impacts can be
adequately mitigated through wetland creation, restoration, or
enhancement. For example, nationwide permits authorize the discharge of
fill material into 0.25 ac (0.1 ha) of wetlands with no requirement for
compensatory mitigation. In situations where compensatory wetland
mitigation is required, in kind mitigation is preferred but not
required.
A Washington State wetland mitigation evaluation study (Johnson et
al. 2002b, entire) found a resulting net loss of wetlands with or
without compensatory mitigation, because wetland creation and
enhancement projects were minimally successful or not successful in
implementation, nor did they achieve their ecologically relevant
measures. In general, most riparian habitat restoration in Washington
is targeted toward salmon species and does not include floodplain
depression wetlands. In Washington, mitigation sites within the South
Fork Nooksack, Samish, and Black River sub-basins have been designed to
improve water quality by planting trees and shrubs. Some of these
activities have been conducted in Oregon spotted frog breeding habitat.
Therefore, an activity that fills Oregon spotted frog habitat could be
mitigated by restoring and or creating riparian habitat suitable for
fish, but which is not suitable for frogs.
State Laws and Regulations
Washington--Although there is no State Endangered Species Act in
Washington, the Washington Fish and Wildlife Commission has the
authority to list species (RCW 77.12.020). State-listed species are
protected from direct take, but their habitat is not protected (RCW
77.15.120). The Oregon spotted frog was listed as a State endangered
species in Washington in August 1997 (Watson et al. 1998, p. 1; 2003,
p. 292; WAC 232-12-014). State listings generally consider only the
status of the species within the State's borders, and do not depend
upon the same considerations as a potential Federal listing. Unoccupied
or unsurveyed habitat is not protected unless by County ordinances or
other similar rules or laws.
Oregon spotted frogs are a Priority Species under WDFW's Priority
Habitats and Species Program (WDFW 2008, pp. 68). As a Priority
Species, the Oregon spotted frog may receive some protection of its
habitat under environmental reviews of applications for county or
municipal development permits and through implementation of priority
habitats and species management recommendations. Priority habitat and
species management recommendations for this species include maintaining
stable water levels and natural flow rates; maintaining vegetation
along stream banks or pond edges; avoidance of introducing nonnative
amphibians, reptiles, or fish; avoidance of removing algae from rearing
areas; avoiding alteration of muddy substrates; controlling stormwater
runoff away from frog habitat; avoiding application of pesticides in or
adjacent to waterbodies used by Oregon spotted frogs; and surveying
within the historical range of the species (Nordstrom and Milner 1997,
pp. 6-5--6-6).
The Clean Water Act requires States to set water quality standards
to protect beneficial uses, identify sources of pollution in waters
that fail to meet State water quality standards (Section 303(d)), and
to develop water quality plans to address those pollutants. Although
the Clean Water Act is a Federal law, authority for implementing this
law has been delegated to the State. Washington State adopted revised
water quality standards for temperature and intergravel dissolved
oxygen in December 2006, and the Environmental Protection Agency (EPA)
approved these revised standards in February 2008 (EPA 2008). Although
candidate species were not the focus, proponents believed that the
proposed standards would likely protect native aquatic species. The
temperature standards are intended to restore thermal regimes to
protect sensitive native salmonids, and, if temperature is not a
limiting factor in sustaining viable salmonid populations, other native
species would likely be protected (EPA 2007, p. 14).
The State has developed water quality plans for the Lower Nooksack,
Samish, and Upper Chehalis Rivers; however, as of 2008 (most recent
freshwater listing), portions of the Sumas River; Black Slough in the
South Fork Nooksack River sub-basin; portions of the Samish River;
segments of the Black River; segments of Dempsey, Allen, and Beaver
Creeks in the Black River drainage; and a segment in the upper portion
of Trout Lake Creek were listed by the Washington Department of Ecology
(WDOE) as not meeting water quality standards for a variety of
parameters, including temperature, fecal coliform, pH, and dissolved
oxygen (see Factor E discussion). In addition, for the streams/rivers
where the temperature or fecal coliform standard is exceeded, the water
quality plans call for planting trees and shrubs and excluding cattle,
which would not be conducive to the creation and maintenance of
emergent vegetation stage conditions necessary for Oregon spotted frog
egg-laying habitat (see Factor A discussion).
Oregon--Oregon has a State Endangered Species Act, but the Oregon
spotted frog is not State listed. Although this species is on the
Oregon sensitive species list and is considered critically sensitive,
this designation provides little protection (ODFW 1996, OAR 635-100-
0040). A Federal listing does not guarantee a listing under the Oregon
State Endangered Species Act; rather a State listing requires a
separate rulemaking process and findings made by the Oregon Fish and
Wildlife Commission (OAR 635-100-0105 and 635-100-0110).
Although the Clean Water Act is a Federal law, authority for
implementing this law has been delegated to the State. Oregon adopted
revised water quality standards for temperature, intergravel dissolved
oxygen, and anti-degradation in December 2003, and EPA approved these
revised standards in March 2004 (EPA 2004). Although candidate species
were not the focus, it was believed that the proposed standards would
likely protect native aquatic species. The proposed temperature
standards are intended to restore thermal regimes to protect sensitive
native salmonids and,
[[Page 51684]]
if temperature is not a limiting factor in sustaining viable salmonid
populations, other native species would likely be protected (EPA 2004).
In December 2012, EPA approved additions to Oregon's 303(d) list, which
includes waterbodies that do not meet water quality standards for
multiple parameters (ODEQ 2012). Many of the streams associated with
Oregon spotted frog habitat are 303(d) listed by the Oregon Department
of Environmental Quality (see Factor E).
Oregon's Removal-Fill Law (ORS 196.795-990) requires people who
plan to remove or fill material in waters of the State to obtain a
permit from the Department of State Lands. Wetlands and waterways in
Oregon are protected by both State and Federal laws. Projects impacting
waters often require both a State removal-fill permit, issued by the
Department of State Lands (DSL), and a Federal permit issued by the
Corps. A permit is required only if 50 cubic yards (cy) or more of fill
or removal will occur. The removal fill law does not regulate the
draining of wetlands (see ``Local Laws and Regulations,'' below).
Local Laws and Regulations
Washington--The Washington Shoreline Management Act's purpose is
``to prevent the inherent harm in an uncoordinated and piecemeal
development of the State's shorelines.'' Shorelines are defined as: All
marine waters; streams and rivers with greater than 20 cfs (0.6 cms)
mean annual flow; lakes 20 ac or larger; upland areas called shorelands
that extend 200 ft (61 m) landward from the edge of these waters; and
the following areas when they are associated with one of the previous
shorelines: Biological wetlands and river deltas, and some or all of
the 100-year floodplain, including all wetlands within the 100-year
floodplain. Each city and county with ``shorelines of the state'' must
prepare and adopt a Shoreline Master Program (SMP) that is based on
State laws and rules but is tailored to the specific geographic,
economic, and environmental needs of the community. The local SMP is
essentially a shoreline-specific combined comprehensive plan, zoning
ordinance, and development permit system.
The Washington State Growth Management Act of 1990 requires all
jurisdictions in the State to designate and protect critical areas. The
State defines five broad categories of critical areas, including (a)
wetlands; (b) areas with a critical recharging effect on aquifers used
for potable water; (c) fish and wildlife habitat conservation areas;
(d) frequently flooded areas; and (e) geologically hazardous areas. The
County Area Ordinance (CAO) is the county regulation that most directly
addresses protection of the critical areas mapped by each county.
Frequently, local government will have adopted zoning regulations
and comprehensive land use plans that apply both within and outside
shoreline areas. When these codes are applied within the shoreline
area, there may be differences in the zoning regulations and the plan
policies as compared with the regulations and policies of the SMP.
Because the SMP is technically a State law (i.e., WAC), the
requirements of the SMP will prevail in the event of a conflict with
the local zoning or plan. Generally, however, a conflict will not exist
if the zoning or plan requirements are more protective of the shoreline
environment than the SMP. For example, if the zoning district allows a
density of one unit per acre, and the SMP allows a density of two units
per, the requirements of the more restrictive code would prevail.
Within each county in Washington, the SMP and CAO are the
regulations that most directly address protection of Oregon spotted
frog habitat. A brief discussion of the current SMPs and CAOs for the
five counties where Oregon spotted frogs are known to occur follows.
Whatcom County: Whatcom County updated its Shoreline Management
Program (known as a Shoreline Master Program in the Growth Management
Act) in 2008 (Whatcom County Shoreline Management Program 2008). Based
on interpretation of the 2008 Shoreline Management Program, the known
Oregon spotted frog occupied locations in the Lower Chilliwack or South
Fork Nooksack River sub-basins are not ``shorelines.'' Samish River
within Whatcom County is designated as Conservancy Shoreline that
provides specific allowed uses and setbacks. Presently, the two primary
uses of this area are agricultural and residential, both of which are
allowed under the Shoreline Management Program, with some restrictions.
Restrictions include shoreline setbacks of 15-20 ft (4.5-6.1 m) and
allowance of no more than 10 percent impervious surface (although it is
uncertain whether this is applicable on a per-project, per-acre, or
per-basin basis). One of the allowed uses is restoration, which is
focused on recovery of salmon and bull trout. Many of the restoration
actions targeting salmon and bull trout recovery are not conducive to
maintaining emergent wetland vegetation stages necessary to maintain
Oregon spotted frog egg-laying habitat. Some activities would require a
permit that must be reviewed and approved by Whatcom County and the
WDOE for consistency.
The Whatcom County CAO that is the most relevant to Oregon spotted
frogs applies to wetland areas, which are present in the three sub-
basins where Oregon spotted frogs occur in this county. Activities in
all wetlands are regulated unless the wetland is 1/10 ac or smaller in
size; however, activities that can destroy or modify Oregon spotted
frog habitat can still occur under the existing CAO. Activities that
are conditionally allowed include surface water discharge; storm water
management facilities; storm water conveyance or discharge facilities;
public roads, bridges, and trails; single-family developments; and
onsite sewage disposal systems. Buffers and mitigation are required,
but can be adjusted by the county. In general, wetlands and the
associated wetland buffer CAOs target an avoidance strategy, which may
not be beneficial to the maintenance of Oregon spotted frog emergent
wetland habitat on a long-term basis in areas where reed canarygrass is
present. Within the areas occupied by Oregon spotted frogs in the three
sub-basins, all breeding habitat is within seasonally flooded areas,
which may or may not be defined as wetlands. Rather than an avoidance
strategy, these areas may require management actions to remove reed
canarygrass in order to maintain breeding habitat and provide for
Oregon spotted frog persistence. Within Whatcom County, protective
measures for Oregon spotted frogs are afforded under both the SMP and
the CAOs, although no measures are specifically directed toward this
species.
Skagit County: Skagit County's revisions to its SMP are under
review (http://www.skagitcounty.net). Until the revised SMP is approved
by WDOE, the 1976 SMP remains in effect (Skagit County SMP 1976). The
portion of the Samish River in Skagit County is designated as Rural
Shoreline Area, and typified by low overall structural density, and low
to moderate intensity of agriculture, residential development, outdoor
recreation, and forestry operations uses. This designation is intended
to maintain open spaces and opportunities for recreational activities
and a variety of uses compatible with agriculture and the shoreline
environment. Presently, the two primary uses of the Samish River where
Oregon spotted frogs occur are agricultural and residential. With some
restrictions, almost all activities are allowed within this
designation, and the draining of wetlands is not prohibited.
Agricultural users are encouraged to retain
[[Page 51685]]
vegetation along stream banks. Developments and sand and gravel
extractions are allowed provided they are compatible with agricultural
uses. These types of activities can be detrimental to Oregon spotted
frog breeding habitat.
The Skagit County CAO designates lands adjacent to the Samish River
where Oregon spotted frogs are known to occur as Rural Resource or
Agricultural. These land designations and the associated allowed
activities are intended to provide some protection of hydrological
functions, but they are primarily designed to retain a rural setting
(low residential density) or to ensure the stability and productivity
of agriculture and forestry in the county, which has some benefits to
the Oregon spotted frog.
Thurston County: Thurston County's revision of its SMP is currently
under way, and until the revised SMP is completed and approved, the
1990 SMP remains in effect (Thurston County SMP 1990). The majority of
the areas within the Black River that are known to be occupied by
Oregon spotted frogs are either undesignated (primarily the
tributaries) or designated as Natural or Conservancy Environments. Two
small areas are designated as Urban at the town of Littlerock and along
Beaver Creek. Fish Pond Creek, a known Oregon spotted frog breeding
location, is within the designated Tumwater Urban Growth Area. Within
the Natural Environment designation areas, most activity types are
prohibited, although livestock grazing, low-intensity recreation, low-
density (1 domicile per 10 ac) residences, and conditional shoreline
alterations are allowed. Within Conservancy Environments, most
activities are conditionally allowed, and would require a permit that
must be reviewed and approved by Thurston County and WDOE for
consistency with the SMP.
Thurston County approved a revision to the CAO in July 2012. The
Thurston County CAO that is the most relevant to Oregon spotted frogs
addresses wetlands, although the Fish and Wildlife Habitat Conservation
Areas chapter and the 100-year floodplain and Channel Migration Zone
designations are also applicable. Activities in most wetlands are
regulated, other than those less than or equal to 1,000 square feet
(ft\2\) in size (although the county can waive this size threshold if a
priority species is known to occur). However, due to State law, the
2012 CAO update did not address agricultural activities, and the
jurisdictional wetland size for these activities is 22,000 ft\2\ in the
rural county, 11,000 ft\2\ in Urban Growth Areas, or 2,500 ft\2\ if
adjacent to a stream or its floodplain. As a result, activities that
can destroy or modify Oregon spotted frog habitat may still occur, such
as asphalt batch plant construction, new agricultural uses, boat ramps,
docks, piers, floats, bridge or culvert projects, clearing-grading-
excavation activities, and dredging/removal operations. Buffers and
mitigation are required, but can be adjusted by the county. In general,
wetlands and the associated wetland buffer CAOs strive toward a no-
management approach, which may not be beneficial to the maintenance of
Oregon spotted frog emergent wetland habitat on a long-term basis.
Within the areas occupied by Oregon spotted frogs in the Black River,
all breeding habitat is within seasonally flooded areas, which may or
may not be defined as wetlands or high ground water hazard areas (both
designations would require set-backs). Rather than an avoidance
strategy, these areas may require management actions to remove reed
canarygrass in order to maintain egg-laying habitat. Seasonally flooded
areas where agricultural uses are existing and ongoing are exempt from
review under the CAO; however, expansion of activities may trigger
additional review. Within Thurston County, protective measures for
Oregon spotted frogs are afforded under both the SMP and CAOs, although
no measures are specifically directed toward this species.
Skamania County: Skamania County's revision to its SMP is under
way, and until revised, the 1980 SMP is in effect (Skamania County SMP
1980). According to the 1980 SMP, Trout Lake Creek is not a shoreline
of Skamania County. The portions of Trout Lake Creek that are in
Skamania County have no designated critical areas. Therefore, the SMP
and CAO are not applicable to Oregon spotted frog habitat in Skamania
County.
Klickitat County: Klickitat County's SMP was adopted in 1998, and
revised in 2007 (Klickitat County SMP 2007). Based on the 2007 SMP,
only Trout Lake Creek is considered a ``shoreline,'' and within the
area occupied by Oregon spotted frogs, regulations for both Natural and
Conservancy Environments apply. Within the Natural Environments, most
activity types are prohibited, except for nonintensive pasturing or
grazing, recreation (access trails/passive uses), bulkheads
(conditional uses), and shoreline alterations (conditional). Within
Conservancy Environments, most activities are conditionally allowed,
and require a permit that must be reviewed and approved by Klickitat
County and WDOE for consistency.
Klickitat County's CAO was adopted in 2001, and amended in 2004.
Mapping of critical areas was not available, so our analysis includes
only wetlands provisions. Activities in all wetlands greater than 2,500
ft\2\ (232 m\2\) in size are regulated; however, some activities are
exempted, including agricultural uses and maintenance of surface water
systems (for example, irrigation and drainage ditches). These types of
activities can destroy or modify Oregon spotted frog habitat. Buffers
and mitigation are required, but can be adjusted by the county. In
general, wetlands and the associated wetland buffer CAOs strive toward
a no-management approach, which may result in the loss of Oregon
spotted frog emergent wetland habitat on a long-term basis. Within the
areas occupied by Oregon spotted frogs in Klickitat County, all
breeding habitat is within seasonally flooded areas, which may or may
not be defined as wetlands. Rather than an avoidance strategy, these
areas may require management actions to remove reed canarygrass in
order to maintain egg-laying habitat. Within Klickitat County,
protective measures for Oregon spotted frogs are afforded under both
the SMP and CAOs, although no measures are specifically directed toward
this species.
Oregon--In Oregon, the Land Conservation and Development Commission
in 1974 adopted Goal 5 as a broad, Statewide planning goal that covers
more than a dozen resources, including wildlife habitats and natural
areas. Goal 5 and related Oregon Administrative Rules (Chapter 660,
Divisions 16 and 23) describe how cities and counties are to plan and
zone land to conserve resources listed in the goal. Goal 5 is a
required planning process that allows local governments to make
decisions about land use regulations and whether to protect the
individual resources based upon potential conflicts involving economic,
social, environmental, and energy consequences. It does not require
minimum levels of protections for natural resources, but does require
weighing the various impacts to resources from land use.
Counties in Oregon within the range of Oregon spotted frog may have
zoning ordinances that reflect protections set forth during the Goal 5
planning process. The following will briefly discuss these within each
county where Oregon spotted frogs are currently known to occur.
Deschutes County: In accordance with the Statewide planning process
[[Page 51686]]
discussed above, Deschutes County completed a comprehensive plan in
1979, which was updated in 2011, although Oregon spotted frog habitat
is not included within the comprehensive plan as a Goal 5 resource
site. The comprehensive plan is implemented primarily through zoning.
Deschutes County zoning ordinances that regulate the removal and fill
of wetlands (18.128.270), development within the floodplain
(18.96.100), and siting of structures within 100 ft (30 m) of streams
may provide indirect protections to Oregon spotted frog habitat on
private lands along the Upper and Little Deschutes Rivers. The
Deschutes County zoning regulations do not regulate the draining of
wetlands or hydrologic modifications, and the Oregon Division of State
Lands (DSL) regulates only actions that involve more than 50 cy (38
m\3\) of wetland removal. Therefore, development associated with small
wetland removals is neither regulated under the Deschutes County
comprehensive plan nor Oregon DSL, which could negatively impact Oregon
spotted frog habitat.
Klamath County: Article 57 of the Klamath County Comprehensive Plan
Policy (KCCPP) and associated Klamath County Development Code (KCDC)
mandates provisions to preserve significant natural and cultural
resources; address the economic, social, environmental, and energy
consequences of conflicting uses upon significant natural and cultural
resources; and permit development in a manner that does not adversely
impact identified resource values (KCDC 2005, p. 197). This plan
identifies significant wetlands, riparian areas, Class I streams, and
fish habitat as a significant resource and identifies potentially
conflicting uses including shoreline development or alteration, removal
of riparian vegetation, filling or removing material, in-stream
modification, introduction of pollutants, water impoundments, and
drainage or channelization (KCCPP 2005, pp. 33-34, KCDC 2005, p. 199).
All land uses that represent these conflicting uses are reviewed and
applicants must clearly demonstrate that the proposed use will not
negatively impact the resource (KCDC 2005, p. 200; KCCPP 2005, p. 25).
However, all accepted farm practices or forest practices are exempt
from this provision (KCDC 2005, p. 198), including (but not limited to)
buildings, wineries, mineral exploration, and, under certain
circumstances, the establishment of golf courses and agricultural and
commercial industries (KCDC 2005, pp. 160-163, 176-177). If any of
these practices disturb less than 50 cy (38.2 m\3\) of wetlands, they
are not regulated by either KCCPP or Oregon DSL. Therefore, the
development associated with small wetland removals could negatively
impact Oregon spotted frog habitat.
Jackson County: No specific county regulations pertain to wetlands
within Jackson County ordinances. This county relies on the Oregon DSL
to regulate the development and protection of wetlands (Skyles 2012,
pers. comm.).
Summary of Existing Regulatory Mechanisms
The existing regulatory mechanisms described above are not
sufficient to reduce or remove threats to the Oregon spotted frog
habitat, particularly habitat loss and degradation. The lack of
essential habitat protection under Federal, State, Provincial, and
local laws leaves this species at continued risk of habitat loss and
degradation in British Columbia, Washington, and Oregon. The review of
impacts to wetlands under the Clean Water Act is minimal, and several
occupied sub-basins in Washington and Oregon do not meet water quality
standards. In many cases, laws and regulations that pertain to
retention and restoration of wetland and riverine areas are designed to
be beneficial to fish species, specifically salmonids, resulting in the
unintentional elimination or degradation of Oregon spotted frog
habitat. For example, CAOs in some Washington counties prohibit grazing
within the riparian corridor, which is an active management technique
that, properly applied, can be used to control invasive reed
canarygrass.
Additional regulatory flexibility would be desirable for actively
maintaining habitat in those areas essential for the conservation of
Oregon spotted frog. We note that the area where these potential
incompatibilities apply are limited in scope (i.e., approximately 5,000
ac (2,000 ha) and 20 mi (33 km) along the Black Slough and Sumas,
Samish, and Black Rivers in Washington), because the area inhabited by
Oregon spotted frogs is quite small relative to the extensive range of
salmonids. In other cases, no regulations address threats related to
the draining or development of wetlands or hydrologic modifications,
which can eliminate or degrade Oregon spotted frog habitat. In summary,
degradation of habitat for the Oregon spotted frog is ongoing despite
existing regulatory mechanisms. These regulatory mechanisms have been
insufficient to significantly reduce or remove the threats to the
Oregon spotted frog. Therefore, based upon our review of the best
information available, we conclude that the existing regulatory
mechanisms are inadequate to reduce the threats to the Oregon spotted
frog.
Factor E. Other Natural or Manmade Factors Affecting Its Continued
Existence
Site Size and Isolation/Population Turnover Rates/Breeding Effort
Concentrations and Site Fidelity
Most species' populations fluctuate naturally in response to
weather events, disease, predation, or other factors. These factors,
however, have less impact on a species with a wide and continuous
distribution. In addition, smaller, isolated populations are generally
more likely to be extirpated by stochastic events and genetic drift
(Lande 1988, pp. 1456-1458). Many of the Oregon spotted frog breeding
locations comprise fewer than 50 adult frogs, are isolated from other
breeding locations, and may already be stressed by other factors, such
as drought or predation, and are then more vulnerable to random,
naturally occurring events. Where Oregon spotted frog locations have
small population sizes and are isolated, their vulnerability to
extirpation from factors such as fluctuating water levels, disease, and
predation increases.
Funk et al. (2008, p. 205) found low genetic variation in Oregon
spotted frogs, which likely reflects small effective population sizes,
historical or current genetic bottlenecks, and/or low gene flow among
populations. Genetic work by Blouin et al. (2010) indicates low genetic
diversity within and high genetic differentiation among each of the six
Oregon spotted frog groups (British Columbia, Chehalis and Columbia
drainages, Camas Prairie, central Oregon Cascades, and the Klamath
Basin). This pattern of genetic fragmentation is likely caused by low
connectivity between sites and naturally small populations sizes. Gene
flow is very limited between locations, especially if separated by 6 mi
(10 km) or more, and at the larger scale, genetic groups have the
signature of complete isolation (Blouin et al. 2010, p. 2187). At least
two of the locations sampled by Blouin et al. (2010) (Camas Prairie and
Trout Lake) show indications of recent genetic drift.
Modeling across a variety of amphibian taxa suggests that pond-
breeding frogs have high temporal variances of population abundances
and high local extinction rates relative to other groups of amphibians,
with smaller frog populations undergoing disproportionately large
fluctuations in
[[Page 51687]]
abundance (Green 2003, pp. 339-341). The vulnerability of Oregon
spotted frog egg masses to fluctuating water levels (Hayes et al. 2000,
pp. 10-12; Pearl and Bury 2000, p. 10), the vulnerability of post-
metamorphic stages to predation (Hayes 1994, p. 25), and low
overwintering survival (Hallock and Pearson 2001, p. 8) can contribute
to relatively rapid population turnovers, suggesting Oregon spotted
frogs are particularly vulnerable to local extirpations from stochastic
events and chronic sources of mortality (Pearl and Hayes 2004, p. 11).
The term ``rapid population turnovers'' refers to disproportionately
large fluctuations in abundance.
Oregon spotted frogs concentrate their breeding efforts in
relatively few locations (Hayes et al. 2000, pp. 5-6; McAllister and
White 2001, p. 11). For example, Hayes et al. (2000, pp. 5-6) found
that 2 percent of breeding sites accounted for 19 percent of the egg
masses at the Conboy Lake NWR. Similar breeding concentrations have
been found elsewhere in Washington and in Oregon. Moreover, Oregon
spotted frogs exhibit relatively high fidelity to breeding locations,
using the same seasonal pools every year and often using the same egg-
laying sites. In years of extremely high or low water, the frogs may
use alternative sites. For example, the Trout Lake Creek and Conboy
Lake frogs return to traditional breeding areas every year, but the
egg-laying sites change based on water depth at the time of breeding. A
stochastic event that impacts any one of these breeding locations could
significantly reduce the Oregon spotted frog population associated with
that sub-basin.
Egg mass count data suggest a positive correlation and significant
link between site size and Oregon spotted frog breeding population size
(Pearl and Hayes 2004, p. 12). Larger sites are more likely to provide
the seasonal microhabitats required by Oregon spotted frogs, have a
more reliable prey base, and include overwintering habitat. The minimum
amount of habitat thought to be required to maintain an Oregon spotted
frog population is about 10 ac (4 ha) (Hayes 1994, Part II pp. 5 and
7). Smaller sites generally have a small number of frogs and, as
described above, are more vulnerable to extirpation. Some sites in
Oregon are at or below the 10-ac (4-ha) threshold; however, Pearl and
Hayes (2004, p. 14) believe that these sites were historically
subpopulations within a larger breeding complex and Oregon spotted
frogs may only be persisting in these small sites because the sites
exchange migrants or seasonal habitat needs are provided nearby.
Movement studies suggest Oregon spotted frogs are limited in their
overland dispersal and potential to recolonize sites. Oregon spotted
frog movements are associated with aquatic connections (Watson et al.
2003, p. 295; Pearl and Hayes 2004, p. 15). However, within 10 of the
15 occupied sub-basins, one or more of the known breeding locations are
isolated and separated by at least 3.1 mi (5 km) (see Life History,
above), and within 9 of the 15 sub-basins, one or more of the known
breeding locations are isolated and separated by at least 6 mi (10 km),
the distance over which gene flow is extremely low (see Taxonomy,
above). In many instances the intervening habitat lacks the substantial
hydrological connections that would allow Oregon spotted frog movement.
In addition, widespread predaceous fish introductions within these
corridors pose a very high risk to frogs that do try to move between
known locations. Therefore, should a stochastic event occur that
results in the extirpation of an area, natural recolonization is
unlikely unless another known location is hydrologically connected and
within 3.1 mi (5 km).
In British Columbia, the distance between the Morris Valley,
Mountain Slough, and Maria Slough locations is about 8 km and each of
these locations is 50-60 km from Maintenance Detachment Aldergrove,
making all of the known populations isolated from one another (COSFRT
2012, p. 15). In addition, suitable wetland habitat between any two of
these locations is highly fragmented, and movement between populations
is unlikely to occur. Based on this information and the small number of
breeding individuals (fewer than 350), the Canadian Oregon spotted frog
recovery team found that the risk from demographic and environmental
stochastic events is high and could result in further local
extirpations (COSFRT 2012, p. v).
In five of the six extant sub-basins in Washington, Oregon spotted
frogs are restricted to one watershed within the sub-basin. Within four
of these sub-basins (South Fork Nooksack, Samish, White Salmon, and
Middle Klickitat Rivers), the known breeding locations are aquatically
connected, such that movements could occur and facilitate genetic
exchange. In the Lower Chilliwack, Oregon spotted frogs are currently
known to occur from only one breeding location in one watershed (Sumas
River). There may be additional locations within 3.1 mi (5 km) that are
aquatically connected, but further surveys would be needed in order to
make this determination. In the Black River, known breeding locations
occur along the mainstem, as well as in six tributaries. Oregon spotted
frogs in Fish Pond Creek are likely isolated from Oregon spotted frogs
in the rest of the Black River system due to changes in the outflow of
Black Lake. Black Lake Ditch was constructed in 1922, and a pipeline at
the outlet of the Black Lake to Black River was constructed in the
1960s; both of these structures changed the flow such that Black Lake
drains to the north, except during high flows rather than down the
Black River as it did historically (Foster Wheeler Environmental
Corporation 2003, pp. 2, 3, 5, 24). Oregon spotted frogs in the other
five tributaries may also be isolated from each other because there is
little evidence that the frogs use the Black River to move between
tributaries, although breeding locations in these tributaries are
aquatically connected via the Black River.
In Oregon, two of the eight extant sub-basins contain single,
isolated populations of Oregon spotted frogs: Lower Deschutes River
(i.e., Camas Prairie) and Middle Fork Willamette River (i.e., Gold
Lake). The McKenzie River sub-basin contains two populations of Oregon
spotted frogs that are in close proximity but have no apparent
hydrologic connection to each other or to populations in other sub-
basins. In the Deschutes River Basin, Oregon spotted frog breeding
sites are found throughout two sub-basins: The Upper Deschutes River
and the Little Deschutes River. These two sub-basins are aquatically
connected at the confluence of the Little Deschutes River and the
mainstem Deschutes River below Wickiup Reservoir. Genetic exchange
likely occurs between Oregon spotted frogs on the lower reach of the
Little Deschutes River and those along the Deschutes River at Sunriver
where breeding occurs within 3.1 mi (5 km). The Wickiup dam and
regulated flows out of the reservoir limit connectivity for Oregon
spotted frogs to move within the Upper Deschutes River sub-basin, such
that connectivity between the populations above and below the dam are
unlikely. There are at least five breeding locations below Wickiup
Reservoir, two of which are within 6 mi (10 km) but separated by a
waterfall along the Deschutes River. Above Wickiup Reservoir, there are
approximately six clusters of breeding sites that may be isolated from
each other by lack of hydrologic connectivity
[[Page 51688]]
(i.e., lakes without outlets) or distances greater than 6 mi (10 km).
In the Little Deschutes River sub-basin, approximately 23 known
breeding locations are within five watersheds: Upper, Middle and Lower
Little Deschutes River; Crescent Creek; and Long Prairie. Most breeding
locations throughout the Little Deschutes River sub-basin are within 6
mi (10 km) of each other, and, given that much of the private land is
unsurveyed, the distance between breeding areas is likely smaller. In
the lower reach of the Little Deschutes River near the confluence with
the Deschutes River where more extensive surveys have been conducted,
breeding sites are within 3.1 mi (5 km). Wetland complexes are
extensive and continuous along the Little Deschutes River and its
tributaries, which likely provides connectivity between breeding areas.
Regulated flows out of Crescent Lake may affect the aquatic
connectivity between breeding locations, although the impacts to Oregon
spotted frog connectivity are not fully understood. The Long Prairie
watershed also has been hydrologically altered by the historical
draining of wetlands and ditching to supply irrigation water.
Connectivity between three known breeding locations within this
watershed is likely affected by the timing and duration of regulated
flows, and historic ditching for irrigation.
Oregon spotted frogs are found in six watersheds within three sub-
basins of the Klamath River Basin in Oregon (Williamson River, Upper
Klamath Lake, and Upper Klamath). Within the Williamson River sub-
basin, individuals in the Jack Creek watershed are isolated from other
populations due to lack of hydrologic connectivity. The Klamath Marsh
and Upper Williamson populations are aquatically connected such that
movements could occur and facilitate genetic exchange, although this
presumed gene flow has not been demonstrated by recent genetic work
(Robertson and Funk 2012, p. 10).
The Upper Klamath Lake sub-basin populations are found in two
watersheds: Wood River and Klamath Lake. Populations within and
adjacent to the Wood River are aquatically connected and genetically
similar (Robertson and Funk 2012, p. 10). However, while the Wood River
populations and the Klamath Lake populations have genetic similarities
(Robertson and Funk 2012, pp. 10, 11), altered hydrologic connections,
distances (>6 mi (terrestrial) (10 km)), and invasive species have
created inhospitable habitat. These conditions make it unlikely that
individual frogs are able to move between watersheds or establish
additional breeding complexes along the current hydrologic system. The
only potential for hydrologic connectivity and movement between
populations in the Klamath Lake populations is between Sevenmile Creek
and Crane Creek, and between the individual breeding complexes on the
Wood River in the Wood River watershed. The Upper Klamath sub-basin's
Parsnip Lakes and Buck Lake populations are isolated from each other
and the other Klamath Basin populations (Robertson and Funk 2012, p. 5)
due to great hydrological distances (>20 mi (32 km)) and barriers
(inhospitable habitat and dams).
Site size and isolation/population turnover rates/breeding effort
concentrations and site fidelity conclusion--Historically, Oregon
spotted frogs were likely distributed throughout a watershed, occurred
in multiple watersheds within a sub-basin, and adjusted their breeding
areas as natural disturbances, such as flood events and beaver
activity, shifted the location and amount of appropriate habitat.
Currently, Oregon spotted frogs are restricted in their range within
most occupied sub-basins (in some cases only occurring in one
watershed), and breeding areas are isolated (greater than dispersal
distance apart). Many of the Oregon spotted frog breeding locations
across the range comprise fewer than 50 adult frogs and are isolated
from other breeding locations. Genetic work indicates low genetic
diversity within and high genetic differentiation among the six Oregon
spotted frog groups. Each of these groups have the signature of
complete isolation, and two show indications of recent genetic drift (a
change in the gene pool of a small population that takes place strictly
by chance). Oregon spotted frogs can experience rapid population
turnovers because of their breeding location fidelity and vulnerability
to fluctuating water levels, predation, and low overwinter survival. A
stochastic event at any one of these small, isolated breeding locations
could significantly reduce the Oregon spotted frog population
associated with that sub-basin. Therefore, based on the best
information available, we consider small site size and isolation and
small population sizes to be a threat to the Oregon spotted frog.
Water Quality and Contamination
Poor water quality and water contamination are playing a role in
the decline of Oregon spotted frogs, and water quality concerns have
been specifically noted within six of the occupied sub-basins (see
Table 2 under Cumulative Effects from Factors A through E, below, and
Factor D discussion, above), although data specific to this species are
limited. Because of this limitation, we have examined responses by
similar amphibians as a surrogate for impacts on Oregon spotted frogs.
Studies comparing responses of amphibians to other aquatic species have
demonstrated that amphibians are as sensitive as, and often more
sensitive than, other species when exposed to aquatic contaminants
(Boyer and Grue 1995, p. 353). Immature amphibians absorb contaminants
during respiration through the skin and gills. They may also ingest
contaminated prey. Pesticides, heavy metals, nitrates and nitrites, and
other contaminants introduced into the aquatic environment from urban
and agricultural areas are known to negatively affect various life
stages of a wide range of amphibian species, including ranid frogs
(Hayes and Jennings 1986, p. 497; Boyer and Grue 1995, pp. 353-354;
Hecnar 1995, pp. 2133-2135; Materna et al. 1995, pp. 616-618; NBII
2005; Mann et al. 2009, p. 2904). Exposure to pesticides can lower an
individual's immune function, which increases the risk of disease or
possible malformation (Stark 2005, p. 21; Mann et al. 2009, pp. 2905,
2909). In addition, it has been demonstrated that some chemicals reduce
growth and delay development.
A reduction of growth or development would prolong an individual's
larval period, thus making it more susceptible to predators for a
longer period of time or resulting in immobility during periods of time
when movement between habitats may be necessary (Mann et al. 2009, p.
2906). Many of the described effects from pesticides are sublethal but
ultimately may result in the mortality of the exposed individuals as
described above. Furthermore, the results of several studies have
suggested that, while the impacts of individual chemicals on amphibians
are sublethal, a combination or cocktail of a variety of chemicals may
be lethal (Mann et al. 2009, p. 2913; Bishop et al. 2010, p. 1602). The
use of pesticides may be occurring throughout the range of the Oregon
spotted frog due to the species' overlap with agricultural and urban
environments; however, information regarding the extent, methods of
application, and amounts applied is not available. Therefore, we are
unable to make an affirmative determination at this time that
pesticides are a threat.
There are two agents commonly used for mosquito abatement within
the range of Oregon spotted frog: Bacillus
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thuringiensis var. israelensis (Bti) and methoprene. Bti is a bacterial
agent that has no record of adverse direct effects on amphibians, but
methoprene has been historically linked to abnormalities in southern
leopard frogs (Lithobates utricularia), including completely or
partially missing hind limbs, discoloration, and missing eyes. Missing
eyes and delayed development in northern cricket frogs (Acris
crepitans) have also been linked to methoprene (Stark 2005, p. 20).
However, a recent scientific literature review suggests that methoprene
is not ultimately responsible for frog malformations (Mann et al. 2009,
pp. 2906-2907). The findings of this review suggest that, in order for
malformations to occur, the concentration of methoprene in the water
would induce mortality (Mann et al. 2009, p. 2906).
We also evaluated the indirect effect that Bti and methoprene may
have on Oregon spotted frogs by reducing their insect prey species.
When used for mosquito abatement, both Bti and methoprene most strongly
affect flies belonging to the suborder Nematocera (the thread-horned
flies), which includes mosquitos, but may also other chironomid flies
such as non-biting midges (Chironomidae) (Hershey et al. 1998, p. 42;
Lawler et al. 2000, p. 177; Rochlin et al. 2011, pp. 11-13). We
compiled information on the number of insect orders recorded as present
during stomach content studies (Licht 1986a, p. 28; Pearl and Hayes
2002, pp. 145-147; Pearl et al. 2005a, p. 37) and then examined the
proportion of the order (diptera; flies) primarily affected by Bti and
methoprene in relation to the rest of the recorded diet of the Oregon
spotted frog. While there are not many data to consider, the kinds of
flies most commonly affected compose a small portion of the overall
diet of the Oregon spotted frogs that were included in the stomach
content studies. We conclude that Bti and methoprene, applied as
recommended for mosquito control, are likely to have a negligible
effect on Oregon spotted frogs due to the diversity of the species'
diet. This is our conclusion for this species only. We do not assume
that these agents could not present a threat to other species of frogs
that are more dependent on the nematoceran diptera that Bti and
methoprene do negatively affect. Therefore, based on the best available
information, we do not consider Bti or methoprene to be a threat to
Oregon spotted frogs.
Although the effects on amphibians of rotenone, which is used to
remove undesirable fish from lakes, are poorly understood, mortality
likely occurs at treatment levels used on fish (McAllister et al. 1999,
p. 21). The role of rotenone treatments in the disappearance of Oregon
spotted frogs from historical sites is unknown; however, some studies
indicate that amphibians might be less sensitive than fish and might be
capable of recovering from exposure to rotenone (Mullin et al. 2004,
pp. 305-306; Walston and Mullin 2007, p. 65). However, these studies
did not measure the effects on highly aquatic amphibians, like the
Oregon spotted frog. In fall of 2011, the ODFW used rotenone to remove
goldfish from a small pond adjacent to Crane Prairie Reservoir. In
April 2012, approximately 40 spotted frog egg masses were located in
the pond, where there had been no prior record of Oregon spotted frog
occupancy in the past (Wray 2012, pers. comm.). No rotenone treatments
in Cascade lakes occupied by Oregon spotted frog are planned in the
near future (Hodgson 2012, pers. comm.), and to date, in the Upper
Klamath Lake sub-basin, no fish killing agents have been applied within
Oregon spotted frog habitat (Banish 2012, pers. comm.). Therefore,
based on the best available information, we do not consider rotenone to
be a threat to Oregon spotted frogs.
Water acidity (low pH) can inhibit fertilization and embryonic
development in amphibians, reduce their growth and survival through
physiological alterations, and produce developmental anomalies (Hayes
and Jennings 1986, pp. 498-499; Boyer and Grue 1995, p. 353). A low pH
may enhance the effects of other factors, such as activating heavy
metals in sediments. An elevated pH, acting singly or in combination
with other factors such as low dissolved oxygen, high water
temperatures, and elevated un-ionized ammonia levels, may have
detrimental effects on developing frog embryos (Boyer and Grue 1995, p.
354). Concerns about pH levels have been identified in sub-basins
occupied by the Oregon spotted frog.
Required dissolved oxygen levels for Oregon spotted frogs have not
been evaluated; however, a number of studies have been conducted on
amphibians that indicate that the amount of dissolved oxygen can affect
all life stages. Low oxygen levels can affect the rate of egg
development, time to hatching, and development stage at hatching. For
example, Mills and Barnhart (1999, p. 182) found that embryos of two
salamanders developed more slowly and hatching was delayed. In
contrast, in two ranid frog species, low oxygen levels resulted in
embryos hatching sooner and in a less developed stage (Mills and
Barnhart 1999, p. 182). As dissolved oxygen levels decreased below 4.0
to 4.25 parts per million, Wassersug and Seibert (1975, pp. 90-93),
found tadpoles of Rana pipiens and Bufo woodhousii swam to the surface
(not a normal behavior), and all remained at the surface at levels
below 2.0 parts per million. Similarly, Moore and Townsend (1998, p.
332) found that decreasing oxygen levels increased the number of times
Rana clamitans tadpoles surfaced and the amount of time spent at the
surface. This behavior increased the risk of predation because
signficantly more Rana clamitans tadpoles were eaten when mean oxygen
levels were at or below 2.7 mg/L (Moore and Townsend 1998, p. 332).
Ranid species have been found to use overwintering microhabitat with
well-oxygenated waters (Ultsch et al. 2000, p. 315; Lamoureux and
Madison 1999, p. 434), although some evidence indicates that Oregon
spotted frogs can tolerate levels at or somewhat below 2.0 mg/L during
the winter for short periods (Hayes et al. 2001, pp. 20-22; Risenhoover
et al. 2001b, pp. 17-18).
Marco et al. (1999, p. 2838) demonstrated the strong sensitivity of
Oregon spotted frog tadpoles to nitrate and nitrite ions in laboratory
experiments, and suggested that nitrogen-based chemical fertilizers may
have contributed to the species' decline in the lowland areas of its
distribution. This research suggests that the recommended maximum
levels of nitrates (10 milligrams/Liter (mg/L)) and nitrites (1 mg/L)
in drinking water are moderately to highly toxic for Oregon spotted
frogs, indicating that EPA water quality standards do not protect
sensitive amphibian species (Marco et al. 1999, p. 2838). In the Marco
et al. study, Oregon spotted frog tadpoles did not show a rapid adverse
effect to nitrate ions, but at day 15 of exposure they reflected high
sensitivity followed by synchronous death. Many public water supplies
in the United States contain levels of nitrate that routinely exceed
concentrations of 10 mg/L of nitrate; the median lethal concentrations
for aquatic larvae of the Oregon spotted frog is less than 10 mg/L
(Marco et al. 1999, p. 2838). Grazing is one source of nitrates and
nitrites; according to the EPA, the major sources of nitrates in
drinking water are runoff from fertilizer use, leaking from septic
tanks and sewage, and erosion of natural deposits. Most currently known
occupied sites for Oregon spotted frog are located in areas where
residential septic tanks are used and farming practices include
fertilizer application and grazing.
[[Page 51690]]
Elevated sources of nutrient inputs into river and wetland systems
can result in eutrophic (nutrient-rich) conditions, characterized by
increased productivity, such as blooms of algae, that can produce a
high pH and low dissolved oxygen. Increased eutrophic conditions in the
Upper Klamath Lake sub-basin may have contributed to the absence of
Oregon spotted frogs. Beginning in 2002, algal blooms, poor water
quality, and low dissolved oxygen were documented in Jack Creek, during
which a decline in Oregon spotted frog reproduction was also documented
(Oertley 2005, pers. comm.).
Water quality concerns have been documented in several waterbodies
occupied by the Oregon spotted frog. In Washington, portions of the
Sumas River; Black Slough in the South Fork Nooksack sub-basin;
portions of the Samish River; segments of the Black River; segments of
Dempsey, Allen, and Beaver Creeks in the Black River sub-basin; and a
segment in the upper portion of Trout Lake Creek are listed by the WDOE
as not meeting water quality standards for a variety of parameters,
including temperature, fecal coliform, pH, and dissolved oxygen. In
Oregon, many of the streams associated with Oregon spotted frog habitat
are listed by the Oregon Department of Environmental Quality as not
meeting water quality standards for multiple parameters: (1) Little
Deschutes River--temperature, dissolved oxygen, chlorophyll A, pH,
aquatic weeds or algae; (2) Deschutes River--temperature, dissolved
oxygen, turbidity, sedimentation; (3) Middle Fork Willamette River--
sedimentation; (4) Upper Klamath--temperature; and (5) Williamson
River--sedimentation.
In British Columbia, Oregon spotted frogs at Morris Valley,
Mountain Slough, and Maria Slough are in largely agricultural areas.
Agricultural runoff includes fertilizers (including manure); runoff or
percolation into the groundwater from manure piles (Rouse et al. 1999);
and spraying of agricultural chemicals such as pesticides or
insecticides (including Bacillus thuringiensis bacterium) or fungicides
(used by blueberry producers), including wind-borne chemicals. Water-
borne sewage and non-point source runoff from housing and urban areas
that include nutrients, toxic chemicals, and/or sediments may also be
increasing in intensity. Additional sources of contaminants may include
chemical spraying during forestry activities, maintenance of power line
corridors, or disruption of normal movements of nutrients by forestry
activities (Canadian Recovery Strategy (COSFRT) 2012, p. 21). The
COSFRT (2012, p. 17) identifies pollution associated with agricultural
and forestry effluents as being (1) high impact; (2) large in scope;
(3) serious in severity; (4) high in timing; and (5) a stress that has
direct and indirect mortality results. One of the recovery objectives
is to coordinate with the Minister of Agriculture to implement
supporting farming practices and environmental farm plans options to
decrease agrochemical and nutrient pollution into Oregon spotted frog
habitat and work with all levels of government, land managers, and
private landowners to inform and encourage best practices and ensure
compliance in relation to water quality, hydrology, and land use
practice (COSFRS 2012, p. 34).
Although more research is needed, Johnson et al. (2002a; Johnson
and Chase 2004) state that eutrophication associated with elevated
nitrogen (and phosphorus) has been linked with increased snail
populations. Johnson and Chase (2004, p. 522) point to elevated levels
of nutrients (particularly phosphorus) from agricultural fertilizers
and cattle grazing in freshwater ecosystems as causing shifts in the
composition of aquatic snails from small species to larger species.
These larger species serve as intermediate hosts for a parasite
(Ribeiroia ondatrae), which causes malformations in amphibians (see
``Disease'' under Factor C discussion, above).
Water quality and contamination conclusion--Although pesticides are
known to affect various life stages of the Oregon spotted frog, the
impact of this potential threat is undetermined at this time. We do not
consider rotenone or methoprene to be threats to the species.
Oregon spotted frogs are highly aquatic throughout their life
cycle, and are thus likely to experience extended exposure to any
waterborne contaminants. Poor water quality parameters and contaminants
may act singly or in combination with other factors to result in
inhibited fertilization and embryonic development, developmental
anomalies, or reduced growth and survival. More work on the species'
ecotoxicology is warranted. However, reduced water quality is
documented in a number of occupied sub-basins, and where this overlap
occurs we consider poor water quality and contaminants to be threats to
the Oregon spotted frog.
Hybridization
Hybridization between Oregon spotted frogs and closely related frog
species is unlikely to affect the survival of the Oregon spotted frog.
Natural hybridization between Oregon spotted frogs and Cascade frogs
has been demonstrated experimentally and verified in nature (Haertel
and Storm 1970, pp. 436-444; Green 1985, p. 263). However, the
offspring are infertile, and the two species seldom occur together.
Hybridization between Oregon spotted frogs and red-legged frogs has
also been confirmed (I.C. Phillipsen and K. McAllister cited in Hallock
2013, p. 7), but it is unknown if the hybrids are fertile. Because
Oregon spotted frog and Columbia spotted frog populations are not known
to occur together, based on the best available information, we do not
consider hybridization to be a threat to Oregon spotted frogs.
Climate Change
Our analyses under the Act include consideration of ongoing and
projected changes in climate. The terms ``climate'' and ``climate
change'' are defined by the Intergovernmental Panel on Climate Change
(IPCC). The term ``climate'' refers to the mean and variability of
different types of weather conditions over time, with 30 years being a
typical period for such measurements, although shorter or longer
periods also may be used (IPCC 2007a, p. 78). The term ``climate
change'' thus refers to a change in the mean or variability of one or
more measures of climate (e.g., temperature or precipitation) that
persists for an extended period, typically decades or longer, whether
the change is due to natural variability, human activity, or both (IPCC
2007a, p. 78).
Scientific measurements spanning several decades demonstrate that
changes in climate are occurring, and that the rate of change has been
faster since the 1950s. Examples include warming of the global climate
system, and substantial increases in precipitation in some regions of
the world and decreases in other regions. (For these and other
examples, see IPCC 2007a, p. 30; Solomon et al. 2007, pp. 35-54, 82-
85). Results of scientific analyses presented by the IPCC show that
most of the observed increase in global average temperature since the
mid-20th century cannot be explained by natural variability in climate,
and is ``very likely'' (defined by the IPCC as 90 percent or higher
probability) due to the observed increase in greenhouse gas (GHG)
concentrations in the atmosphere as a result of human activities,
particularly carbon dioxide emissions from use of fossil fuels (IPCC
2007a, pp. 5-6 and figures SPM.3 and SPM.4; Solomon et al. 2007, pp.
21-35). Further confirmation of the role of GHGs comes from analyses by
Huber and Knutti (2011, p. 4), who concluded it is extremely likely
that approximately 75
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percent of global warming since 1950 has been caused by human
activities.
Scientists use a variety of climate models, which include
consideration of natural processes and variability, as well as various
scenarios of potential levels and timing of GHG emissions, to evaluate
the causes of changes already observed and to project future changes in
temperature and other climate conditions (e.g., Meehl et al. 2007,
entire; Ganguly et al. 2009, pp. 11555, 15558; Prinn et al. 2011, pp.
527, 529). All combinations of models and emissions scenarios yield
very similar projections of increases in the most common measure of
climate change, average global surface temperature (commonly known as
global warming), until about 2030. Although projections of the
magnitude and rate of warming differ after about 2030, the overall
trajectory of all the projections is one of increased global warming
through the end of this century, even for the projections based on
scenarios that assume that GHG emissions will stabilize or decline.
Thus, strong scientific data support projections that warming will
continue through the 21st century, and that the magnitude and rate of
change will be influenced substantially by the extent of GHG emissions
(IPCC 2007a, pp. 44-45; Meehl et al. 2007, pp. 760-764, 797-811;
Ganguly et al. 2009, pp. 15555-15558; Prinn et al. 2011, pp. 527, 529).
(See IPCC 2007b, p. 8, for a summary of other global projections of
climate-related changes, such as frequency of heat waves and changes in
precipitation. Also see IPCC 2012 (entire) for a summary of
observations and projections of extreme climate events.)
Various changes in climate may have direct or indirect effects on
species. These effects may be positive, neutral, or negative, and they
may change over time, depending on the species and other relevant
considerations, such as interactions of climate with other variables
(e.g., habitat fragmentation) (IPCC 2007, pp. 8-14, 18-19). Identifying
likely effects often involves aspects of climate change vulnerability
analysis. Vulnerability refers to the degree to which a species (or
system) is susceptible to, and unable to cope with, adverse effects of
climate change, including climate variability and extremes.
Vulnerability is a function of the type, magnitude, and rate of climate
change and variation to which a species is exposed, its sensitivity,
and its adaptive capacity (IPCC 2007a, p. 89; see also Glick et al.
2011, pp. 19-22). No single method for conducting such analyses applies
to all situations (Glick et al. 2011, p. 3). We use our expert judgment
and appropriate analytical approaches to weigh relevant information,
including uncertainty, in our consideration of various aspects of
climate change.
As is the case with all stressors that we assess, even if we
conclude that a species is currently affected or is likely to be
affected in a negative way by one or more climate-related impacts, the
species does not necessarily meet the definition of an ``endangered
species'' or a ``threatened species'' under the Act. If a species is
listed as an endangered or threatened species, knowledge regarding the
vulnerability of the species to, and known or anticipated impacts from,
climate-associated changes in environmental conditions can be used to
help devise appropriate strategies for its recovery.
Global climate projections are informative, and, in some cases, the
only or the best scientific information available for us to use.
However, projected changes in climate and related impacts can vary
substantially across and within different regions of the world (e.g.,
IPCC 2007a, pp. 8-12). Therefore, we use ``downscaled'' projections
when they are available and have been developed through appropriate
scientific procedures, because such projections provide higher
resolution information that is more relevant to spatial scales used for
analyses of a given species (see Glick et al. 2011, pp. 58-61, for a
discussion of downscaling). With regard to our analysis for the Oregon
spotted frog, downscaled projections are available.
The climate in the PNW has already experienced a warming of 0.8
degrees Celsius (C) (1.4 degrees Fahrenheit (F)) during the 20th
century (Mote et al. 2008, p. 3). Using output from eight climate
models, the PNW is projected to warm further by 0.6 to 1.9 degrees C
(1.1 to 3.4 degrees F) by the 2020s, and 0.9 to 2.9 degrees C (1.6 to
5.2 degrees F) by the 2040s (Mote et al. 2008, pp. 5-6). Additionally,
the majority of models project wetter winters and drier summers (Mote
et al. 2008, p. 7), and of greatest consequence, a reduction in
regional snowpack, which supplies water for ecosystems during the dry
summer (Mote et al. 2003). The small summertime precipitation increases
projected by a minority of models do not change the fundamentally dry
summers of the PNW and do not lessen the increased drying of the soil
column brought by higher temperatures (Mote et al. 2003, p. 8).
Watersheds that are rain dominated (such as the Fraser River in
British Columbia and the Black River in Washington) will likely
experience higher winter streamflow because of increases in average
winter precipitation, but overall will experience relatively little
change with respect to streamflow timing (Elsner et al. 2010, p. 248).
Water temperatures for western Washington are generally cooler than
those in the interior Columbia basin; however, climate change
predictions indicate the summertime stream temperatures exceeding 19.5
degrees C (67.1 degrees F) will increase, although by a smaller
fraction than the increases in the interior Columbia basin (Mantua et
al. 2010, p. 199).
Transient basins (mixed rain- and snowmelt-dominant usually in mid
elevations, such as Lower Chilliwack, SF Nooksack, White Salmon, and
Middle Klickitat Rivers sub-basins in Washington) will likely
experience significant shifts in streamflow and water temperature,
becoming rain dominant as winter precipitation falls more as rain and
less as snow, and undergo more severe summer low-flow periods and more
frequent days with intense winter flooding (Elsner et al. 2010, pp.
248, 252, 255; Mantua et al. 2010, entire).
Snowmelt-dominated watersheds, such as White Salmon in Washington
and the Upper Deschutes, Little Deschutes, and Klamath River sub-basins
in Oregon, will likely become transient, resulting in reduced peak
spring streamflow, increased winter streamflow, and reduced late summer
flow (Littell et al. 2009, p. 8). In snowmelt-dominated watersheds that
prevail in the higher altitude catchments and in much of the interior
Columbia Basin, flood risk will likely decrease and summer low flows
will decrease in most rivers under most scenarios (Littell et al. 2009,
p. 13).
In Washington, the snow water equivalent measured on April 1 is
projected to decrease by 28 to 30 percent across the State by the
2020s, 38 to 46 percent by the 2040s, and 56 to 70 percent by the
2080s, and the areas with elevations below 3,280 ft (1,000 m) will
experience the largest decreases in snowpack, with reductions of 68 to
80 percent by the 2080s (Elsner et al. 2010, p. 244). In the Puget
Trough sub-basins, summertime soil moisture will decrease as a result
of the warming climate and reduced snowpack. While annual precipitation
is projected to slightly increase across the State, by 3.4 percent by
the 2080s, the seasonality of the precipitation will change more
dramatically with increased winter and decreased summer precipitation,
with most of the precipitation falling between
[[Page 51692]]
October and March (Elsner et al. 2010, p. 247).
Climate change models predict that water temperatures will rise
throughout Oregon as air temperatures increase into the 21st century. A
decline in summer stream flow may exacerbate water temperature
increases as the lower volume of water absorbs solar radiation (Chang
and Jones 2010, p. 134).
Analyses of the hydrologic responses of the upper Deschutes basin
(including the Upper and Little Deschutes River sub-basins) and the
Klamath Basin to climate change scenarios indicates that the form of
precipitation will shift from predominately snow to rain and cause
decreasing spring recharge and runoff and increasing winter recharge
and runoff (Waibel 2011, pp. 57-60; Mayer and Naman 2011, p. 3).
However, there is spatial variation within the Deschutes sub-basins as
to where the greatest increases in recharge and runoff will occur
(Waibel 2011, pp. 57-60). Changes in seasonality of stream flows may be
less affected by climate change along the crest of the Cascades in the
upper watersheds of the Deschutes, Klamath, and Willamette River basins
in Oregon, where many rivers receive groundwater recharge from
subterranean aquifers and springs (Chang and Jones 2010, p. 107).
Summer stream flows may thus be sustained in high Cascade basins that
are groundwater fed (Chang and Jones 2010, p. 134). Conversely, Mayer
and Naman (2011, p. 1) indicate that streamflow into Upper Klamath Lake
will display absolute decreases in July-September base flows in
groundwater basins as compared to surface-dominated basins. This
earlier discharge of water in the spring will result in less streamflow
in the summer (Mayer and Naman 2011, p. 12).
Although predictions of climate change impacts do not specifically
address Oregon spotted frogs, short- and long-term changes in
precipitation patterns and temperature regimes will likely affect wet
periods, winter snow pack, and flooding events (Chang and Jones 2010).
These changes are likely to affect amphibians through a variety of
direct and indirect pathways, such as range shifts, breeding success,
survival, dispersal, breeding phenology, availability and quality of
aquatic habitats, food webs, competition, spread of diseases, and the
interplay among these factors (Blaustein et al. 2010, entire; Hixon et
al. 2010, p. 274; Corn 2003, entire). Amphibians have species-specific
temperature tolerances, and exceeding these thermal thresholds is
expected to reduce survival (Blaustein et al. 2010, pp. 286-287).
Earlier spring thaws and warmer ambient temperatures may result in
earlier breeding, especially at lower elevations in the mountains where
breeding phenology is driven more by snow pack than by air temperature
(Corn 2003, p. 624). Shifts in breeding phenology may also result in
sharing breeding habitat with species not previously encountered and/or
new competitive interactions and predator/prey dynamics (Blaustein et
al. 2010, pp. 288, 294). Oregon spotted frogs are highly aquatic, and
reductions in summer flows may result in summer habitat going dry,
potentially resulting in increased mortality or forcing frogs to seek
shelter in lower quality wetted areas where they are more susceptible
to predation.
Amphibians are susceptible to many types of pathogens including
trematodes, copepods, fungi, oomycetes, bacteria, and viruses. Changes
in temperature and precipitation could alter host-pathogen interactions
and/or result in range shifts resulting in either beneficial or
detrimental impacts on the amphibian host (Blaustein et al. 2010, p.
296). Kiesecker et al. (2001a, p. 682) indicate climate change events,
such as El Nino/Southern Oscillation, that result in less precipitation
and reduced water depths at egg-laying sites results in high mortality
of embryos because their exposure to UV-B and vulnerability to
infection (such as Saprolegnia) is increased. Warmer temperatures and
less freezing in areas occupied by bullfrogs is likely to increase
bullfrog winter survivorship, thereby increasing the threat from
predation. Uncertainty about climate change impacts does not mean that
impacts may or may not occur; it means that the risks of a given impact
are difficult to quantify (Schneider and Kuntz-Duriseti 2002, p. 54;
Congressional Budget Office 2005, entire; Halsnaes et al. 2007, p.
129). Oregon spotted frogs occupy habitats at a wide range of
elevations, and all of the occupied sub-basins are likely to experience
precipitation regime shifts; therefore, the Oregon spotted frog's
response to climate change is likely to vary across the range, and the
population-level impacts are uncertain. The interplay between Oregon
spotted frogs and their aquatic habitat will ultimately determine their
population response to climate change. Despite the potential for future
climate change throughout the range of the species, as discussed above,
we have not identified, nor are we aware of any data on, an appropriate
scale to evaluate habitat or population trends for the Oregon spotted
frog or to make predictions about future trends and whether the species
will be significantly impacted.
Conservation Efforts To Reduce Other Natural or Manmade Factors
Affecting Its Continued Existence
The U.S. Department of Agriculture, Animal and Plant Health
Inspection Service (APHIS), maintains voluntary agreements with private
landowners concerning application of pesticides within the United
States. Based on their 2010 operational procedures, all waterbodies
(rivers, ponds, reservoirs, streams, vernal pools, wetlands, etc.) will
be avoided by a minimum of a 50-foot buffer for ground application of
bait, a 200-foot buffer for aerial application of bait, and a 500-foot
buffer for the aerial application of liquids (USDA APHIS 2010, p. 4).
As previously described under other threat factors, conservation
efforts may also help reduce the threat of other natural or manmade
factors affecting the species.
Summary of Other Natural or Manmade Factors
Many of the Oregon spotted frog breeding locations are small and
isolated from other breeding locations. Moreover, due to their fidelity
to breeding locations and vulnerability to fluctuating water levels,
predation, and low overwinter survival, Oregon spotted frogs can
experience rapid population turnovers that they may not be able to
overcome. Genetic work indicates low genetic diversity within and high
genetic differentiation among the six Oregon spotted frog groups
identified by Blouin, and each of these groups has the signature of
complete isolation with two groups showing indications of recent
genetic drift. Poor water quality parameters and contaminants may act
singly or in combination with other factors to result in inhibited
fertilization and embryonic development, developmental anomalies, or
reduced growth and survival. Oregon spotted frogs in every occupied
sub-basin are subject to more than one stressor, such as loss or
reduced quality of habitat and predation and, therefore, may be more
susceptible to mortality and sublethal effects. The changing climate
may exacerbate these stressors. Therefore, based on the best
information available, we conclude that other natural or manmade
factors are a threat to the Oregon spotted frog, which has significant
population effects occurring throughout the entire (current) range of
the species and these effects are expected to continue into the future.
Cumulative Effects From Factors A Through E
The Oregon spotted frog faces several threats, and all occupied
sub-basins are
[[Page 51693]]
subjected to multiple threats, which cumulatively pose a risk to
individual populations (see Table 2, below). Many of these threats are
intermingled, and the magnitude of the combined threats to the species
is greater than the individual threats. For example, the small sizes
and isolation of the majority of Oregon spotted frog breeding locations
makes Oregon spotted frogs acutely vulnerable to fluctuating water
levels, disease, predation, poor water quality, and extirpation from
stochastic events. Hydrologic changes, resulting from activities such
as water diversions and removal of beavers, increase the likelihood of
fluctuating water levels and temperatures, and may also facilitate
predators. Existing regulatory mechanisms facilitate hydrologic
changes, and restoration actions are specifically designed to benefit
salmonid species, which often results in the reduction of habitat
quality and quantity for Oregon spotted frogs where they overlap.
Habitat management and a warming climate may improve conditions for
pathogens and predators. Saprolegnia, Bd, and Ribeiroia ondatrae have
been found in Oregon spotted frogs, and compounded with other
stressors, such as UV-B exposure, degradation of habitat quality, or
increased predation pressure, may contribute to population declines. Bd
and R. ondatrae, in particular, infect post-metamorphic frogs and
reductions in these life stages are more likely to lead to population
declines. Sub-basins projected to transition from snow-dominant or
transient to rain-dominant will be less susceptible to freezing
temperatures with the expectation of reduced mortality of bullfrogs
during winter and increased predation risk to Oregon spotted frogs.
Amphibian declines may frequently be associated with multiple
correlated factors (Adams 1999, pp. 1167-1169). Two of the greatest
threats to freshwater systems in western North America, exotic species
and hydrological changes, are often correlated. In addition, occurrence
and abundance of bullfrogs may be linked with invasions by nonnative
fish (Adams et al. 2003, p. 349; Rowe and Garcia 2014, p. 147). Adams
(1999) examined the relationships among introduced species, habitat,
and the distribution and abundance of red-legged frogs in western
Washington. Red-legged frog occurrence in the Puget lowlands was more
closely associated with habitat structure and exotic fish than with the
presence of bullfrogs (Adams 1999, pp. 1167-1168), and similar
associations were found in a recent study in Oregon's Willamette Valley
(Pearl et al. 2005b, p. 16). Rowe and Garcia (2014, p. 147) found
native anuran counts were consistently lower in wetlands with nonnative
fish, whereas bullfrog counts were higher. The spread of exotic species
is correlated with a shift toward greater permanence in wetland
habitats regionally (for example, Kentula et al. 1992, p. 115). For
example, exotic fish and bullfrogs are associated with permanent
wetlands. Conservation of more ephemeral wetland habitats, which
directly benefit native amphibians such as Oregon spotted frogs, would
be expected to reduce predation and competition threats posed by exotic
fish and bullfrogs (Adams 1999, pp. 1169-1170; Rowe and Garcia 2014, p.
150). However, bullfrogs may be adapting because they have recently
been found successfully breeding in ephemeral wetlands in the
Willamette Valley, Oregon (Cook 2013, p. 656).
Amphibians are affected by complex interactions of abiotic and
biotic factors, and are subjected simultaneously to numerous
interacting stressors. For example, contaminants and UV-B radiation may
result in mortality or induce sublethal effects on their own, but they
may have synergistic, interaction effects that exceed the additive
effects when combined. Some stressors, such as contaminants, may hamper
the immune system, making amphibians more susceptible to pathogenic
infections (Kiesecker 2002, p. 9902). Predator presence can alter the
behavior of amphibians, resulting in more or less exposure to UV-B
radiation (Michel and Burke 2011), thereby altering the rate of
malformations. Climate-driven dry events that result in lower water
levels may concentrate contaminants, as well as increase the amount of
exposure to UV-B radiation. While any one of these individual stressors
may not be a concern, a contaminant added to increased UV-B radiation
exposure and a normally healthy population level of Ribeiroia ondatrae
may lead to a higher mortality rate or an increased number of malformed
frogs that exceeds the rate caused by any one factor alone (Blaustein
et al. 2003, entire; Szurocksi and Richardson 2009 p. 382). Oregon
spotted frogs in every occupied sub-basin are subject to more than one
stressor and, therefore, may be more susceptible to mortality and
sublethal effects.
The historical loss of Oregon spotted frog habitats and lasting
anthropogenic changes in natural disturbance processes are exacerbated
by the introduction of reed canarygrass, nonnative predators, and
potentially climate change. In addition, current regulatory mechanisms
and voluntary incentive programs designed to benefit fish species have
inadvertently led to the continuing decline in quality of Oregon
spotted frog habitats in some locations. The current wetland and stream
vegetation management paradigm is generally a no-management or
restoration approach that often results in succession to a tree- and
shrub-dominated community that unintentionally degrades or eliminates
remaining or potential suitable habitat for Oregon spotted frog
breeding. Furthermore, incremental wetland loss or degradation
continues under the current regulatory mechanisms. If left unmanaged,
these factors are anticipated to result in the eventual elimination of
remaining suitable Oregon spotted frog habitats or populations. The
persistence of habitats required by the species is now largely
management dependent.
Conservation efforts to ameliorate impacts from habitat degradation
and predators are currently under way; however, the benefits of these
conservation actions to Oregon spotted frogs are site-specific and do
not counteract the impacts at a sub-basin scale. The cumulative effects
of these threats are more than additive, and removing one threat does
not ameliorate the others and may actually result in an increase in
another threat. For example, removing livestock grazing to improve
water quality--without continuing to manage the vegetation--can allow
invasive reed canarygrass, trees, and shrubs to grow and effectively
eliminate egg-laying habitat.
Therefore, based on the best scientific information available, we
conclude that the cumulative effects from factors discussed in Factors
A, C, and E, combined with the inadequacy of existing regulatory
mechanisms discussed under Factor D, are a threat to the Oregon spotted
frog, and these threats are significantly affecting populations
throughout the entire range of the species. Moreover, these threats are
expected to continue into the future.
[[Page 51694]]
Table 2--Threats Operating Within Each Sub-Basin *
----------------------------------------------------------------------------------------------------------------
Sub-basin Factor A Factor C Factor E
----------------------------------------------------------------------------------------------------------------
Lower Fraser River.................. Wetland loss; hydrologic Introduced warmwater Small population size;
changes; development; fish; bullfrogs. breeding locations
grazing, reed disconnected;
canarygrass; water contaminants;
quality. cumulative effects of
other threats; climate
change.
Lower Chilliwack River.............. Grazing; reed Introduced warmwater Small population size;
canarygrass; water fish. breeding locations
quality. disconnected;
contaminants;
cumulative effects of
other threats; climate
change.
South Fork Nooksack................. Grazing; reed Introduced coldwater Small population size;
canarygrass; shrub fish. cumulative effects of
encroachment/planting; other threats;
loss of beavers; water contaminants; climate
quality. change.
Samish River........................ Wetland loss; grazing; Introduced warmwater Breeding locations
reed canarygrass; shrub fish; introduced disconnected;
encroachment/planting; coldwater fish. contaminants;
water quality. cumulative effects of
other threats; climate
change.
Black River......................... Wetland loss; reed Introduced warmwater Small population size;
canarygrass; shrub fish; introduced breeding locations
encroachment/planting; coldwater fish; disconnected;
development; loss of bullfrogs. contaminants;
beaver; water quality. cumulative effects of
other threats; climate
change.
White Salmon River.................. Wetland loss; reed Introduced coldwater Cumulative effects of
canarygrass; water fish. other threats; climate
quality. change.
Middle Klickitat River.............. Wetland loss; hydrologic Introduced warmwater Cumulative effects of
changes; loss of fish; introduced other threats; climate
beaver; development; coldwater fish; change.
grazing; reed bullfrogs.
canarygrass; shrub
encroachment; water
management.
Lower Deschutes..................... Shrub encroachment...... ....................... Small population size;
single occupied site
within sub-basin;
isolated from frogs in
other sub-basins;
cumulative effects of
other threats; climate
change.
Upper Deschutes..................... Wetland loss; reed Introduced warmwater Breeding locations
canarygrass; shrub fish; introduced disconnected;
encroachment; coldwater fish, cumulative effects of
hydrological changes bullfrogs. other threats; climate
(water management). change.
Little Deschutes.................... Wetland loss; Introduced coldwater Breeding locations
hydrological changes fish; bullfrogs. disconnected;
(water management); cumulative effects of
development; grazing; other threats; climate
reed canarygrass; shrub change.
encroachment.
McKenzie............................ Shrub encroachment...... Introduced coldwater Only two breeding
fish. locations in sub-
basin, which are
disconnected;
cumulative effects of
other threats; climate
change.
Middle Fork Willamette.............. Shrub encroachment...... Introduced coldwater Single occupied site in
fish. sub-basin;
disconnected from
other sub-basins;
cumulative effects of
other threats; climate
change.
Williamson.......................... Development; grazing; Introduced warmwater Small population size;
shrub encroachment; fish; introduced breeding locations
loss of beaver. coldwater fish. disconnected;
cumulative effects of
other threats; climate
change.
Upper Klamath Lake.................. Water management; Introduced warmwater Small population size;
development; shrub and fish; introduced breeding locations
reed canarygrass coldwater fish; disconnected;
encroachment; grazing. bullfrogs. cumulative effects of
other threats; climate
change.
Upper Klamath....................... Wetland loss; water Introduced warmwater Small population size;
management; fish; introduced breeding locations
development; grazing; coldwater fish. disconnected;
shrub encroachment; cumulative effects of
loss of beaver. other threats; climate
change.
----------------------------------------------------------------------------------------------------------------
* Existing regulatory mechanisms (Factor D) have been insufficient to significantly reduce or remove the threats
to the Oregon spotted frog. Factors A, C, and E are operative within some to several occupied sites within
each sub-basin, to differing degrees. To clarify, these threats apply to locations within each sub-basin, and
do not necessarily apply to the sub-basin in its entirety. Detailed information is available in a rangewide
threats synthesis document, which is available from Washington Fish and Wildlife Office (see ADDRESSES).
[[Page 51695]]
Summary of Comments and Recommendations
In the proposed rule published on August 29, 2013 (78 FR 53582), we
requested that all interested parties submit written comments on the
proposal by October 28, 2013. On September 26, 2013 (78 FR 59334), we
extended the comment period to November 12, 2013. We also contacted
appropriate Federal and State agencies, scientific experts and
organizations, and other interested parties and invited them to comment
on the proposal. Newspaper notices inviting general public comment were
published in The Olympian, the Yakima Herald Republic, The Goldendale
Sentinel, The Bulletin, and the Mail Tribune. As also announced in that
September 26, 2013, document, we held a public hearing in Lacey,
Washington, on October 21, 2013. On September 18, 2013, we held an
Oregon spotted frog workshop in Klamath Falls, Oregon, to provide the
public with information on the species biology and distribution, and
the listing and critical habitat rules. Public meetings were held in
Sunriver and La Pine, Oregon, on December 3 and 4, 2013, respectively.
During the public comment period for the proposed rule, we received
nearly 80 comment letters addressing the proposed listing for the
Oregon spotted frog. During the October 21, 2013, public hearing, five
individuals or organizations made comments on the proposed rule. All
substantive information provided during the comment period has either
been incorporated directly into this final determination or is
addressed below.
Peer Review
In accordance with our peer review policy published on July 1, 1994
(59 FR 34270), we solicited expert opinion from nine knowledgeable
individuals with scientific expertise that included familiarity with
the Oregon spotted frog and its habitats, biological needs, and
threats. We received responses from eight of the peer reviewers.
We reviewed all comments we received from the peer reviewers for
substantive issues and new information regarding the listing of the
Oregon spotted frog. All peer reviewers felt that the proposed rule was
a thorough description of the status of the Oregon spotted frog and
commented that they considered the proposed rule well researched and
well written. Our requests for peer review are limited to a request for
review of the merits of the scientific information in our documents; if
peer reviewers have volunteered their personal opinions on matters not
directly relevant to the science of our status assessment, we do not
respond to those comments here. The peer reviewers provided a number of
recommended technical corrections or edits to the proposed listing of
the Oregon spotted frog. We evaluated and incorporated this information
into this final rule when and where appropriate to clarify this final
listing rule. Eight peer reviewers provided substantive comments on the
proposed listing of the Oregon spotted frog, which we address below.
Comments From Peer Reviewers
(1) Comment: One peer reviewer thought the Service indicated that
the reintroduction site at Joint Base Lewis McChord lacked suitable
habitat and asked that we identify what features of the Oregon spotted
frog's habitat were missing.
Our response: Our discussion concerning the lack of suitable
habitat is in reference to the Nisqually River sub-basin where a number
of historically occupied locations have been affected by development;
we were not referring to the specific location of the reintroductions
at Joint Base Lewis-McChord military reservation, which may contain
suitable habitat.
(2) Comment: One peer reviewer questioned our use of the sub-basin
scale regarding the number of extant sites, rather than using a smaller
scale, such as a 5th-field or 6th-field watershed. The reviewer was
concerned that this may lead the reader to presume that it is the
Service's implicit intention to retain occupancy at the scale of 4th
fields.
Our response: We used the sub-basin scale to broadly summarize the
distribution of the Oregon spotted frog. In Table 1, we have listed the
historical and extant distribution of Oregon spotted frog throughout
the range by sub-basin (4th field) and watershed (5th field), and in
the Population Estimates and Status section we discussed the number of
breeding locations found within each sub-basin. Additionally, when we
constructed our threats matrix (Threats Synthesis Rangewide Analysis),
we conducted our analysis at the 5th- and 6th-field scales and included
a description of all known locations. We then summarized this
information at the sub-basin scale in order to evaluate threats across
the distribution of the species. The threats matrix was provided to
peer reviewers and made available on both http://www.regulations.gov
and the WFWO Web site.
(3) Comment: One peer reviewer questioned the exclusive use of the
2012 population estimates for Washington and suggested we include 2013
population estimates along with population estimates for other years
for each of the monitored populations in order to demonstrate the
annual variability in Oregon spotted frog estimates.
Our response: Annual variation in survey effort, area coverage, and
timing at individual sites have led us to be cautious in comparing
population estimates across years, and we have not relied upon them to
determine trends, except where there was enough consistency between
data sets to do so. The minimum population estimates were provided to
give a general understanding of the number of frogs currently known in
each sub-basin and the disparity between the 15 occupied sub-basins.
The timing of the proposed rule and availability of data prohibited us
from including 2013 survey data. We have updated the sub-basin
information to include 2013 data where the new information expanded the
distribution or significantly changed the minimum population estimate.
In most cases, 2013 survey efforts were not as extensive as those
conducted in 2011 and 2012, and, in some cases, the Service did not
receive 2013 survey data. We have evaluated the 2013 data in our
possession and determined that a change in status from the proposed
rule is not warranted in any of the occupied sub-basins.
(4) Comment: Two peer reviewers questioned some aspects of our
analysis of livestock grazing as a threat. Specifically, one peer
reviewer asked us to categorize the effects of cattle grazing on Oregon
spotted frog habitat into mesic and arid environments, breeding and
non-breeding habitats, season, and cattle densities. In addition, this
peer reviewer questioned our use of the term livestock, instead of
cattle. Another peer reviewer stated that the personal opinions and
biases of individual researchers contribute to seemingly contradictory
conclusions about the compatibility of grazing with the well-being of
the Oregon spotted frog and that speculation may be given more weight
than deserved. In addition, this peer reviewer stated that some of the
negative effects of grazing to Oregon spotted frog and its habitat that
we discussed are not well supported by research or casual observation.
These negative effects include the direct effect of mortality to adult
frogs and eggs from trampling and numerous indirect effects to habitat,
such as water contamination from urine and feces, increases in
[[Page 51696]]
temperature and sediment production, alterations to stream morphology,
effects on prey organisms, and changes to water quality.
Our response: We agree that the issue of grazing is controversial
and the impacts have been posited to be both positive and negative.
However, grazing and the potential impacts are not consistent across
the range of the species. The weight of the evidence for other
amphibian species and the negative impacts of grazing in riparian areas
are well documented (see ``Livestock Grazing'' section under Factor A
discussion). Livestock as a whole break down banks and influence water
quality if allowed unfettered access to waterbodies, and if livestock
are in shallow water areas being used by frogs, trampling can occur. We
agree that the term livestock can mean various animals domesticated so
as to live and breed in a tame condition. We used the term livestock
because at present we have information with specific regard to cattle
and horses as grazers within Oregon spotted frog habitats.
There is little indication that categorizing the effects of grazing
on Oregon spotted frogs in mesic versus arid environments would produce
significantly different results. The purpose and intent of the grazing
is what drives the effects of grazing. For example, if grazing is
employed alongside other habitat management techniques as a method to
maintain open water areas with short vegetation that is suitable for
egg-laying where egg-laying habitat is a limiting factor, then some
water quality degradation, trampling, and bank breakdown may be
acceptable. However, this should not be taken to imply that there are
no negative consequences associated with grazing as a habitat
management technique. In cases where the primary objective of grazing
is cattle production, the methods used may be different than those
techniques employed to maintain or enhance Oregon spotted frog habitat.
The goals, methods, and impacts to Oregon spotted frogs vary on a site-
by-site basis. Our analysis considered both the possible positive and
negative impacts of grazing but our final conclusion is that grazing
presents a threat within the 10 occupied sub-basins where it currently
occurs.
(5) Comment: One peer reviewer commented that our conclusion
regarding malformations related to Planorbella snails was not
adequately supported by the available data, stating that while
trematode-caused malformations in frogs have been found to result in
higher mortality rates than non-infected frogs, causing a negative
effect at the individual level, effects at the population level are
poorly understood.
Our response: We agree that the effects of these parasite-induced
malformations on amphibians, including Oregon spotted frogs, are clear
at the individual scale, but population-level effects remain largely
uninvestigated. However, the viability of populations of pond-breeding
amphibians is most vulnerable to losses of juveniles and adults when
compared to losses of other life-history stages (Biek et al. 2002, p.
731). As these parasite-induced malformations primarily impact the
survival of juveniles, it is logical to infer that where these
parasites co-occur with Oregon spotted frogs and infect juveniles, the
viability of Oregon spotted frog populations at those locations is
likely to be negatively affected. We have amended our text to explain
this conclusion. However, as indicated in Summary of Factors Affecting
the Species, we have no information indicating that population declines
in Oregon spotted frogs are occurring as a result of trematode-caused
malformations. Disease continues to be a concern, but more information
is needed to determine the severity of impact that diseases may have on
Oregon spotted frogs. Therefore, under Factor C, we concluded that the
best scientific information indicates that disease is not a threat to
the Oregon spotted frog.
(6) Comment: One peer reviewer commented that our statements
regarding water quality are using standards applied for human
consumption and may not apply to the suitability of a waterbody to
provide quality habitat for the Oregon spotted frog. He agreed with our
statement that many Oregon streams do not meet the Oregon Department of
Environmental Quality's water quality standards and believes this
situation can be interpreted in at least two ways: That water quality
is threatening frog populations in many Oregon streams, or that Oregon
spotted frogs are capable of surviving and may in fact favor water
quality conditions perceived to be poor by human standards.
Our response: We agree that not all water quality parameters are
equal and the standards applied for humans may or may not be
detrimental to Oregon spotted frogs. However, many of the parameters
that we identified in association with water quality, such as pH and
dissolved oxygen, are applicable, as is temperature when it results in
algal blooms and low oxygen levels. Reduced water quality is documented
in a number of occupied sub-basins (see Factor E discussion), and where
this overlap occurs we consider poor water quality and contaminants to
be threats to the Oregon spotted frog.
(7) Comment: One peer reviewer indicated the Oregon spotted frog's
sensitivity to nitrate and nitrite, as presented by Marco et al.
(1999), sounds alarming and recommended we revise the text. The peer
reviewer also commented that the median lethal concentrations of
nitrate and nitrite determined by Marco et al. (1999) was 1,000-fold
the levels he observed in Oregon spotted frog breeding sites from
grazing by cows at a dairy farm in Washington.
Our response: The maximum recommended level for nitrates in
drinking water or for water containing warm-water fishes, as set by the
EPA, exceeds the median lethal concentration for Oregon spotted frog
larvae in laboratory studies, as documented by Marco et al. (1999, p.
2838), which was less than 10 mg/L. It is possible that waterways that
do not exceed the drinking water quality standard could negatively
impact Oregon spotted frogs; however, more field-based studies are
needed to evaluate these impacts. Grazing is only one source of
nitrates and nitrites; the EPA Web site lists the major sources of
nitrates in drinking water to be runoff from fertilizer use, leaking
from septic tanks and sewage, and erosion of natural deposits. Most
currently known occupied sites for Oregon spotted frog are located in
areas where residential septic tanks are used and farming practices
include fertilizer application and grazing. We have revised the text in
the water quality section to acknowledge the ``maximum'' levels as
being toxic to amphibians and provided the maximum limits as set by EPA
for human drinking water.
(8) Comment: One peer reviewer indicated our information regarding
the number of breeding locations below the Wickiup Reservoir was
inaccurate; we indicated there were four breeding areas, but the peer
reviewer stated there were at least six.
Our response: In riverine wetlands along the Deschutes River below
Wickiup Dam there are at least five known breeding locations, including
a new location in La Pine State Park found in 2013. Dilman Meadow is
within the Upper Deschutes River sub-basin but not along the Deschutes
River below Wickiup Dam. The Crosswater population is included within
the Little Deschutes River sub-basin, at the confluence of the
Deschutes River. Language regarding the number and
[[Page 51697]]
distribution of the known Oregon spotted frogs in the Upper Deschutes
River sub-basin has been revised.
(9) Comment: One peer reviewer stated that while he agreed that
most Oregon spotted frog populations are relatively small, isolated,
and vulnerable to factors that may cause population extirpation, he did
not believe that the listing proposal adequately supported climate
change or contaminants as being significant threats.
Our response: In our proposed rule, we concluded that because
Oregon spotted frogs occupy habitats at a wide range of elevations, and
all of the occupied sub-basins are likely to experience precipitation
regime shift, the Oregon spotted frog's response to climate change is
likely to vary across the range and the population-level impacts are
uncertain. We currently do not have the data to determine whether the
species will be significantly impacted by climate change, and this
final rule reflects that position. We reviewed our analysis in the
proposed rule pertaining to threats associated with water quality and
have revised our conclusion about the extent of this threat. Reduced
water quality is documented in a number of occupied sub-basins, and
where this overlap occurs we consider poor water quality and
contaminants to be threats to the Oregon spotted frog.
(10) Comment: One peer reviewer indicated that we should have
included the potential threat from manmade barriers to seasonal
movements by Oregon spotted frogs because these barriers may prevent
frog movement to and from breeding sites or other habitats.
Our response: We agree with the peer reviewer that these manmade
barriers could pose a threat to local populations. In Washington,
impassable culverts have been identified as an issue in relation to
migration of salmon species to or from spawning habitat. Among the
culverts identified by Washington Department of Transportation (WSDOT)
in relation to a lawsuit involving salmon migration, only four come
within 500 ft (153 m) of areas identified as occupied by the Oregon
spotted frog. Two of these occur in the Samish River sub-basin and two
in the South Fork Nooksack River sub-basin. All four of these are on
tributaries that are not known to be used by Oregon spotted frogs and
that are not known to occur between potential breeding habitat and
summer/dry season habitat. Therefore, it does not appear that the
culverts identified under this process pose a threat to Oregon spotted
frogs. However, outside of salmon migration areas in Washington and
throughout Oregon, we do not have the information to evaluate the
number and distribution of manmade barriers; thus at this time, we are
unable to evaluate the severity of this threat. We have added text to
the ``Hydrological Changes'' section under the Factor A discussion in
this rule to reflect the potential of manmade barriers to hinder frog
movement.
(11) Comment: One peer reviewer pointed out that our statement
regarding the potential for hydrologic connectivity and movement
between populations in the Klamath Lake populations does not take into
consideration the potential for Oregon spotted frogs to move during
flood events, through the extensive ditch system within the Wood River
Valley, or between the west side and east side breeding complexes. In
addition, the peer reviewer pointed out that while the sample size was
small, Robertson's and Funk's (2012) reported evidence of gene flow
between the Wood River and Fourmile Creek indicates that there is
movement between populations on the west and east sides of the Wood
River Valley.
Our response: While there is evidence of some genetic exchange
between the west (Fourmile Creek) and east (Wood River) sides of Upper
Klamath Lake, Robertson and Funk (2012, p. 5) indicate the sampling
sites within the two clusters (H and I) are geographically isolated,
indicating limited mixing among sites. Genetic exchange is extremely
low beyond 6 mi (10 km) (Blouin et al. 2010, pp. 2186, 2188), and the
closest distance between currently known breeding areas in Fourmile
Creek and Wood River is greater than 4 mi. Movement by Oregon spotted
frogs during high water events would not constitute a true hydrologic
connection that enables regular or semi-regular dispersal across the
Upper Klamath Lake. High water events are unlikely to frequently
connect these areas due to roads and dikes that separate these two
areas. Additionally, the intersecting area is mostly comprised of ranch
land and water typically does not enter the area due to manipulation of
water levels. Therefore, we continue to consider the sites in the Upper
Klamath Lake sub-basin to be isolated.
(12) Comment: One peer reviewer indicated the 2012 egg mass counts
at Maria Slough in British Columbia increased over those conducted in
previous years, suggesting the apparent decline in the mid-2000s may
have been attributable to a population cycle and/or the result of
excessive flooding in some years that reduced suitable breeding sites
in those years. The reviewer recommended we revise the status from
``declining'' to ``likely stable'' and suggested that the Maria Slough
population is probably exhibiting typical high and low population
cycles often seen in amphibian populations.
Our response: While we agree that amphibian populations may exhibit
typical high and low cycles, which can be attributed to a wide variety
of factors, such as extreme flooding or low-water events that limit
egg-laying locations, the Oregon spotted frog population at Maria
Slough has been supplemented over many years with frogs through the
captive rearing program and these frogs were expected to mature to
breeding age in 2010-2011 (COSEWIC 2011, p. 32). This supplementation
may account for the increase in egg mass numbers in 2012. We have
determined that the recent increases in egg mass counts do not warrant
a change in population status to that of ``stable'' given an estimated
28 percent likelihood of Oregon spotted frogs inhabiting the site by
2050 (COSEWIC 2011, p. 32).
(13) Comment: One peer reviewer cautioned that inference drawn from
many Oregon spotted frog life-history studies should not be
extrapolated globally due to the tendency for these studies to be site-
specific and not representative of site-to-site variation.
Our response: We agree that caution should be exercised in using
site-specific data; to address this concern the information presented
in the life history section describes the variation across the range
(latitude and elevation), including British Columbia south to the
Klamath Basin. Many of the references used in the Life History section
of this rule represent syntheses of information, such as McAllister and
Leonard 1997, Leonard et al. 1993, and Hayes 1994. Within the Summary
of Factors Affecting the Species section, we used the best available
information. In many cases the response by frogs to a stressor is not
widely studied, and the results must be extrapolated across the range.
While stressors will vary across the range of the species, it is
reasonable to assume that the response will not; therefore we have
applied our best professional judgment where it has been necessary to
bridge the gap.
(14) Comment: One peer reviewer suggested we acknowledge
uncertainty around the egg mass counts representing a count of adults.
He provided one anecdotal observation of a female caught in a spawned
out condition that was followed and recaptured several weeks later and
was described on the capture form as gravid and appearing to be ready
to lay another clutch.
[[Page 51698]]
Our response: Phillipsen et al. (2009, p. 7) found that Oregon
spotted frogs in their study area conformed to the assumption that a
female lays only one egg mass per season. However, we have revised the
text to include the additional uncertainty regarding the number of
clutches per female per year.
(15) Comment: One peer reviewer commented that we had not made it
clear how the assumed loss of historical range (up to 90 percent of the
species' former range) was used in our listing determination and
believed that multiple references to the estimated loss of the
historical range may mislead the reader by implying that the range loss
itself constitutes a threat.
Our response: The estimate of historical range loss is referenced
in several places in this rule and is presented to explain to the
reader the extent of the loss of the species across its historical
range. Additionally, our evaluation of the historical threats to the
Oregon spotted frog informs our analysis of the species' response to
current or future threats as summarized under Summary of Factors
Affecting the Species. In the Determination section, we synthesize our
evaluation of past, present, and future threats to the Oregon spotted
frog in order to determine whether the species warrants listing based
on current and future threats.
(16) Comment: One peer reviewer asked whether recreation should be
considered a threat and gave examples of having observed indiscriminate
amphibian egg mass collection and random shooting of frogs by members
of the public.
Our response: In Washington, only one area (Trout Lake Creek)
experiences recreational use due to nearby Federal and private
campgrounds. Most Federal and State lands within currently known Oregon
spotted frog areas have limited access. Most other occupied lands are
privately owned. Oregon spotted frogs are a cryptic species, staying
near and in the water and diving under vegetation to take cover when
disturbed. Therefore, they are seen less often than most species, which
reduces the likelihood for collection or killing of adults, though
their egg masses may be vulnerable where broad public access occurs in
conjunction with breeding sites. Recreation has not been identified as
a threat to the frog in the Deschutes Basin; although Oregon spotted
frogs occur within lakes and rivers that receive recreational use on
National Forests in this basin, there is limited access to the marshes
inhabited by the frog. In the Klamath Basin area of Oregon, recreation
is not known to be threat. We note the peer reviewer's concerns, but
have no other information that would lead us to determine that
recreation may be a threat to the species.
Comments From States
Section 4(i) of the Act states, ``the Secretary shall submit to the
State agency a written justification for [her] failure to adopt
regulations consistent with the agency's comments or petition.''
Comments we received from States regarding the proposal to list the
Oregon spotted frog are addressed below. We received comments from
WDFW, WDNR, WSDOT, WDOE, and Oregon State Department of Transportation
related to biological information, threats, and the inadequacy of
regulatory mechanisms. The agencies provided a number of
recommendations for technical corrections or edits to the proposed
listing of the Oregon spotted frog. We have evaluated and incorporated
this information where appropriate to clarify this final rule. In
instances where the Service may have disagreed with an interpretation
of the technical information that was provided, we have responded to
the State directly.
(17) Comment: We received requests from several State agencies as
well as from public commenters about the development of a rule under
section 4(d) of the Act to provide incidental take exemptions for
various activities. The activities for which coverage was requested
include: Irrigation district activities; grazing; agricultural
diversions and drainage; groundwater pumping; agricultural activities;
road maintenance; dredging of ditches; vegetation management;
development; stormwater management; habitat restoration; research; and
monitoring.
Our response: Whenever any species is listed as a threatened
species, the Service may develop a rule under section 4(d) of the Act
that exempts take under certain conditions. This exemption from take
under a 4(d) rule could include provisions that are tailored to the
specific conservation needs of the threatened species and may be more
or less restrictive than the general prohibitive provisions detailed at
50 CFR 17.31.
We considered the development of a 4(d) rule that would exempt take
of Oregon spotted frogs when that take was incidental to implementing
State, regional, or local comprehensive Oregon spotted frog
conservation programs. We also considered exempting all activities and
efforts conducted by individual landowners on non-Federal lands that
are consistent with maintaining or advancing the conservation of Oregon
spotted frog, but fall outside of a more structured conservation plan.
We further considered exemption from take on lands that are managed
following technical guidelines that have been determined by the Service
to provide a conservation benefit to the Oregon spotted frog, such as
the mowing of reed canarygrass. We requested specific information that
would provide us a high level of certainty that such a program would
lead to the long-term conservation of Oregon spotted frogs (see
Consideration of a 4(d) Special Rule in the August 29, 2013, proposed
listing rule).
Although we received several requests for activities to include in
a 4(d) rule, except as noted below, we did not receive specific
information such as technical guidelines or conservation plans that may
have allowed us to determine that a 4(d) rule exempting take for those
activities would be necessary and advisable to provide a conservation
benefit to the Oregon spotted frog. Some of the activities, such as
irrigation, grazing, agricultural diversions, groundwater pumping
(hydrologic changes), development, and certain vegetation management
methods, for which consideration of a 4(d) rule was requested, are
primary threats to the continued existence of the species. We did not
receive specific information from requesters that would allow us to
determine that a 4(d) rule for these activities would provide a
conservation benefit to the Oregon spotted frog; therefore, an
exception to the prohibition of take of the species due to these
activities is not appropriate. For many of these activities, incidental
take is more appropriately addressed through the development of a
habitat conservation plan (HCP) or, if a Federal nexus exists, through
consultation with the Service under section 7 of the Act. Other
activities, such as haying and some vegetation management methods (such
as mowing of reed canarygrass or installation of barrier cloth), are
not anticipated to result in take of the Oregon spotted frog if these
activities include appropriate conservation measures and occur when
frogs are not known to be present; therefore, consideration of a 4(d)
rule exempting incidental take for these activities is not necessary.
Additionally, management activities vary greatly across the range of
the species, and without specific technical guidelines or conservation
plans we are unable to determine the conservation value of these
activities to the Oregon spotted frog.
We received technical guidelines pertaining to road maintenance;
associated roadside vegetation
[[Page 51699]]
management; and ditch, culvert, and stormwater pond maintenance
activities in Washington. However, we are aware that because a federal
nexus exists for some of these activities, they will be covered, as
appropriate, under a future programmatic section 7 consultation. Also,
in most cases, the stormwater ponds mentioned are disconnected from
permanent water sources, and we are not aware of Oregon spotted frogs
using these types of ponds; therefore, no take is expected. Based on
the information provided by the WSDOT, there is very little overlap
between their activities and Oregon spotted frogs. As described, their
activities could be either beneficial or detrimental to Oregon spotted
frogs, and these activities would be better addressed through other
conservation tools, such as section 7 consultation or HCPs. We will
continue to work with the WSDOT and counties to determine the most
appropriate coverage for activities that will not be covered under
section 7 consultation.
We also received a request for a 4(d) rule from the Oregon
Department of Transportation based on their ``Routine Road Maintenance:
Water Quality and Habitat Guide Best Management Practices.'' The best
management practices (BMPs) found in these guidelines for aquatic
species are specific to Pacific salmon and steelhead. Although these
BMPs avoid and minimize adverse effects to aquatic systems to the
extent practicable, there are no specific criteria to protect
amphibians. For example, the BMPs for beaver dam removal would need to
be modified because Oregon spotted frogs can be dependent on beaver
activity to create and maintain suitable habitat. We would like to work
with the Oregon Department of Transportation to incorporate BMPs that
will avoid and minimize impacts to the Oregon spotted frog.
The Deschutes County Roads Department also submitted comments
requesting a 4(d) rule for road maintenance and operations, including
BMPs for facilities within or near riparian areas. We did not receive
specific information on the County's BMPs that would allow us to
determine that a 4(d) rule for these activities would provide a
conservation benefit to Oregon spotted frog. Therefore, we will
continue to work with the Deschutes County Road Department to evaluate
these activities and determine the most appropriate tool for coverage
under the Act.
We also received a comment from the Deschutes Basin Board of
Control requesting a 4(d) rule; we address their comments later, under
Comment (50).
Based on the information above, we have not proposed a rule under
section 4(d) of the Act for the Oregon spotted frog, and the general
provisions at 50 CFR 17.31 will apply. Additionally, the normal take
provisions provided by section 17.31(b) of the Act to State
conservation agencies operating a conservation program pursuant to the
terms of a cooperative agreement with the Service in accordance with
section 6(c) of the Act will apply.
We may continue to consider developing a proposed 4(d) rule after
this listing is finalized if we were to receive appropriate specific
information that would provide us with a high level of certainty that
such activities would lead to the long-term conservation of Oregon
spotted frogs.
(18) Comment: WDFW asserted that our statement indicating that
there has been little survey effort in California since 1996 is
incorrect. The commenter indicated that the USGS out of Point Reyes and
the USFS group out of Humboldt State University have done extensive
surveys in northeastern California, including a number which were
conducted after 1996, and some of which overlap the historic range of
the Oregon spotted frog.
Our response: In response to this comment, we contacted staff at
Humboldt State University and USGS at Point Reyes. We confirm that
surveys have been completed in northeastern California, but neither
group encountered Oregon spotted frogs during their survey work.
However, extensive surveys have not been conducted, and, therefore, we
cannot confirm that Oregon spotted frogs are extirpated in California.
(19) Comment: WDFW suggested that more emphasis needed to be placed
on the benefits that moderate controlled grazing can have on Oregon
spotted frog habitat, stating that grazing is most likely to be a
benefit and could be employed as an important tool across western
Washington and British Columbia, Canada, where reed canarygrass
achieves problematic densities.
Our response: While we examined both the potential positive and
negative effects of livestock grazing, we concluded that grazing is not
uniformly beneficial across the range of the Oregon spotted frog.
Please see our response to Comment (4).
(20) Comment: WDOE suggested that text in the proposed rule appears
to confuse the Sumas River in Whatcom County, Washington, with the
Chilliwack River in British Columbia, Canada. The commenter asserted
that in one part of the rule the Sumas River is described as a
tributary to the Lower Chilliwack River watershed, which the commenter
believed to be correct, but pointed out that elsewhere in the rule the
Sumas River was used interchangeably with the Chilliwack River and/or
the Lower Chilliwack River, which the commenter felt was incorrect.
Our response: The confusion arises from the multiple geographic
scales used in this rule. The section entitled ``Current Range/
Distribution'' summarized data at the 4th field sub-basin scale, except
for Washington, where Oregon spotted frogs are currently distributed in
only one 5th-field watershed within the six occupied sub-basins. The
Sumas River is a tributary to the Lower Chilliwack River watershed (5th
field) and to the Fraser River sub-basin (4th field). Because we are
considering the species across its range, we attempted to use a
consistent naming convention across the range. We have made changes to
the text of this rule to more clearly identify the Sumas River as
tributary to the Lower Chilliwack River watershed and the Fraser River
sub-basin.
(21) Comment: WDOE indicated that our statement under Factor D,
Local Laws and Regulations, regarding shoreline setbacks and impervious
surfaces in Whatcom County was incorrect.
Our response: We referred to the Whatcom County SMP, Table
23.90.13.C, which provides the setbacks for a variety of activities.
The setbacks may be as little as 5 ft; however, in the areas where
Oregon spotted frogs are known to occur in the county, the land
designations are primarily rural, resource, conservancy, or natural,
and the setbacks in these areas begin at 15 ft (Whatcom County SMP
2008, pp. 96-99). The impervious surface allowance of 10 percent is
also included in this table.
(22) Comment: WDNR stated that the proposed listing of the Oregon
spotted frog presents a potential conflict between the long-term
Washington State Forest Practices Rules and their associated HCP,
citing a misalignment between management strategies for wetlands and
riparian areas and the habitat maintenance and enhancement needs for
the Oregon spotted frog. Because the Oregon spotted frog is not a
covered species under the Forest Practices HCP and the proposed listing
decision does not draw a specific determination regarding the potential
for incidental take of the species while conducting forest management
activities covered by the Forest Practices HCP, the regulating State
agency expressed its
[[Page 51700]]
desire to avoid a circumstance where actions approved to benefit one
set of listed species may potentially adversely impact another listed
species.
Our response: Oregon spotted frog, as a species, is not generally
dependent on a forested landscape; therefore there is a lower
likelihood that Oregon spotted frogs or their habitat will be
negatively affected by forest management activities. That said, Oregon
spotted frogs may occur in areas delineated as forested wetlands (e.g.,
along Trout Lake Creek) or downstream from forest management
activities, and management agencies should be aware of the activities
that may negatively impact them. An example of such activity may
include upslope management activities that alter the hydrology of
streams, springs, or wetlands upon which Oregon spotted frogs depend.
Activities that are currently allowed under the Forest Practices HCP
may impact Oregon spotted frogs or their habitat. Conversely,
disallowing management actions that could improve habitat for Oregon
spotted frogs may be detrimental. For example, a lack of options to
manage trees and/or shrubs that encroach into the wetlands may reduce
the availability of suitable egg-laying habitat. We wish to highlight
that some management of riparian areas under the Forest Practices HCP
may or may not result in incidental take of Oregon spotted frogs,
depending on the timing. For example, incidental take would not be
anticipated for tree or shrub removal conducted during the dry season.
We also note that areas of concern are limited to a very small subset
of lands included or covered under the Forest Practices HCP. If there
is a process for landowners to obtain a variance from WDNR in order to
re-establish or enhance Oregon spotted frog habitat, the Service
recommends that WDNR make that process available to willing landowners.
Otherwise, the Service recommends WDNR consider its options for
obtaining incidental take coverage for its Forest Practice Permit
process.
Public Comments
(23) Comment: One commenter expressed concern about the
availability of unpublished reports in the development of the rule.
Our response: The Service receives and uses information on the
biology, ecology, distribution, abundance, status, and trends of
species from a wide variety of sources as part of our responsibility to
implement the Act. To assure the quality of the biological, ecological,
and other information used by the Service in our implementation of the
Act, it is the policy of the Service (59 FR 34271; July 1, 1994) to
require biologists to evaluate all scientific and other information
that will be used to support listing actions to ensure that information
used is reliable, credible, and represents the best scientific and
commercial data available. Supporting documentation we used in
preparing the proposed rule was available for public inspection on
http://www.regulations.gov, or at the U.S. Fish and Wildlife Service,
Washington Fish and Wildlife Office (see FOR FURTHER INFORMATION
CONTACT). Instructions for how to gain access to this information was
provided in the August 29, 2013, proposed rule.
(24) Comment: Three commenters expressed concerns that the listing
of the Oregon spotted frog would result in changes to mosquito
abatement, specifically along the Deschutes River. Two of the
commenters believe that managing local water resources to increase the
wetlands for the Oregon spotted frog would result in greater numbers of
mosquitos and would create a potential public health risk attributable
to mosquito-borne encephalitic disease (West Nile virus). Conversely,
the third commenter suggested that an extinction of the Oregon spotted
frog would increase the potential for insect overpopulation, causing
further disruption to the ecosystem and effectively endangering other
vulnerable species.
Our response: Mosquito control continues to occur in the Deschutes
River area, specifically through application of the biological control
agent Bti. Studies indicate Bti typically does not significantly affect
vertebrates (Siegel et al. 1987, p. 723; Merritt et al. 1989; pp. 408-
410; Hanowski et al. 1997, entire; Niemi et al. 1999, entire; Siegel
2001, entire), including amphibians (multiple studies synthesized in
Glare and O'Callaghan 1998, pp. 24, 28). However, indirect effects may
occur through reduction of food (insects) (Hanowski et al. 1997; Niemi
et al. 1999, entire; Mercer et al. 2005, p. 692). The Service considers
these potential indirect effects on the Oregon spotted frog to be
negligible, considering the breadth of the Oregon spotted frog's diet
and the specificity of the mosquito abatement treatments employed,
which primarily affects the larvae of nematoceran (``thread-horned'')
flies (the group that includes mosquitos). At this time, we do not
anticipate changes to the mosquito control program using Bti. Should
more or newer information relating specifically to direct or indirect
impacts on Oregon spotted frogs become available in the future, the
Service will revisit this issue. We have updated the Background section
of this rule to include a short discussion of the indirect effects of
Bti and methoprene on the Oregon spotted frog.
(25) Comment: Two commenters specifically requested close
collaboration between the Service and the USFS to ensure timely
conservation of the Oregon spotted frog on USFS lands through the
revision of already existing projects, and development of standards,
guidelines, or management plans.
Our response: The Service coordinates and provides technical
assistance to other Federal agencies, including the USFS, on a broad
scope of work. The USFS has been proactive in developing site
management plans specific to Oregon spotted frogs. Development of
forest plans, land use classifications, standards and guidelines, and
project planning remains under the purview of the Federal agencies
developing such products. If a Federally authorized, funded, or
conducted action could affect a listed species or its critical habitat,
the responsible Federal agency is then required to enter into
consultation with the Service under section 7 of the Act.
(26) Comment: A representative of Modoc County, California,
asserted that the Service failed to follow Federal procedures when
publishing the proposal to list the Oregon spotted frog. The commenter
cited case law determining that the Service is required to give actual
notice to local government of its intent to propose a species for
listing.
Our response: Under 16 U.S.C. 1533(b)(5)(A)(ii), the Secretary is
required to provide actual notice of the proposed regulation to each
county in which the species is believed to occur. The Oregon spotted
frog is not currently known or believed to occur in either Modoc or
Siskiyou Counties; therefore, the Service did not provide notification
to these counties.
(27) Comment: One commenter suggested that more attention be given
to the extent of the historical range of the Oregon spotted frog and
requested an evaluation of the factors likely contributing to the
demise of historical populations as a way to become informed about the
factors affecting the remaining populations.
Our response: Historical location information is presented in this
rule to give the reader perspective on the decline of the species, but
a listing analysis is focused on the current distribution and the
threats to those populations. In many of the historically
[[Page 51701]]
occupied watersheds, the specific location information necessary to
determine why Oregon spotted frogs may no longer occur there is
unavailable, but can reliably be attributed to human development. The
effects of towns, homes, or infrastructure for both human habitation
and for agriculture have resulted in the loss of suitable habitat in
many of the historically occupied watersheds (for example, the Green
River/Lake Washington area in Washington). While we agree that
evaluating reasons for loss in historically occupied areas may inform
ways to recover the species, the purpose of this evaluation is to
determine the threats facing the currently occupied areas.
(28) Comment: Two commenters suggested that unidentified occupied
locations may exist for Oregon spotted frog--one because a handful of
such sites were documented as recently as 2011 and 2012, the other
because of a 1991 document suggesting that additional surveys be
conducted on the east side of the Cascade mountain range. In addition,
one of the commenters asserted that the Service does not have any
credible data regarding Oregon spotted frog populations on private
lands adjoining the Conboy Lake NWR.
Our response: The information provided by the Service in the
Current Range/Distribution section includes the newly identified
watersheds and the one reintroduction project. All of these locations
are within the historical range (i.e., Puget Trough) of the Oregon
spotted frog. While we continue to survey for Oregon spotted frogs in
potentially suitable habitat, both in historically and non-historically
occupied sub-basins, we cannot speculate as to whether additional
populations may occur. In addition, our analysis for listing purposes
is based on the status and threats according to the best scientific and
commercial data available, including occurrence records.
Subsequent to the 1991 document cited by the commenter, the Oregon
spotted frog and Columbia spotted frog were separated into two species
(see Taxonomy section). In Washington, frogs in the higher elevations
near the Cascade crest (both east and west) have been identified as
Cascades frogs and in the lower elevations on the east side of the
Cascade Crest as Columbia spotted frogs.
While specific survey information does not exist for the private
lands adjoining Conboy Lake NWR, the habitat for the Oregon spotted
frog does not stop at the boundaries of the refuge. Due to the
contiguous nature of the known occupied habitat on the refuge with the
habitat on the adjoining private lands, the Service considers the
adjoining lands occupied.
(29) Comment: One commenter believed we were inconsistent in our
application of the status of the Oregon spotted frog occupied sub-
basins. We denoted the Lower Fraser River and Middle Klickitat sub-
basins as declining and White Salmon River sub-basin as having no
determinable trend because numbers may be rebounding in portions of the
Trout Lake area. The commenter believes we should not have concluded
that the Middle Klickitat sub-basin was declining because of a
similarity to the White Salmon River sub-basin.
Our response: One of the challenges in developing a listing
determination for a species that spans multiple States is that
scientific and monitoring data are often collected according to the
methods preferred by individual researchers, rather than under a
standard protocol. Results from some data collection methods can be
compared to results from other methods through bridging studies, but
some results are not comparable. Where we have no supported way to make
comparisons between the results from differing data collection methods,
we may not be able to draw conclusions, even if the data look similar.
Based on the best data available, evidence indicates there is a
declining trend in the Middle Klickitat River sub-basin (Hayes and
Hicks 2011, entire; Hallock 2013, p. 36). There is no equivalent
evidence available for the Trout Lake area (Hallock 2012) that
indicates there are areas within the Middle Klickitat River sub-basin
that are rebounding.
(30) Comment: One commenter asserted that the Service estimate for
the number of Oregon spotted frogs in Upper Deschutes River and Little
Deschutes River sub-basins (3,530 and 6,628 breeding adults,
respectively) indicates that each population is of considerable size
and viability and highlighted the co-existence of these populations in
areas where human activity, such as irrigation water storage, release,
diversion, and return, has been prevalent for more than a century.
Our response: The Service does not consider the minimum population
estimates in the Upper Deschutes River or Little Deschutes River sub-
basins to constitute a population of ``considerable size and
viability.'' Franklin (1980) proposed the 50/500 rule, whereby an
effective population size (Ne) of 50 is required to prevent
unacceptable rates of inbreeding and an Ne of 500 is
required to ensure overall genetic variability. Phillipsen et al.
(2010) compared the adult Oregon spotted frog census population (N =
428) from a breeding site near Sunriver, Oregon, to the effective
population size (Ne = 36.7) with the result of
Ne/N = 0.086, which fell within the general range of DNA-
based estimates for ranid frogs (Phillipsen et al. 2010, p. 742).
Application of the 50/500 rule provides that an Oregon spotted frog
population of greater than 581 breeding adults (N/Ne =
50/.086) at the Sunriver breeding site would be required to prevent
inbreeding depression and a population of 5,814 breeding adults (N/
Ne = 500/.086) would be required for a high probability of
survival over time. Thus, the minimum population estimate for the Upper
Deschutes River sub-basin (3,530) is considerably less than the
population needed for only one site, Sunriver (5,814). Therefore, the
Service does not consider the current Upper Deschutes River sub-basin's
Oregon spotted frog populations to be of adequate size or viability.
Within the Little Deschutes River sub-basin, most of these breeding
adults are confined to one area, Big Marsh (5,324 out of 6,628), which
is not subject to irrigation district activities. We stated that the
trend at Big Marsh appears to be increasing; however, there are no
trend data available for the remainder of the sub-basin. Therefore, our
determination of an undetermined trend for this sub-basin is accurate.
We agree that the Oregon spotted frogs in the Upper Deschutes River
and the Little Deschutes River sub-basins continue to be present within
areas of regulated flow associated with irrigation district activities
for more than a century. However, without the irrigation district
activities, the Oregon spotted frog populations in these sub-basins may
be higher in number and better distributed throughout the sub-basin.
(31) Comment: One commenter believes the Service lacks sufficient
evidence to establish that the Oregon spotted frog should be listed as
a threatened species. The commenter stated that while the Service
asserts that data show the frog is disappearing from its historical
range, the Service admits that it has not studied population trend data
in 13 of 15 sub-basins where the frog is known to occur. Therefore, the
commenter claims that the Service has based its proposed listing
decision not on substantial evidence of frog decline, but on absence of
evidence countering a presumption of decline.
Our response: The Service is not required to show that a species is
in decline in order to make a determination that it is threatened. A
listing determination is an assessment of the best scientific and
commercial
[[Page 51702]]
information available regarding the past, present, and future threats
to the Oregon spotted frog. While the loss of Oregon spotted frog
across the historical distribution and the status of the species within
its current range is considered in this assessment, the majority of the
assessment is focused on the ongoing and future threats to the species
within the currently occupied areas. All of the known Oregon spotted
frog occupied sub-basins are currently affected by one or more threats.
The immediacy, severity, and scope of these threats are such that the
Oregon spotted frog is likely to become endangered throughout all or a
significant portion of its range within the foreseeable future.
(32) Comment: One commenter suggested that the proposed listing
rule should reassess the role shrubs play in support of beaver re-
establishment in each frog sub-basin, since beaver re-establishment
will affect both tree encroachment and succession to a tree-dominated
community. The commenter noted that if a proper hydrologic regime were
restored and maintained, plant communities that provide frog habitat
would not succeed to tree-dominated communities.
Our response: We acknowledge that shrubs are an important component
for maintaining beaver habitat, but highlight the threat posed by
succession to a tree- and/or shrub-dominated community where natural
disturbances processes (such as beavers, flooding, and fire) have been
or continue to be removed. We are especially concerned about wetland
and riparian areas that provide egg-laying habitat that is being
actively planted with willows and other riparian shrubs in order to
cool water temperatures for salmonids. These actions can degrade or
eliminate the shallow open-water conditions necessary for egg laying.
We do not advocate for shrub removal throughout areas inhabited by
Oregon spotted frogs, especially where they support beavers, but where
natural disturbance processes are lacking, succession to shrub- and
then tree-dominated communities will continue to pose a threat.
(33) Comment: Two commenters stated that the use of the term
``early seral vegetation'' to represent egg-laying habitat was not
supported and does not conform to seral stages of plant communities of
riparian areas and wetlands at cited in Kovalchik (1987) and Crowe et
al. (2004). In addition, the commenters suggested that too much
disturbance can force wetland communities toward drier plant
associations, which may not favor Oregon spotted frogs.
Our response: Our use of the term ``early seral'' in the proposed
listing rule was intended to convey the idea of non-forested areas in
early stages of succession. Use of the term ``late seral'' to represent
a wetland that is in a ``stable state'' where change in the vegetation
is minimal over time is indeed accurate when applied to an intact
wetland ecosystem, but may be confusing to those who may equate the
term ``late seral'' to ``older forest.'' We note that Oregon spotted
frogs do not currently occur in intact stable wetland ecosystems
throughout the majority of their range; they occur in systems that have
been modified by humans such that the normal disturbance processes have
been lost and succession to trees and shrubs is occurring. We agree
that classification of the Oregon spotted frog as an early seral-
dependent species is not entirely accurate, but note here that the
vegetation at egg-laying areas in at least 7 of the 15 occupied sub-
basins currently consists of reed canarygrass, not native wetland
species. Maintenance of the appropriate vegetation height and water
depth necessary for egg laying within these areas is crucial to the
persistence of Oregon spotted frogs in these sub-basins. In this rule,
we have revised the language in the Background and Summary of Factors
Affecting the Species sections, where appropriate, to remove the term
``early seral.'' We highlight that vegetation succession or
encroachment into breeding sites for Oregon spotted frog constitute a
threat to the species.
(34) Comment: One commenter asserted that the threat from grazing
was understated in the proposed rule and suggested a more detailed
discussion of the impacts grazing has on frog habitats is needed.
Our response: The best information available on grazing in areas
occupied by Oregon spotted frog indicates there are both negative and
positive impacts. We believe we evaluated the best available scientific
information and provided a balanced summary of both the negative and
positive impacts under the ``Livestock Grazing'' section of the Factor
A discussion and that the full extent of the negative impacts have been
evaluated. For further information, please see our response to Comment
(4).
(35) Comment: Two commenters wrote regarding water management and
drastic draw-downs below the Wickiup Reservoir in the Upper Deschutes
sub-basin that have resulted in fish kills. These commenters indicated
the Oregon Water Resources Department dewaters the Upper Deschutes
River annually in the fall and expressed concern at the lack of Service
involvement to protect animals under our jurisdiction.
Our response: The Service does not have direct regulatory authority
over the water management within the Deschutes River Basin. By law, all
surface and ground water in Oregon belongs to the public, and the
Oregon Water Resources Department is the public State-level agency
charged with administration of the laws governing surface and ground
water resources, including the protection of existing water rights.
Much of the river water within the Deschutes River was allocated long
ago and, as such, is subject to the laws governing water rights. If a
Federally authorized, funded, or conducted action may affect a listed
species or its critical habitat, the responsible Federal agency must
enter into consultation with the Service under section 7 of the Act.
However, where there is no Federal nexus, State laws govern water
management. With this final rule, however, the Act's prohibitions will
apply to all activities that harm Oregon spotted frogs, and we expect
to work with landowners to develop habitat conservation plans that
address those activities.
(36) Comment: One commenter stated that the proposed rule suggests
nonnative predators are transferred via the pumping of groundwater.
Another commenter believed the proposed rule did not adequately weight
the importance of groundwater resources to the persistence of Oregon
spotted frog and felt the proposed rule should have included an
assessment of the threats to groundwater, due to the contributions it
makes to the maintenance of Oregon spotted frog habitat.
Our response: There is no biological information that suggests
nonnative predators are transferred via groundwater pumping, and the
proposed rule did not state or intend to imply there was such a threat.
The final rule remains consistent with this original position.
The Service agrees that there is need to protect groundwater
resources, as many wetland habitats occupied by Oregon spotted frogs
are supported by groundwater. Pumping of groundwater can result in
lower water levels in groundwater systems, diminished flow of springs,
and reduced streamflow (Gannett et al. 2007, pp. 59-60, 65), but the
extent of groundwater pumping effects to streamflow within Oregon
spotted frog sub-basins and its impact on Oregon spotted frogs is
currently unclear (Gannett et al. 2007, p. 65). In the Upper and Little
Deschutes River sub-basins, the analysis of groundwater changes
discussed in Gannett et al.
[[Page 51703]]
(2013) is difficult to correlate directly with impacts to Oregon
spotted frog. There is a scarcity of hydrologic gauges in certain parts
of the occupied sub-basins, and there are only five well-testing
locations upstream of Bend, Oregon, in proximity to areas occupied by
Oregon spotted frog. Although the Little Deschutes River sub-basin
experienced groundwater level declines since 2000, Gannett et al.
(2013) stated that wells in the ``La Pine sub-basin south of Bend''
tend to respond to climate cycles, and show no evidence of discernible
pumping-related trends due to the distance from large pumping centers.
Similarly, the primary increase in groundwater pumping in the upper
Klamath Basin has not occurred within Oregon spotted frog occupied sub-
basins. The Service has little conclusive information at this time
regarding groundwater pumping as a threat to Oregon spotted frogs.
(37) Comment: One commenter asserted that water management
activities in the Glenwood Valley (the Middle Klickitat River sub-
basin) may be artificially enhancing Oregon spotted frog habitat in
that area because the landowners flood a significant portion of the
valley to provide frost protection to the reed canarygrass they use for
summer livestock forage and/or commercially produce. The commenter
suggested that if water were allowed to runoff naturally, the area of
available Oregon spotted frog habitat would be much smaller and would
dry up sooner.
Our response: As explained in the Background and Summary of Factors
Affecting the Species sections, water management in the Glenwood Valley
is a complicated issue involving multiple landowners, including both
public and private. Retention of water in locations that attract egg-
laying behavior may create an ``ecological trap'' by trapping larvae
and/or juvenile frogs if water is not retained until they are matured
enough to move or if those locations are not hydrologically connected
to permanent water via surface water along a gradual slope. These
artificially flooded egg-laying areas may be creating population
``sinks'' and facilitating the decline of the population by diverting
gravid females from higher quality, natural egg-laying locations. In
addition, the current water management drains areas that in a natural
setting might hold water throughout the year; whereas, currently, the
surviving frogs are restricted to the ditch system, along with their
predators, for a majority of the summer and winter. In the absence of
additional compelling information, the Service continues to assert that
water management is a threat to Oregon spotted frogs in the Middle
Klickitat River sub-basin.
(38) Comment: One commenter asked that the Service clarify whether
stormwater detention or retention facilities provide Oregon spotted
frog habitat, including whether these facilities are beneficial or
detrimental to the frog. (Oregon spotted frogs have been found within
private storm drainage wetponds within Bend, Oregon.) The commenter
further asked whether the State should continue to recommend that
stormwater be directed away from frog habitat (as advised in Nordstrom
and Miller 1997) if Oregon spotted frogs are shown to benefit from
stormwater retention facilities.
Our response: The only known occurrence of Oregon spotted frogs
using a stormwater retention pond occurs at the Old Mill within the
City of Bend, Oregon. Year-round water is purposefully held within this
particular pond because it serves as a ``casting pond'' for learning to
fly fish. The Service does not have information to indicate that
seasonally wet stormwater ponds are either a benefit or detriment to
Oregon spotted frog populations that utilize the Deschutes River within
the City of Bend.
In Washington State, Nordstrom and Milner (1997) remains the
current accepted management practices guide. It clearly states,
``stormwater runoff from urban developments should not be diverted into
spotted frog habitats. Urban runoff often contains heavy metals and
other pollutants that may affect frogs.'' Therefore, the information
regarding controlling stormwater runoff away from frog habitat and the
Washington Priority Habitat and Species Management Recommendations is
accurate as presented.
Brand and Snodgrass (2010) concluded anthropogenic wetlands may be
important to amphibian conservation in suburban and urban areas, but
cautioned about the contaminants in the stormwater ponds. In addition,
inferences from this study should be made very judiciously because the
amphibian species studied were primarily terrestrial and only used the
structures during the breeding season and their ``natural'' locations
dried up before metamorphosis, so the structures were not providing for
the essential needs of the associated amphibians and were essentially
acting as a breeding sink.
The Service would not recommend that these types of facilities be
constructed in or near Oregon spotted frog habitat because of the
potential for creating ponds that do not remain wetted and could trap
frogs or larvae, retain deeper water that attracts bullfrogs, or expose
Oregon spotted frogs to contaminants.
(39) Comment: One commenter believed that the Service's discussion
of development under Factor A was not well supported and argued that
wetlands receive enough protections from Federal, State, and county
regulations to be immune from the impacts of development.
Our response: The link between the frog's status and loss of
wetlands is documented under both Factor A and Factor D. Ongoing loss
of wetlands is predominantly attributable to development, including
urban (housing and infrastructure) and agricultural. While some
setbacks are required under existing regulations, not all ``wetlands''
are regulated in an equivalent manner, and not all counties or States
have equivalent regulations. Additionally, not all Oregon spotted frog
habitat is classified as ``wetland'' under county or State regulations,
and thus the loss of these habitats are not accounted for under
estimates of wetland loss. As discussed in our analysis under Factor D,
we determined that the existing regulatory mechanisms are not
sufficient to reduce or remove threats to Oregon spotted frog habitat,
particularly habitat loss and degradation.
(40) Comment: One commenter believed the summary of the disease and
predation section appeared to contradict the first paragraph of the
section, pointing out that the first paragraph cites documentation that
nonnative predaceous species are found in 20 of 24 sites while the
summary states that at least one nonnative predaceous species occurs
within each of the sub-basins currently occupied by Oregon spotted
frogs.
Our response: These findings are discussed at different scales.
Hayes et al. (1997, p. 5) documented at least one introduced predator
in 20 of 24 individual sites surveyed from 1993-1997 in British
Columbia, Washington, and Oregon. However, our summary is focused on
the presence of nonnative predators at the sub-basin scale, not in
individual sites; in other words, each occupied sub-basin has one or
more sites with nonnative predators present. Further information on
specific sites and sub-basins that are known to have predaceous
nonnative species (made available within our Threats Synthesis
Rangewide Analysis) is available online at both http://www.regulations.gov and the Washington Fish and Wildlife Service
Office's Web site http://www.fws.gov/wafwo/osf.html.
(41) Comment: One commenter asserted that increases in the
population
[[Page 51704]]
of sandhill cranes in the Middle Klickitat River area and reports from
local residents that indicate river otters have also moved back into
the area may also be affecting the size of the Oregon spotted frog
population.
Our response: We have no evidence to support or disprove that
increasing populations of native species may negatively impact Oregon
spotted frog populations in the Middle Klickitat River area. Cranes and
otters may be playing a beneficial role for Oregon spotted frogs by
preying on bullfrogs. We continue to recommend actions that address the
impacts from introduced (nonnative) species, rather than native
species.
(42) Comment: One commenter felt that the information provided
under Factor C regarding Bd is inconsistent with Hayes et al. (2009),
which posited that Bd was a contributor to the observed declines at
Conboy Lake NWR and Trout Lake NAP. The commenter goes on to note that
the referenced article also posited that the observed declines coupled
with the unknown susceptibility of Oregon spotted frogs to Bd should be
a cause for concern and then stated that this concern is heightened by
the fact the Conboy Lake NWR is the only place where Oregon spotted
frogs and American bullfrogs have successfully co-existed for over 60
years. The commenter's concern stems from data demonstrating that
bullfrogs are known to carry Bd asymptomatically (citing Daszak et al.
2004; Garner et al. 2006); therefore the potential for Bd transmission
within and among species at Conboy Lake NWR could be high.
Our response: We agree that Bd may be a cause for concern; however,
there is no direct evidence that the declines in Conboy Lake area are
attributable to Bd, and recent studies conducted by Padgett-Flohr and
Hayes (2011) indicate that Oregon spotted frogs are less susceptible to
Bd than many other frog species. The lack of co-occurrence with
bullfrogs at Trout Lake NAP could potentially explain why that
population is able to rebound, while Conboy Lake area does not, but it
does not explain the increasing trend in the Sunriver population which
has coexisted with bullfrogs for more than 40 years. There are a number
of other contributing factors in the Trout Lake NAP that may explain
the increasing population, such as significant improvement of the
habitat conditions. Additional studies are necessary to determine
whether Bd is a threat rangewide.
(43) Comment: One commenter requested clarification of which
specific Urban Growth Area includes Fish Pond Creek because designation
as an Urban Growth Area specifies the allowable permitted density of
developments.
Our response: Fish Pond Creek is a tributary that flows directly
into Black Lake from the east. The area where the frogs have been found
breeding is within the Tumwater Urban Growth Area. Text has been added
to the Factor D discussion in this rule to clarify this Urban Growth
Area.
(44) Comment: Two commenters highlighted that shoreline, riparian,
and wetland property owners throughout the PNW are regularly required
through Federal, State, and local programs to improve fish habitat as
mitigation for development and emphasized the involuntary nature of
some of these mitigation programs. The commenters pointed out the
apparent contradiction where the Service's proposed listing rule
identifies such mitigation programs as having already contributed to
the Oregon spotted frog's decline. The commenters stated his or her
concern that a ``dueling species'' scenario between fish and frogs will
not be resolved by listing the Oregon spotted frog as a threatened
species, but will mean that property owners will face competing
requirements stemming from the Act and other programs, and will be
subject to potential liability on multiple fronts, either for refusing
to engage in fish habitat mitigation (to avoid harming frogs), or for
engaging in fish habitat mitigation activities that harm frogs. The
commenters felt that a property owner's only alternative in such a
situation may be to forgo using his or her property altogether and
implied that the Service may be liable for a regulatory taking if
property use restrictions resulting from enforcement of the Act deprive
an owner of economic use.
Our response: We agree that habitat objectives for fish, and salmon
species in particular, may in some cases contradict those for Oregon
spotted frogs. In many cases, laws and regulations that pertain to
retention and restoration of wetland and riverine areas are designed to
be beneficial to fish species, resulting in the unintentional
elimination or degradation of Oregon spotted frog habitat. In the
``Summary of Existing Regulatory Mechanisms'' under the Factor D
discussion, we state that additional regulatory flexibility would be
desirable for actively maintaining the areas essential for the
conservation of the Oregon spotted frog. For example, grazing is an
active management technique used to control invasive reed canarygrass,
but CAOs in some Washington counties prohibit grazing within the
riparian corridor. We also highlight the fact that the areas where
these incompatibilities apply are limited in scope to four Oregon
spotted frog-occupied sub-basins in Washington, a very small amount of
area relative to the range of salmonids.
The Act does not allow the Service to refrain from listing a
species in an instance such as this, where one species' habitat needs
are different or incompatible with those of another listed species. In
theory, two species that co-existed in the past should be able to co-
exist in the present and future; however, due to human alteration of
the naturally functioning ecosystem, human management of the ecosystem
upon which these species depend now needs to accommodate the habitat
needs of both species. As such, the incompatibilities and means to
balance recovery objectives will be addressed in any future recovery
plan for the Oregon spotted frog and are not relevant to a listing
decision.
As for the commenters' assertion that limitations on the use of
private property might effect a regulatory taking, the Act does not
allow such considerations to influence a listing decision. In any
event, the provisions of section 10 of the Act, allowing landowners to
take listed species in accordance with an approved habitat conservation
plan, are generally an effective means of resolving such issues without
foreclosing all use of property.
(45) Comment: One commenter felt that our Factor D discussion
places too much emphasis on the failures of existing regulatory
mechanisms. The regulatory mechanisms are not as problematic as
depicted in the text, and the whole section should be revised to better
depict the protection provided by existing regulatory mechanisms.
Our response: As discussed in the introductory paragraph to the
Factor D analysis, we examine whether the existing regulatory
mechanisms are inadequate to address the threats to the species. We
interpret this to include relevant laws, regulations, or mechanisms
that may minimize any of the threats we described in the threat
analyses under the other four factors, or otherwise enhance
conservation of the species. This section only includes those laws,
regulations, or mechanisms that we have found to be inadequate. It does
not contain those laws, regulations, or mechanisms that we have found
to be adequate or which do not address the specific threats to the
species.
(46) Comment: One commenter stated that there is no evidence that
water quality in the habitats occupied by Oregon spotted frogs is
contaminated and asserts that because there is no evidence that water
quality is affecting
[[Page 51705]]
the populations in the Conboy Lake area or the Trout Lake NAP, the
conclusion that water quality and contamination is a threat to the
Oregon spotted frog across its range is not supported.
Our response: We have revised our conclusion about the extent of
threats due to water quality. Reduced water quality is documented in a
number of occupied sub-basins, and where this overlap occurs we
consider poor water quality and contaminants to be threats to the
Oregon spotted frog. Various parameters of water quality were
identified as issues from British Columbia south to the Klamath Basin
(see Factor E discussion). Specifically, the WDOE listed a Trout Lake
Creek segment within known Oregon spotted frog areas as not meeting
standards for fecal coliform, pH, dissolved oxygen, and temperature. We
recognize that not all water quality parameters are equal and the
standards set for fish may or may not be detrimental to Oregon spotted
frogs. However, many of the parameters that we identified in
association with water quality, such as pH and dissolved oxygen, are
applicable, as is temperature when it is resulting in algal blooms and
low oxygen levels (see discussion under the Life History section).
(47) Comment: One commenter felt that there was a conflict between
the threat analysis conducted under Factor C and the cumulative threat
analysis. The commenter requested clarification as to how the Service
could cite Blaustein et al. (1999), which the commenter interpreted as
concluding that Oregon spotted frogs were not affected by UV-B
radiation exposure or contaminants, and then determine that UV-B
radiation exposure and contaminants could negatively impact Oregon
spotted frogs in the cumulative threats analysis.
Our response: Our threat analysis under Factor C did not say that
Oregon spotted frogs are not affected by UV-B radiation, only that at
present, the extent of population-level impacts from UV-B exposure is
unknown. We highlight here that the Blaustein et al. 1999 study was
conducted on eggs, but more recent work indicates that larvae
(tadpoles) are more susceptible than embryos (Bancroft et al. 2008) and
that UV-B radiation interacts synergistically with other environmental
stressors. We also considered climate change as potentially playing a
role in increased exposure to UV-B radiation if water depth at egg-
laying and rearing locations is reduced. Our threat analysis also did
not state that contaminants do not affect Oregon spotted frogs.
Although we acknowledged that more ecotoxicology is warranted, the
analyses provided a variety of impacts that contaminants can have on
the species. Like UV-B radiation exposure, contaminants interact
synergistically with other environmental stressors. Therefore, it is
appropriate to include UV-B radiation exposure and contaminants in the
cumulative effects analysis because of the complex interactions of
stressors and the response Oregon spotted frogs may exhibit to varied
combinations of these stressors.
(48) Comment: One commenter stated that the Service failed to
sufficiently analyze whether the populations of Oregon spotted frogs
constitute one or more distinct population segments (DPSs),
particularly in the Upper Deschutes and Little Deschutes sub-basins.
The commenter asserted that the Service would have a strong basis to
find that these populations constitute one or more DPS given the
sizable populations in these sub-basins, and, as such, it is premature
to list these populations as threatened.
Our response: Congress has instructed the Secretary to exercise
authority with regard to DPSs ``* * * sparingly and only when the
biological evidence indicates that such action is warranted'' (Senate
Report 151, 96th Congress, 1st Session). We evaluated whether any
populations of the Oregon spotted frog constituted a DPS prior to our
proposed listing rule; however, after conducting our threats analysis
we concluded that the Oregon spotted frog is a threatened species
across its range. Therefore, because we have determined that the Oregon
spotted frog is threatened rangewide, there is no regulatory benefit in
designating separate DPSs.
(49) Comment: One commenter noted that impacts from recreational
access are not documented in the proposed listing until the section
where the list of examples of activities conducted, regulated, or
funded by Federal agencies is addressed. The commenter questioned
whether or not recreational impacts constitute a real problem. The
commenter further questioned whether or not river restoration should be
included in this section, as Oregon spotted frogs are not a
``riverine'' species.
Our response: This list of examples of activities was provided to
draw the Federal agency's attention to the types of activities that may
require conference or consultation under section 7(a) of the Act;
however, we are not aware that they are occurring or planned at this
time. If they were to occur, recreation management actions, such as
development of campgrounds or boat launches adjacent to or in Oregon
spotted frog habitat, may result in impacts to the species or its
habitat or both. Additionally, river restoration activities also may
result in impacts to the species or its habitat or both because Oregon
spotted frogs are closely tied to creeks and rivers, such as the Samish
and Black Rivers in Washington and the Deschutes River in Oregon.
(50) Comment: The Deschutes Basin Board of Control (DBBC) requested
a rule under section 4(d) of the Act that would not prohibit incidental
take of Oregon spotted frogs during routine irrigation district
activities, such as the storage, release, diversion, and return of
water, if those activities are conducted in accordance with State law;
and within ranges of storage, release, diversion, and return
experienced since 1980, or within limits established in a HCP approved
by the Service in accordance with section 10(a)(1)(B) of the Act. The
DBBC also requested the 4(d) rule address the maintenance, operation,
repair, or modification of existing district facilities if, among other
requirements, these activities do not result in the direct physical
modification of habitat occupied by the Oregon spotted frog or if these
activities are addressed in an HCP. The DBBC requested that we provide
another opportunity for public comment on our 4(d) rule determination
before issuing a final rule.
Our response: We appreciate the DBBC's desire to consider
conservation of Oregon spotted frogs in carrying out their ongoing
activities. In our proposed listing rule, we indicated we are
considering whether it is necessary and advisable to develop a 4(d)
rule that would not prohibit take that is incidental to implementing a
State comprehensive Oregon spotted frog conservation program, regional
or local Oregon spotted frog conservation programs, and activities or
efforts conducted by individual landowners that are outside of a more
structured program but are still consistent with maintaining or
advancing the conservation of Oregon spotted frog. Further, we
indicated that we would consider specific information that would
provide us a high level of certainty that a conservation program would
lead to the long-term conservation of Oregon spotted frogs (see
Consideration of a 4(d) Special Rule in the August 29, 2013, proposed
listing rule).
Given the storage, release, and diversion of water in the Upper
Deschutes River and the Little Deschutes River were identified in our
proposed listing rule as sources of Oregon spotted frog habitat loss or
[[Page 51706]]
modification, the information provided by DBBC did not provide the
information we needed to evaluate the program's potential conservation
benefits to the Oregon spotted frog. However, we have been working with
the DBBC, and funding has been provided, to develop a HCP. If the HCP
is finalized and permitted by the Service, it will likely authorize
incidental take of Oregon spotted frog resulting from routine
irrigation district activities, such as those described in their
comment letter, while conserving the Oregon spotted frog consistent
with the permitting requirements of section 10 of the Act. Such a
permit would negate the need for coverage under a 4(d) rule. We
encourage the DBBC to continue working with us to develop and finalize
the HCP in order to authorize incidental take associated with these
activities. Although we are not reopening a public comment period on
the proposed listing, as requested by the DBBC, we may continue to
consider developing a proposed 4(d) rule after this listing is
finalized if we were to receive appropriate specific information that
would provide us with a high level of certainty that such activities
would lead to the long-term conservation of Oregon spotted frogs.
Summary of Changes From the Proposed Rule
We fully considered comments from the peer reviewers and from the
public on the proposed rule to develop this final listing for Oregon
spotted frog. This final rule incorporates changes to our proposed
listing based on the comments that we received that are discussed
above. We expanded our discussion of water quality to acknowledge
maximum levels as being toxic to amphibians and provided maximum limits
set by the EPA for human drinking water. We also expanded our water
quality discussion to include information on the effects of low
dissolved oxygen and revised our conclusion concerning the extent of
threats due to water quality. We added text to the ``Hydrological
Changes'' section in the Factor A discussion of this rule to reflect
the potential of manmade barriers to hinder frog movement. We added
language discussing the effects that soil compaction may have on water
holding capacity and revised language in the Background and Summary of
Factors Affecting the Species sections, where appropriate, to remove
the term ``early seral.'' We have updated the sub-basin information to
include 2013 data where the new information expanded the distribution
or significantly changed the minimum population estimate. Based on
feedback from one of our peer reviewers, language regarding the number
and distribution of the known Oregon spotted frogs in the Upper
Deschutes River sub-basin has been revised. We have updated the
Background section to include a short discussion of the indirect
effects of Bti and methoprene on Oregon spotted frogs, and we added
some text elsewhere to further explain our conclusion about parasite-
induced malformations. We revised our discussion of reproduction to
include additional uncertainty regarding the number of clutches of eggs
a female may produce per year. We also added text to the Factor D
discussion to clarify the boundaries of the Urban Growth Areas. In
addition, we corrected several citations and made editorial corrections
in response to comments.
Determination
Section 4 of the Act (16 U.S.C. 1533), and its implementing
regulations at 50 CFR part 424, set forth the procedures for adding
species to the Federal Lists of Endangered and Threatened Wildlife and
Plants. Under section 4(a)(1) of the Act, we may list a species based
on (A) The present or threatened destruction, modification, or
curtailment of its habitat or range; (B) overutilization for
commercial, recreational, scientific, or educational purposes; (C)
disease or predation; (D) the inadequacy of existing regulatory
mechanisms; or (E) other natural or manmade factors affecting its
continued existence. Listing actions may be warranted based on any of
the above threat factors, singly or in combination.
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to the Oregon spotted frog. Past human actions have destroyed,
modified, and curtailed the range and habitat available for the Oregon
spotted frog, which is now absent from 76 to 90 percent of its former
range. The Oregon spotted frog populations within two of the sub-basins
are declining, but the population trend in the other 13 sub-basins is
undetermined. However, the Oregon spotted frog is extant in only 15 of
31 sub-basins where it historically occurred. In addition, the majority
of remaining populations are isolated both between and within sub-
basins, with minimal opportunity for natural recolonization. These
isolated populations are, therefore, vulnerable to ongoing threats and
extirpation, and threats are known to be ongoing or increasing across
the range of the Oregon spotted frog, as summarized below.
Habitat necessary to support all life stages is continuing to be
impacted and/or destroyed by human activities that result in the loss
of wetlands to land conversions; hydrologic changes resulting from
operation of existing water diversions/manipulation structures, new and
existing residential and road developments, drought, and removal of
beavers; changes in water temperature and vegetation structure
resulting from reed canarygrass invasions, plant succession, and
restoration plantings; and increased sedimentation, increased water
temperatures, reduced water quality, and vegetation changes resulting
from the timing, intensity, and location of livestock grazing. Oregon
spotted frogs in all currently occupied sub-basins in British Columbia,
Washington, and Oregon are subject to one or more of these threats to
their habitat. Eleven of the 15 sub-basins are currently experiencing a
high to very high level of habitat impacts, and these impacts are
expected to continue into the foreseeable future.
Disease continues to be a concern, but our evaluation of the best
scientific information available indicates that disease is not
currently a threat to Oregon spotted frogs. At least one nonnative
predaceous species occurs within each of the sub-basins currently
occupied by Oregon spotted frogs. Introduced fish have been documented
within each sub-basin; these introduced species prey on tadpoles,
negatively affect overwintering habitat, and can significantly threaten
Oregon spotted frog populations, especially during droughts. Bullfrogs
(and likely green frogs) prey on juvenile and adult Oregon spotted
frogs, and bullfrog tadpoles can outcompete or displace Oregon spotted
frog tadpoles. In short, nonnative bullfrogs effectively reduce the
abundance of all Oregon spotted frog life stages and pose an added
threat to a species that has significant negative impacts rangewide
from habitat degradation. Nine of the 15 occupied sub-basins are
currently experiencing moderate to very high impacts due to predation
by introduced species, and these impacts are expected to continue into
the foreseeable future.
Lack of essential habitat protection under Federal, State,
Provincial, and local laws leaves this species at continued risk of
habitat loss and degradation in British Columbia, Washington, and
Oregon. In many cases, laws and regulations that pertain to retention
and restoration of wetland and riverine areas are a no-management
(i.e.,
[[Page 51707]]
avoidance) approach, or are designed to be beneficial to fish species
(principally salmonids), resulting in the elimination or degradation of
Oregon spotted frog early-seral habitat. In other cases, no regulations
address threats related to the draining or development of wetlands or
hydrologic modifications, which can also eliminate or degrade Oregon
spotted frog habitat. Therefore, degradation of habitat is ongoing
despite regulatory mechanisms, and these mechanisms have been
insufficient to significantly reduce or remove the threats to the
Oregon spotted frog.
Many of the Oregon spotted frog breeding locations are small and
isolated from other breeding locations. Due to their fidelity to
breeding locations and vulnerability to fluctuating water levels,
predation, and low overwinter survival, Oregon spotted frogs can
experience rapid population turnovers that they may not be able to
overcome. Low connectivity among occupied sub-basins and among breeding
locations within a sub-basin, in addition to small population sizes,
contributes to low genetic diversity within genetic groups and high
genetic differentiation among genetic groups. Oregon spotted frogs in
every occupied sub-basin are subject to more than one stressor, such as
loss or reduced quality of habitat and predation. Therefore, the
species may be more susceptible to the synergistic effects of combined
threats, which may be exacerbated by climate change. The threat to
Oregon spotted frogs from other natural or manmade factors is occurring
throughout the entire range of the species, and the population-level
impacts are expected to continue into the foreseeable future.
All of the known Oregon spotted frog occupied sub-basins are
currently affected by one or more of these threats, which reduce the
amount and quality of available breeding, summer, and overwintering
habitat. While the risk to an individual site from each of these
factors may vary, the cumulative risk of these threats to each site is
high. This scenario is reflected in declining and/or small populations,
which constitute the majority the Oregon spotted frog's remaining
distribution. We find that Oregon spotted frogs are likely to become
endangered throughout all or a significant portion of their range
within the foreseeable future, based on the immediacy, severity, and
scope of the threats described above. However, the best scientific and
commercial information does not indicate at the present time that the
existing threats are of such a great magnitude that Oregon spotted
frogs are in immediate danger of extinction. Threats are not
geographically concentrated in any portions of the species' range, and
the species is extant and redundant at a number of localities within 13
of 15 sub-basins within British Columbia, Washington, and Oregon. One
extant population remains in each of the Lower Deschutes River and
Middle Fork Willamette sub-basins in Oregon. Egg mass surveys continue
to document reproducing adults in most areas, although in at least two
locations within the current range, Oregon spotted frogs may no longer
be extant (i.e., the Maintenance Detachment Aldergrove site in British
Columbia and the 110th Avenue site at Nisqually NWR in Washington).
The Act defines an endangered species as any species that is ``in
danger of extinction throughout all or a significant portion of its
range'' and a threatened species as any species ``that is likely to
become endangered throughout all or a significant portion of its range
within the foreseeable future.'' We find that the Oregon spotted frog
is likely to become endangered throughout all or a significant portion
of its range within the foreseeable future, based on the immediacy,
severity, and scope of the threats described above. The best scientific
and commercial information does not indicate at the present time that
the existing threats are of such a great magnitude that Oregon spotted
frogs are in immediate danger of extinction, but we conclude that it is
likely to become so in the foreseeable future. Therefore, on the basis
of the best available scientific and commercial information, we
determine that the Oregon spotted frog meets the definition of
threatened in accordance with sections 3(20) and 4(a)(1) of the Act.
Significant Portion of the Range
The Act defines an endangered species as any species that is ``in
danger of extinction throughout all or a significant portion of its
range'' and a threatened species as any species ``that is likely to
become endangered throughout all or a significant portion of its range
within the foreseeable future.'' A major part of the analysis of
``significant portion of the range'' requires considering whether the
threats to the species are geographically concentrated in any way. If
the threats are essentially uniform throughout the species' range, then
no portion is likely to warrant further consideration.
The best available data suggest that, under current conditions,
Oregon spotted frogs will likely continue to decline toward extinction.
Having already determined that the Oregon spotted frog is a threatened
species throughout its range, we considered whether threats may be so
concentrated in some portion of its range that, if that portion were
lost, the entire species would be in danger of extinction. We reviewed
the entire supporting record for the status review of this species with
respect to the geographic concentrations of threats, and the
significance of portions of the range to the conservation of the
species. Oregon spotted frogs currently occupy 15 sub-basins that are
widely distributed, such that a catastrophic event in one or more of
the sub-basins would not extirpate Oregon spotted frogs throughout
their range. Based on our five-factor analysis of threats throughout
the range of the Oregon spotted frog, we found that threats to the
survival of the species occur throughout the species' range and are not
significantly concentrated or substantially greater in any particular
portion of their range. Therefore, we find that there is no significant
portion of the Oregon spotted frog's range that may warrant a different
status. Therefore, the species as a whole is not presently in danger of
extinction, and does not meet the definition of an endangered species
under the Act.
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened under the Act include recognition, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition through listing results in public awareness, and
conservation by Federal, State, Tribal, and local agencies; private
organizations; and individuals. The Act encourages cooperation with the
States and requires that recovery actions be carried out for all listed
species. The protection required by Federal agencies and the
prohibitions against certain activities are discussed, in part, below.
The primary purpose of the Act is the conservation of endangered
and threatened species and the ecosystems upon which they depend. The
ultimate goal of such conservation efforts is the recovery of these
listed species, so that they no longer need the protective measures of
the Act. Subsection 4(f) of the Act requires the Service to develop and
implement recovery plans for the conservation of endangered and
threatened species. The recovery planning process involves the
identification of actions that are necessary to halt or reverse the
species' decline by addressing the threats to its survival and
recovery. The goal of this process is to restore listed species to a
point where they are secure, self-
[[Page 51708]]
sustaining, and functioning components of their ecosystems.
Recovery planning includes the development of a recovery outline
after a species is listed and preparation of a draft and final recovery
plan. The recovery outline guides the immediate implementation of
urgent recovery actions and describes the process to be used to develop
a recovery plan. Revisions of the plan may be done to address
continuing or new threats to the species, as new substantive
information becomes available. The recovery plan identifies site-
specific management actions that set a trigger for review of the five
factors that control whether a species remains listed or may be
delisted, and methods for monitoring recovery progress. Recovery plans
also establish a framework for agencies to coordinate their recovery
efforts and provide estimates of the cost of implementing recovery
tasks. Recovery teams (composed of species experts, Federal and State
agencies, nongovernmental organizations, and stakeholders) are often
established to develop recovery plans. When completed, the recovery
outline, draft recovery plan, and the final recovery plan will be
available on our Web site (http://www.fws.gov/endangered), or from our
Washington Fish and Wildlife Office (see FOR FURTHER INFORMATION
CONTACT).
Implementation of recovery actions generally requires the
participation of a broad range of partners, including other Federal
agencies, States, Tribes, nongovernmental organizations, businesses,
and private landowners. Examples of recovery actions include habitat
restoration (e.g., restoration of native vegetation), research, captive
propagation and reintroduction, and outreach and education. The
recovery of many listed species cannot be accomplished solely on
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires
cooperative conservation efforts on private, State, and Tribal lands.
Following publication of this final listing rule, funding for
recovery actions will be available from a variety of sources, including
Federal budgets, State programs, and cost share grants for non-Federal
landowners, the academic community, and nongovernmental organizations.
In addition, pursuant to section 6 of the Act, the States of
Washington, Oregon, and California will be eligible for Federal funds
to implement management actions that promote the protection or recovery
of the Oregon spotted frog. Information on our grant programs that are
available to aid species recovery can be found at: http://www.fws.gov/grants.
Please let us know if you are interested in participating in
recovery efforts for the Oregon spotted frog. Additionally, we invite
you to submit any new information on this species whenever it becomes
available and any information you may have for recovery planning
purposes (see FOR FURTHER INFORMATION CONTACT).
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is listed as an endangered or
threatened species and with respect to its critical habitat, if any is
designated. Regulations implementing this interagency cooperation
provision of the Act are codified at 50 CFR part 402. If a species is
listed subsequently, section 7(a)(2) of the Act requires Federal
agencies to ensure that activities they authorize, fund, or carry out
are not likely to jeopardize the continued existence of the species or
destroy or adversely modify its critical habitat. If a Federal action
may affect a listed species or its critical habitat, the responsible
Federal agency must enter into consultation with the Service.
Federal agency actions within the species' habitat that may require
conference or consultation or both as described in the preceding
paragraph include, but are not limited to, management and any other
landscape-altering activities on Federal lands administered by the U.S.
Fish and Wildlife Service, USFS, BLM, and Joint Base Lewis McChord;
actions funded or carried out by NRCS, USDA Rural Development, USDA
Farm Service Agency, and USDA APHIS; issuance of section 404 Clean
Water Act permits by the Corps; construction and maintenance of roads
or highways by the Federal Highway Administration; construction and
maintenance renewable and alternative energy projects and right-of-way
corridors under U.S. Department of Energy and Bonneville Power
Administration; and activities and infrastructure construction and
maintenance associated with water storage and delivery under the
purview of Bureau of Reclamation.
Examples of other activities conducted, regulated, or funded by
Federal agencies that may affect listed species or their habitat
include, but are not limited to:
(1) Vegetation management such as planting, grazing, burning,
mechanical treatment, and/or application of pesticides adjacent to or
in Oregon spotted frog habitat;
(2) Water manipulation, such as flow management, water diversions,
or canal dredging or piping;
(3) Recreation management actions such as development of
campgrounds or boat launches adjacent to or in Oregon spotted frog
habitat;
(4) River restoration, including channel reconstruction, placement
of large woody debris, vegetation planting, reconnecting riverine
floodplain, or gravel placement adjacent to or in Oregon spotted frog
habitat;
(5) Pond construction; and
(6) Import, export, or trade of the species.
Under section 4(d) of the Act, the Service has discretion to issue
regulations that we find necessary and advisable to provide for the
conservation of threatened species. The Act and its implementing
regulations set forth a series of general prohibitions and exceptions
that apply to threatened wildlife. The prohibitions of section 9(a)(1)
of the Act, as applied to threatened wildlife and codified at 50 CFR
17.31, make it illegal for any person subject to the jurisdiction of
the United States to take (which includes harass, harm, pursue, hunt,
shoot, wound, kill, trap, capture, or collect; or to attempt any of
these) threatened wildlife within the United States or on the high
seas. In addition, it is unlawful to import; export; deliver, receive,
carry, transport, or ship in interstate or foreign commerce in the
course of commercial activity; or sell or offer for sale in interstate
or foreign commerce any listed species. It is also illegal to possess,
sell, deliver, carry, transport, or ship any such wildlife that has
been taken illegally. Certain exceptions apply to employees of the
Service, the National Marine Fisheries Service, other Federal land
management agencies, and State conservation agencies.
We may issue permits to carry out otherwise prohibited activities
involving threatened wildlife under certain circumstances. Regulations
governing permits are codified at 50 CFR 17.32. With regard to
threatened wildlife, a permit may be issued for the following purposes:
For scientific purposes, to enhance the propagation or survival of the
species, and for incidental take in connection with otherwise lawful
activities. There are also certain statutory exemptions from the
prohibitions, which are found in sections 9 and 10 of the Act.
It is our policy, as published in the Federal Register on July 1,
1994 (59 FR 34272), to identify to the maximum extent practicable at
the time a species is listed, those activities that would or would not
constitute a violation of
[[Page 51709]]
section 9 of the Act. The intent of this policy is to increase public
awareness of the effect of a listing on proposed and ongoing activities
within the range of listed species. At this time, we are unable to
identify specific activities that would not be considered to result in
a violation of section 9 of the Act because the Oregon spotted frog
occurs in a variety of habitat conditions across its range and it is
likely that site specific conservation measures may be needed for
activities that may directly or indirectly affect the species. The
following activities could potentially result in a violation of section
9 of the Act; this list is not comprehensive:
(1) Introduction of nonnative species that compete with or prey
upon the Oregon spotted frog, such as bullfrogs, green frogs, or warm
or cold water fishes to the States of Washington, Oregon, or
California;
(2) Modification of the wetted area or removal or destruction of
emergent aquatic vegetation in any body of water in which the Oregon
spotted frog is known to occur; and
(3) Discharge of chemicals into any waters in which the Oregon
spotted frog is known to occur.
Questions regarding whether specific activities would constitute a
violation of section 9 of the Act should be directed to the Washington
Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).
Under section 4(d) of the Act, the Secretary has discretion to
issue such regulations as he deems necessary and advisable to provide
for the conservation of threatened species. Our implementing
regulations (50 CFR 17.31) for threatened wildlife generally
incorporate the prohibitions of section 9 of the Act for endangered
wildlife, except when a rule promulgated pursuant to section 4(d) of
the Act has been issued with respect to a particular threatened
species. In such a case, the general prohibitions in 50 CFR 17.31 would
not apply to that species, and instead, the 4(d) rule would define the
specific take prohibitions and exceptions that would apply for that
particular threatened species, which we consider necessary and
advisable to conserve the species. The Secretary also has the
discretion to prohibit by regulation with respect to a threatened
species any act prohibited by section 9(a)(1) of the Act. Exercising
this discretion, which has been delegated to the Service by the
Secretary, the Service has developed general prohibitions that are
appropriate for most threatened species in 50 CFR 17.31 and exceptions
to those prohibitions in 50 CFR 17.32.
We have not proposed to promulgate a rule under section 4(d) of the
Act for the Oregon spotted frog, and as a result, all of the section 9
prohibitions, including the ``take'' prohibitions, will apply to the
Oregon spotted frog.
Required Determinations
National Environmental Policy Act (42 U.S.C. 4321 et seq.)
We have determined that environmental assessments and environmental
impact statements, as defined under the authority of the National
Environmental Policy Act (42 U.S.C. 4321 et seq.), need not be prepared
in connection with listing a species as an endangered or threatened
species under the Endangered Species Act. We published a notice
outlining our reasons for this determination in the Federal Register on
October 25, 1983 (48 FR 49244).
Government-to-Government Relationship With Tribes
In accordance with the President's memorandum of April 29, 1994
(Government-to-Government Relations With Native American Tribal
Governments; 59 FR 22951), Executive Order 13175 (Consultation and
Coordination With Indian Tribal Governments), and the Department of the
Interior's manual at 512 DM 2, we readily acknowledge our
responsibility to communicate meaningfully with recognized Federal
Tribes on a government-to-government basis. In accordance with
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights,
Federal-Tribal Trust Responsibilities, and the Endangered Species Act),
we readily acknowledge our responsibilities to work directly with
tribes in developing programs for healthy ecosystems, to acknowledge
that tribal lands are not subject to the same controls as Federal
public lands, to remain sensitive to Indian culture, and to make
information available to tribes. Oregon spotted frogs are not known to
occur on Tribally owned lands. However, we provided information on our
proposed and final listing rules to Tribal governments in Oregon and
Washington where known Oregon spotted frog occurrences overlap with
Tribal interests.
References Cited
A complete list of references cited in this rulemaking is available
on the Internet at http://www.regulations.gov and upon request from the
Washington Fish and Wildlife Office (see FOR FURTHER INFORMATION
CONTACT).
Authors
The primary authors of this package are the staff members of the
Washington Fish and Wildlife Office, Oregon Fish and Wildlife Office--
Bend Field Office, and Klamath Falls Fish and Wildlife Office.
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Regulation Promulgation
Accordingly, we amend part 17, subchapter B of chapter I, title 50
of the Code of Federal Regulations, as follows:
PART 17--[AMENDED]
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless
otherwise noted.
0
2. Amend Sec. 17.11(h) by adding an entry for ``Frog, Oregon spotted''
to the List of Endangered and Threatened Wildlife in alphabetical order
under AMPHIBIANS to read as set forth below:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
[[Page 51710]]
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Species Vertebrate
------------------------------------------------------ population where Critical Special
Historic range endangered or Status When listed habitat rules
Common name Scientific name threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Amphibians
* * * * * * *
Frog, Oregon spotted............ Rana pretiosa...... Canada (BC); U.S.A. Entire............. T 846 NA NA
(WA, OR, CA).
* * * * * * *
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* * * * *
Dated: July 22, 2014.
Stephen Guertin,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2014-20059 Filed 8-28-14; 8:45 am]
BILLING CODE 4310-55-P