[Federal Register Volume 76, Number 192 (Tuesday, October 4, 2011)]
[Proposed Rules]
[Pages 61298-61307]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-25595]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[FWS-R1-ES-2008-0048; MO 92210-0-0008 B2]
Endangered and Threatened Wildlife and Plants; 12-Month Finding
on a Petition To List the Lake Sammamish Kokanee Population of
Oncorhynchus nerka as an Endangered or Threatened Distinct Population
Segment
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of a 12-month petition finding.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
12-month finding on a petition to list the Lake Sammamish kokanee,
Oncorhynchus nerka, as an endangered or threatened species under the
Endangered Species Act of 1973, as amended (Act). After review of all
available scientific and commercial information, we find that the Lake
Sammamish kokanee population is not a listable entity under the Act
and, therefore, listing is not warranted. We ask the public to continue
to submit to us any new information that becomes available concerning
the taxonomy, biology, ecology, and status of Lake Sammamish kokanee,
and to support cooperative conservation efforts for this population.
DATES: The finding announced in this document was made on October 4,
2011.
ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at docket number [FWS-R1-ES-2008-0048]. Supporting
documentation we used to prepare this finding is available for public
inspection, by appointment, during normal business hours at the U.S.
Fish and Wildlife Service, Washington Fish and Wildlife Office, 510
Desmond Drive, SE., Suite 102, Lacey, WA 98503. Please submit any new
information, materials, comments, or questions concerning this finding
to the above address.
FOR FURTHER INFORMATION CONTACT: Ken Berg, Manager, Project Leader,
Washington Fish and Wildlife Office, U.S. Fish and Wildlife Service
(see
[[Page 61299]]
ADDRESSES) by telephone at 360-753-6039; or by facsimile at 360-753-
9405. Persons who use a telecommunications device for the deaf (TDD),
may call the Federal Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(B) of the Endangered Species Act of 1973, as
amended (Act) (16 U.S.C. 1531 et seq.) requires that, for any petition
to revise the Lists of Endangered and Threatened Wildlife and Plants
that contains substantial scientific or commercial information that
listing the species may be warranted, we make a finding within 12
months of the date of receipt of the petition on whether the petitioned
action is: (a) Not warranted; (b) warranted; or (c) warranted, but
immediate proposal of a regulation implementing the petitioned action
is precluded by other pending proposals to determine whether species
are threatened or endangered, and expeditious progress is being made to
add or remove qualified species from the Lists of Endangered and
Threatened Wildlife and Plants. Section 4(b)(3)(C) of the Act requires
that we treat a petition for which the requested action is found to be
warranted but precluded as though resubmitted on the date of such
finding; that is, requiring a subsequent finding to be made within 12
months. Such 12-month findings must be published in the Federal
Register. This notice constitutes our 12-month finding for the petition
to list the Lake Sammamish population of kokanee.
Previous Federal Actions
On July 9, 2007, we received a petition from Trout Unlimited; the
City of Issaquah, Washington; King County, Washington; People for Puget
Sound; Save Lake Sammamish; the Snoqualmie Tribe; and the Wild Fish
Conservancy requesting that all wild, indigenous, naturally spawned
kokanee (Oncorhynchus nerka) in Lake Sammamish, Washington, be listed
as a threatened or endangered species under the Endangered Species Act.
The petition clearly identified itself as such and included the
requisite identification information for the petitioners, as required
in 50 CFR 424.14(a). Included in the petition was supporting
information regarding the species' declining numbers, reduced
productivity, a decline in the quantity and quality of their habitat,
and narrowing temporal, spatial, and genetic diversity. We acknowledged
the receipt of the petition in a letter to the petitioners dated
September 24, 2007, and stated that we anticipated making an initial
finding within 90 days as to whether the petition contained substantial
information indicating that the action may be warranted. We also
advised that our initial review of the petition did not indicate that
an emergency listing situation existed, but that if conditions changed
and we determined that emergency listing was warranted, an emergency
rule may be developed. Funding became available to work on the 90-day
finding on October 1, 2007. We published a notice of 90-day finding in
the Federal Register on May 6, 2008 (73 FR 24915), determining that the
petition presented substantial scientific information indicating that
listing the Lake Sammamish kokanee may be warranted, and that we were
initiating a status review of the species and opening a 60-day public
comment period. On December 14, 2009, we received a 60-day notice of
intent to sue from the Center for Biological Diversity over the
Service's failure to make a 12-month finding as required by the Act
(CBD v. Ken Salazar, U.S. District Court, District of Oregon, CV 10-
0176-JO). A complaint was filed with the court on February 17, 2010.
We received comments and information from the following individuals
and organizations in response to the 90-day finding: King County
Department of Natural Resources and Parks, James Mattila, Trout
Unlimited, Snoqualmie Indian Tribe, Save Lake Sammamish, Friends of
Pine Lake Creek, Washington Department of Fish and Wildlife, and Sno-
King Watershed Council. We have fully considered the comments and
information presented by these commentors in this finding. In addition,
during our status assessment, we generally found that much more
information was available on the status of sockeye populations,
compared to kokanee populations at the rangewide scale, which may be
related to the commercial importance of sockeye salmon. To evaluate
whether the population of kokanee in Lake Sammamish qualifies as a
listable entity under the Act, we must first determine if it satisfies
the criteria for being a distinct population segment. Under the Policy
Regarding the Recognition of Distinct Vertebrate Population Segments
(DPS Policy), which was published in the Federal Register on February
7, 1996 (61 FR 4722), we are required to evaluate the discreteness and
significance of the petitioned entity against the rest of the taxon, at
the rangewide scale.
Species Information
Taxonomy and Range
Oncorhynchus nerka (Order Salmoniformes, Family Salmonidae), is
native to watersheds in the north Pacific from southern Kamchatka to
Japan in the western Pacific, and from Alaska to the Columbia River in
North America (Page and Burr 1991, p. 52; Taylor et al. 1996, pp. 402-
403). There are three life forms of this species, which are discussed
in greater detail below: (1) Anadromous (ocean-going) sockeye; (2)
residual sockeye, and (3) kokanee. The kokanee life form was at one
time thought to be a separate subspecies (Oncorhynchus nerka kennerlyi,
Suckley 1861), and that taxonomy continues to be reflected in some
scientific papers and other studies (Robertson 1961; McLellan et al.
2001; Carruth et al. 2000; Maiolie et al. 1996). However, kokanee and
sockeye are formally recognized as the same species (O. nerka) by the
scientific community, and in the integrated taxonomic data system
(ITIS) (http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=161979). Despite their recognized conspecific
status, sympatric populations of sockeye and kokanee (those that occur
in the same or overlapping geographic areas) are biologically and
genetically distinct (Foote et al. 1989, in Young et al. 2004, p. 63).
Based on the best available information, we consider the Lake Sammamish
kokanee population to belong to the species Oncorhynchus nerka.
Kokanee Evolution
All kokanee populations are evolutionarily derived from sockeye
salmon. Sockeye salmon (anadromous Oncorhynchus nerka) give rise to
kokanee over evolutionary timeframes (hundreds to thousands of years)
as a result of isolation or selective pressures related to difficulty
of migration and lake productivity (Wood et al. 2008, pp. 208-210). All
kokanee are at the end of a long chain of events where individuals of
the anadromous sockeye entered a lake and selective pressures founded a
residual sockeye population, then selective pressures or perhaps a
geologic event selected for a kokanee population. The evolution of the
O. nerka forms is unidirectional, and established resident, migratory,
or kokanee forms generally do not create successful progeny of the
other forms (Wood et al. 2008, pp. 209-210).
Taylor et al. (1996, pp. 411-414), found multiple episodes of
independent divergence between sockeye and kokanee throughout their
current range.
[[Page 61300]]
As ancestral anadromous sockeye populations expanded to new river
systems, those that could not access the marine environment on a
regular basis evolved into the non anadromous kokanee form or developed
a sympatric population of the non anadromous kokanee form. This has
resulted in native kokanee populations typically being genetically more
similar to their sympatric (occupying the same geographic area without
interbreeding) sockeye populations than to kokanee in other river
systems (Taylor et al. 1996, pp. 401, 413-414). However, there are
exceptions (e.g., Lake Ozette, Washington) where native sympatric
kokanee and sockeye populations were determined to be genetically
dissimilar, which suggests in these cases that they were established
through a different founding event (Winans et al. 1996, pp. 655-656).
Differences Between Sockeye and Kokanee
Sockeye salmon are primarily anadromous, migrating to the Pacific
Ocean following hatching and rearing in freshwater. Most populations
are associated with a natal lake. They spend 2 to 3 years in marine
waters before returning to freshwater environments to spawn and die.
Some progeny within each sockeye population may remain in freshwater
throughout their lifecycle and are called ``residual sockeye'' or
``residuals'' (Gustafson et al. 1997, p. 20). Unlike sockeye, kokanee
are non anadromous and spend their entire lives in freshwater habitats
(Meehan and Bjorn 1991, pp. 56-57). Ricker (1938) first used the terms
``residual sockeye'' and ``residuals'' to refer to these resident, non
migratory progeny of anadromous salmon (Quinn 2005, p. 210). These
``residuals'' were much smaller at maturity than the anadromous fish
because growing conditions in the lakes are generally poorer than those
at sea (Quinn 2005, p. 210). Wood (1995) hypothesizes that the
evolution of sockeye populations may proceed from postglacial
colonization by ocean-type fish, to lake-type populations if a suitable
lake is present, and then to kokanee if there is some combination of
good growing conditions and an arduous migration (Quinn 2005, pp. 301-
302). Kokanee young are spawned in freshwater streams and subsequently
migrate to a nursery lake (Burgner 1991, pp. 35-37), where they remain
until maturity. In some cases kokanee are spawned along the shoreline
of the nursery lake itself (Scott and Crossman 1973, p.168). When
mature, they return to natal freshwater streams to spawn and die,
typically around age four. Sympatric kokanee and sockeye populations
are typically temporally or spatially separated. In cases where they
are not, assortative mating by body size usually leads to assortative
mating by type (Gustafson et al. 1997, p. 30). Said another way,
sockeye are typically larger and spawn with other sockeye, while
kokanee are smaller and spawn with other kokanee.
Both kokanee and anadromous sockeye turn from silver to bright red
during maturation, while the head is olive green and the fins are
blackish red (Craig and Foote 2001, p. 381). Typically, resident or
``residual sockeye'' (progeny of anadromous sockeye that do not migrate
to sea but are not kokanee) turn from silver to green (Foote et al.
2004, p. 70). Although adult kokanee resemble sockeye salmon, they have
significant morphological and physiological differences. Kokanee are
more efficient at extracting carotinoids from food resources; have
higher gill raker counts, which is known to be an inherited trait; and
are normally smaller in size at maturity than sockeye because they are
confined to freshwater environments, which are less productive than the
ocean (Burgner 1991, p. 59; Gustafson et al. 1997, p. 29; Craig and
Foote 2001, p. 387; Leary et al. 1985 in Wood 1995, p. 203). Kokanee
maintain a constant egg size, while increasing egg number with
increasing body size; sockeye increase both egg number and egg size
with increasing body size. It is thought that this characteristic may
be related to the less energetically costly kokanee spawning migrations
and the smaller particle size of spawning gravel that can be exploited
(McGurk 2000, p. 1802). Other studies have demonstrated that under-
yearling sockeye salmon exhibit superior swimming ability compared to
kokanee (Taylor and Foote 1991). Further, although kokanee appear to
have maintained some degree of seasonal adaptation to saltwater, which
is part of the smoltification process of anadromous salmonids (complex
physiological changes that enable juvenile salmon to make the
transition from freshwater to saltwater), genetically there are
significant differences in the timing (delayed) and duration (short-
lived) compared to sockeye (Foote et al. 1992, pp. 106-108).
Sockeye and Kokanee Distribution
Sockeye occur in watersheds in the north Pacific from southern
Kamchatka to Japan in the western Pacific, and from Alaska to the
Columbia River in North America (Page and Burr 1991, p. 52; Taylor et
al. 1996, pp. 402-403). Sockeye salmon of Canadian origin generally
remain east of the International Dateline and south of the Aleutian
Islands, while those from Asia originate in freshwater habitats from
Cape Navarin Peninsula in the Bering Sea to north of Sakhalin Island in
the Sea of Okhotsk. Most sockeye from Canadian rivers spend 2 years in
the ocean, while those from other rivers spend 1, 3 or 4 years (Hart
1973, p. 121).
Native populations of kokanee, each associated with a specific
nursery lake, likely occurred historically over most of the range of
sockeye salmon within the Columbia River to the Yukon River systems.
Native kokanee populations are not widespread in Alaska (McGurk 2000,
p. 1801) or Asia (McPhail 2007, p. 288). There are said to be well over
500 kokanee populations in British Columbia (B.C.) (McPhail 2007, p.
295). No native kokanee are known from the B.C. portion of the Yukon
River (B.C. Ministry of Fisheries 1998, p. 17), and although
introduction activities have spread kokanee throughout the province,
only two natural populations are known from the Mackenzie River system
(McPhail 2007, p. 289). Kokanee have been widely introduced across
North America, including areas outside their larger geographic
distribution and farther inland in States and provinces where they
occur naturally (Scott and Crossman 1973, p. 167).
Sammamish River/Lake Sammamish Watershed Kokanee Population Groupings
Lake Sammamish kokanee distribution (the petitioned entity): Lake
Washington is the dominant feature of the greater Lake Washington/Lake
Sammamish Basin and is fed by two major drainage systems. The Cedar
River watershed at the south end of the lake, and the Sammamish River/
Lake Sammamish watershed at the north end of the lake. Surface water
discharge from Lake Sammamish is by way of the Sammamish River at the
north end of the lake, which ultimately flows into Lake Washington. The
four major tributaries that discharge into the Sammamish River are
Swamp Creek, North Creek, Little Bear Creek, and Bear Creek. The major
tributary to Lake Sammamish is Issaquah Creek, which enters at the
south end of the lake and contributes approximately 70 percent of the
inflow to the lake (Kerwin 2001, p. 425). Native kokanee historically
spawned in tributaries located throughout Lake Washington and Lake
Sammamish. Although the Sammamish River and Cedar River (Walsh Lake)
drainages have been included within the current distribution of native
kokanee in prior assessments (Gustafson
[[Page 61301]]
et al. 1997, p. 123; Berge and Higgins 2003, p. 3), their current
spawning distribution in the Lake Washington/Lake Sammamish Basin
appears to be limited to portions of the Lake Sammamish drainage. For
the purposes of this finding, we are analyzing a petitioned entity that
includes the native kokanee population found in the Lake Sammamish
drainage.
Although the major tributary to Lake Sammamish is Issaquah Creek,
there are also several smaller tributaries to Lake Sammamish used for
spawning by kokanee, including Ebright Creek, Pine Lake Creek, Laughing
Jacobs Creek, and Lewis Creek (Berge and Higgins 2003, p. 5). Kokanee
in the Sammamish River/Lake Sammamish watershed (referred to by the
petitioners as the Lake Sammamish population) are separated into three
groups: (1) Summer/early-run; (2) fall/middle-run; and, (3) winter/
late-run, based on spawn timing and location (Berge and Higgins 2003,
p. 3; Young et al. 2004, p. 66). Summer/early-run kokanee spawn during
late summer (August through September) in Issaquah Creek, and are the
only run of kokanee known to spawn in that creek, although introduced
sockeye salmon spawn there in October. Fall/middle-run kokanee spawn in
late September through November, primarily in larger Sammamish River
tributaries including Swamp Creek, North Creek, Bear Creek, Little Bear
Creek, and Cottage Lake Creek (Berge and Higgins 2003, pp. 21-25).
Winter/late-run kokanee spawn from late fall into winter (October
through January) in Lake Sammamish tributaries including Lewis Creek,
Ebright Creek, and Laughing Jacobs Creek (Berge and Higgins 2003, pp.
26-29). Some winter/late-run spawning kokanee have also been recorded
in Vasa Creek, Pine Lake (Trout Unlimited et al. 2007, p. 9), and
Tibbetts Creek (Berge and Higgins 2003, pp. 5, 30) in the recent past.
Berge and Higgins (2003, p. 5) identified George Davis, Zaccuse, and
Alexander's Creeks as part of the historical spawning distribution for
winter/late-run kokanee. On at least one occasion, kokanee, presumed to
be winter/late-run based on spawn timing, were observed spawning in
Lake Sammamish near the mouth of Ebright Creek (Berge and Higgins 2003,
p. 33), suggesting that some degree of beach spawning may also occur
within the lake. More recently, what appears to be winter/late-run
kokanee have been observed entering the lower reach of George Davis
Creek at dusk (Nickel 2009) but then retreating back to Lake Sammamish
during the day apparently without spawning. This may further indicate
possible beach spawning within the lake.
Sammamish River/Lake Sammamish Watershed Kokanee Escapement Surveys
Summer/early-run: Berggren (1974, p. 9) and Pfeifer (1995, pp. 8-9,
21-22) report escapements (the number of fish arriving at a natal
stream or river to spawn) of summer/early-run Issaquah Creek kokanee
numbering in the thousands during the 1970s. Since 1980, the escapement
of early-run kokanee in Issaquah Creek has ``plummeted dramatically''
(Berge and Higgins 2003, p. 18). Between 1998 and 2001, only three
summer/early-run kokanee redds (gravel nests of fish eggs) were
observed in Issaquah Creek (Berge and Higgins 2003, p. 18). The last
time summer/early-run kokanee were observed was during the summer of
2000, when only two individuals were recorded (Washington Trout 2004,
p. 3). In July 2001 and 2002, the Washington Department of Fish and
Wildlife installed a fish weir across Issaquah Creek in an attempt to
capture all migrating summer/early-run kokanee and spawn them in a
hatchery for a supplementation program. No kokanee were observed or
captured (WDFW 2002, pp. 5-7). Further, there were no summer/early-run
kokanee observed during spawner surveys conducted in 2003 (Washington
Trout 2004, p. 2), leading King County and Washington Department of
Fish and Wildlife biologists to conclude that the summer/early-run is
functionally extinct (Berge and Higgins 2003, p. 33; Jackson 2006, p.
1).
Fall/middle-run: In the 1940s, the fall/middle-run kokanee was
estimated to number from 6,000 to as many as 30,000 spawners in Bear
Creek, a tributary to the Sammamish River (Connor et al. 2000, pp. 13-
14), although these estimates are confounded by the high numbers of
out-of-basin and in-basin kokanee introductions during this time
period. Between 1917 and 1969, more than 44 million kokanee were
introduced into Bear Creek and its tributaries, 35 million of which
originated from Lake Whatcom in northwestern Washington (Gustafson et
al. 1997, pp. 3-113). However, the introduced kokanee were unable to
persist, and by the 1970s the native kokanee fall/middle-run was also
considered extinct by biologists from Washington Department of Game
(now part of Washington Department of Fish and Wildlife) (Fletcher
1973, p. 1).
Winter/late-run: From 1996 to 2006, the winter/late-run kokanee
have had highly variable spawner returns with returns as low as 64 in
1997, and as high as 4,702 in 2003 (Trout Unlimited et al. 2007, p.
18). Annual spawner returns averaged 946 fish, with a median return of
594 fish during this period (Trout Unlimited et al. 2007, p. 16). From
2004 to 2007, the average spawner return was 463 fish, although in two
of the four spawning streams currently used by the winter/late-run
(Laughing Jacobs Creek and Pine Lake Creek), there were fewer than 70
fish counted annually in each stream (Jackson 2009). In 2008, the
estimated spawner return was 42 individuals with none observed in Pine
Lake Creek and only one kokanee observed in Laughing Jacobs Creek
(Jackson 2009, pp. 1-6). This represented the lowest escapement for
this population on record, although in 2009 the estimated spawner
return was 1,655 individuals, which was the largest escapement recorded
since 2003 (Jackson 2010, p. 11). The longest accessible spawning
stream currently used by the winter/late-run, Lewis Creek, is 0.75 mile
(mi) (1.2 kilometers (km)), and the combined spawning reaches of the
core spawning streams (Lewis Creek, Laughing Jacobs Creek, and Ebright
Creek) total less than 1.0 mile (1.6 km) (Jackson 2006, p. 5). Winter/
late run propagation efforts have recently been implemented, and are
described below.
Winter/Late Run Propagation Efforts
In the fall of 2009, approximately 35,000 eggs were harvested from
mature kokanee collected from Lewis, Ebright, and Laughing Jacobs
Creeks by teams from the Issaquah Creek salmon hatchery. The eggs were
shipped to the Cedar River and Chambers Creek hatcheries in Washington
State for development into fry, for use in supplementing the native
kokanee population in Lake Sammamish. In March 2010, approximately
14,000 kokanee fry were released into Lewis, Ebright, and Laughing
Jacobs Creeks; another release of 20,000 fry into the same creeks was
done on April 14, 2010. The eventual success of these efforts remains
to be determined (http://www.issaquahpress.com/2010/04/20/the-fish-journal-bar-codes-help-kokanee-salmon-in-their-survival/#more-21481).
Sockeye and Kokanee Abundance Trends
Quinn 2005 (p. 319) indicated the estimated average annual
abundance of sockeye salmon per region (catch and escapement of wild
and hatchery fish) from 1981 to 2000 to be 83 million fish (Japan 0.0
million, Russia 10.0 million, Western Alaska 50.4 million, Central
[[Page 61302]]
Alaska 20.3 million, and Southeast Alaska to California 19.3 million).
The estimated catch and escapement of North American sockeye salmon
from 1951 through 2001 was 51.4 million fish from 1,400 populations,
averaging approximately 37,000 fish per population (Quinn 2005, p.
321).
Sockeye populations inhabiting the southern portions of their range
are in decline, whereas those in the northerly regions are generally
stable. In southwestern British Columbia, one-third of the sockeye
spawning runs known since the early 1950s have been lost or have
decreased to such low numbers that spawners are not consistently
monitored (Ridell 1993, in Wood 1995, p. 195). These trends in number
and magnitude of spawning runs imply a loss of genetic diversity,
through the loss of both locally adapted subpopulations and genetic
variation due to low effective population sizes (Wood 1995, p. 195).
Subpopulations in the Hecata Strait-Queen Charlotte Sound, Georgia
Basin/Vancouver Island Area, Skeena River and Fraser River, decreased
in abundance considerably over the last three generations. Towards the
northern end of their distribution, sockeye were generally
characterized by stable-to-increasing trends in adult abundance. There
were several notable exceptions, however, to the north-to-south risk
gradient, including subpopulations in the Columbia and in eastern
Washington State. Many of these are supported through some level of
artificial enhancement, however, which may mask declines in wild
populations (Rand 2008 (IUCN Red List Supporting Documentation, O.
nerka, (http://www.iucnredlist.org/apps/redlist/details/135301/0)).
Although Fraser River stocks as well as other West Coast sockeye
salmon stocks had record returns in 2010 (Northwest Indian Fisheries
Commission (NWIFC 2010, p. 1) (http://nwifc.org/2010/09/large-fraser-sockeye-run-doesnt-make-up-for-decades-of-poor-fishing/), prior to this
year most Fraser River stocks have exhibited declining trends in
productivity beginning as early as 1960 (Fisheries and Oceans Canada
(DFO) 2010, p. 1). Following returns are expected to again be poor for
the next 3 years (NWIFC 2010, p. 1). The three factors that likely
contributed to this record return are:
(1) Large number of offspring resulting from the 6th largest
spawning escapement since 1952 as a result of reduced fisheries in
2006;
(2) Favorable changes in coastal ocean conditions toward cool
temperatures in early 2008 when sockeye that returned in 2010 were
entering the ocean as juveniles; and
(3) the occurrence of a major volcanic eruption in Alaska's
Aleutian Islands in 2008, which resulted in ash fertilizing the ocean
and triggering an algal bloom that possibly enhanced forage value and
availability (Simon Fraser University et al. 2010, p. 2).
The Snake River sockeye Evolutionarily Significant Unit (ESU) has
remained at very low levels of only a few hundred fish, though there
have been recent increases in the number of hatchery-reared fish
returning to spawn. Data quality for the Ozette Lake sockeye ESU make
differentiating between the number of hatchery and natural spawners
difficult, but in either case the size of the population is small,
though possibly growing. Both the Snake River and Ozette Lake ESUs were
listed as endangered and threatened, respectively, under the Act by the
National Marine Fisheries Service (now NOAA Fisheries (NOAAF) under
their ESU policy (56 FR 58612; November 20, 1991), (http://www.nmfs.noaa.gov/pr/species/fish/sockeyesalmon.htm).
We are unaware of average annual abundance records for kokanee;
however, there are said to be well over 500 kokanee populations in
British Columbia (McPhail 2007, p. 295). No native kokanee are known
from the B.C. portion of the Yukon River (B.C. Ministry of Fisheries
1998, p. 17), and although introduction activities have spread kokanee
throughout the province, only two natural populations are known from
the Mackenzie River system (McPhail 2007, p. 289). There are numerous
introduced kokanee populations maintained through hatchery
introductions to support recreational fisheries; kokanee have been
widely introduced across North America, including areas outside their
larger geographic distribution and farther inland in States and
provinces where they occur naturally (Scott and Crossman 1973, p. 167).
Regulatory Context and Agency Responsibilities
National Oceanic and Atmospheric Administration and U.S. Fish and
Wildlife Service Regulatory Jurisdiction under the Endangered Species
Act
Under a 1974 Memorandum of Understanding between the U.S. Fish and
Wildlife Service (FWS) and the National Marine Fisheries Service (now
NOAAF), NOAAF has Act authority over species that either reside the
major portion of their lifetimes in marine waters or spend part of
their lifetime in estuarine waters if the major portion of the
remaining time is spent in marine waters. The FWS has Act authority
over species that spend the major portion of their lifetimes on land or
in fresh water, or that spent part of their lifetimes in estuarine
waters if a major portion of the remaining time is spent on land or in
fresh water (USFWS and NOAA, 1974).
Evolutionarily Significant Unit (ESU) and Distinct Population Segment
(DPS) Policies
In addition to the DPS policy, NOAAF applies the ESU policy (56 FR
58612; November 20, 1991), which was adopted prior to adoption of the
U. S. Fish and Wildlife Service and National Marine Fisheries Service
DPS Policy. The ESU policy considers a stock of Pacific salmon to be a
distinct population and hence a ``species'' under the Act, if it
represents an ESU of the biological species. A stock must satisfy two
criteria to be considered an ESU: (1) It must be substantially
reproductively isolated from other conspecific population units; and
(2) It must represent an important component in the evolutionary legacy
of the species. Under the ESU policy, the evolutionary legacy of a
species is the genetic variability that is a product of past
evolutionary events and which represents the reservoir upon which
future evolutionary potential depends. This criteria would be met for
purposes of the ESU policy if the population contributed substantially
to the ecological/genetic diversity of the species as a whole (i.e.,
extinction of the population would represent a significant loss to the
ecological/genetic diversity of the species). In making this
determination, NOAAF considers whether: (1) The population is
genetically distinct from other conspecific populations; (2) the
population occupies unusual or distinctive habitat; and (3) the
population shows evidence of unusual or distinctive adaptation to its
environment.
NOAAF states that while conclusive evidence does not yet exist
regarding the relationship of resident and anadromous forms of
Oncorhynchus nerka, the available evidence suggests that resident
sockeye and kokanee should not be included in listed anadromous sockeye
ESUs in cases where the strength and duration of reproductive isolation
would provide the opportunity for adaptive divergence in sympatry (64
FR 14530; March 25, 1999). However, NOAAF does include those resident/
residual sockeye within ESUs that spawn with, or adjacent to, sockeye
salmon in the same ESU. NOAAF interprets an ESU as a
[[Page 61303]]
population that is substantially reproductively isolated from
conspecific populations (populations of the same species), which
represents an important component of the evolutionary legacy of the
species. Although Lake Sammamish kokanee are also Pacific salmon, we
have no authority under NOAAF's ESU policy, and have evaluated the
status of the Lake Sammamish kokanee population under the DPS policy.
NOAAF acknowledges the DPS policy takes a somewhat different
approach from the ESU policy to identifying conservation units, which
may result, in some cases, in the identification of different
conservation units. Although the DPS and ESU policies are consistent,
they will not necessarily result in the same delineation of DPSs under
the Act. The statutory term ``distinct population segment'' is not used
in the scientific literature and does not have a commonly understood
meaning therein. NOAAF's ESU policy and the joint DPS policy apply
somewhat different criteria, with the result that their application may
lead to different outcomes in some cases. The ESU policy relies on
``substantial reproductive isolation'' to delineate a group of
organisms, and emphasizes the consideration of genetic and other
relevant information in evaluating the level of reproductive exchange
among potential ESU components. The DPS policy does not rely on
reproductive isolation to determine ``discreteness,'' but rather on the
marked separation of the population segment from other populations of
the same taxon as a consequence of biological factors (61 FR 4725;
February 7, 1996). In addition, the DPS policy also considers the
significance of the discrete population segment to the taxon to which
it belongs, which may produce a different result than the important
evolutionary legacy component considered by NOAAF under the ESU policy.
Distinct Population Segment Policy
Defining a Species Under the Act
Section 3(16) of the Act defines ``species'' to include ``any
subspecies of fish or wildlife or plants, and any distinct population
segment of any species of vertebrate fish or wildlife which interbreeds
when mature.'' Under the DPS policy, three elements are considered in
the decision regarding the establishment and classification of a
population of a vertebrate species as a possible DPS. These are applied
similarly for additions to and removal from the Lists of Endangered and
Threatened Wildlife and Plants. These elements are: (1) The
discreteness of a population segment in relation to the remainder of
the species to which it belongs; (2) the significance of the population
segment to the species to which it belongs; and (3) the population
segment's conservation status in relation to the Act's standards for
listing, delisting, or reclassification. Our regulations provide
further guidance for determining whether a particular taxon or
population is a species for the purposes of the Act: ``The Secretary
shall rely on standard taxonomic distinctions and the biological
expertise of the Department and the scientific community concerning the
relevant taxonomic group'' (50 CFR 424.11).
Kokanee are classified as Oncorhynchus nerka, which is the same
taxonomic species as sockeye salmon. Because the kokanee life history
form itself is not recognized taxonomically as a distinct species or
subspecies, to determine whether the kokanee population in Lake
Sammamish constitutes a DPS, and thus a listable entity under the Act,
we evaluate this population's discreteness and significance with
respect to the taxon to which it belongs (in other words, all
Oncorhynchus nerka (sockeye and kokanee) populations rangewide).
Accordingly, each of the factors evaluated in this finding have been
considered within that context.
Under the DPS policy, a population segment of a vertebrate taxon
may be considered discrete if it satisfies either of the following
factors:
Discreteness Factor 1: The population is markedly separated from
other populations of the same taxon as a consequence of physical,
physiological, ecological, or behavioral factors (quantitative measures
of genetic or morphological discontinuity may provide evidence of this
separation).
Discreteness Factor 2: The population is delimited by international
governmental boundaries within which differences in control of
exploitation, management of habitat, conservation status, or regulatory
mechanisms exist that are significant in light of Section 4(a)(1)(D) of
the Act.
Lake Sammamish Kokanee Discreteness Analysis
Discreteness Factor 1 Examination
Patterns of genetic variation demonstrate that the sockeye and
kokanee within lakes are usually more closely related to each other
than they are to members of their form in other lakes (Foote et al.
1989; Taylor et al. 1996 in Quinn 2005 p. 212). Sympatric kokanee and
sockeye populations are typically temporally or spatially separated;
where that is not the case, assortative mating by body size usually
leads to assortative mating by type (Gustafson et al. 1997, p. 30)
(e.g., sockeye are typically larger and spawn with other sockeye, while
kokanee are smaller and spawn with other kokanee). Historically, a
heritable tendency to remain in a lake system rather than migrate to
sea may have promoted genetic divergence between kokanee and sockeye
forms as they specialized for their freshwater and marine habitat.
These genetic differences would be reinforced by size-specific
preferences for breeding sites, accompanied by the evolution of
isolating mechanisms to reduce interbreeding between the forms (Quinn
p. 210). Kokanee in Lake Sammamish are geographically isolated from
other kokanee, and within Lake Sammamish, kokanee and sockeye are
further isolated by genetic and reproductive behavior (Young et al.
2004, pp. 72-73).
Conclusion: Available data indicate that the Lake Sammamish
population is geographically and reproductively isolated from other
native kokanee and sockeye populations, and genetically and
ecologically discrete from other Oncorhynchus nerka populations,
although a transplanted sockeye population was introduced during the
1930s to the 1950s (NOAA 1997, p. ix).
Discreteness Factor 2 Examination
This factor is not applicable to the discreteness analysis for the
Lake Sammamish kokanee population, as the petitioned Oncorhynchus nerka
population is not delimited by international governmental boundaries
within which differences in control of exploitation, management of
habitat, conservation status, or regulatory mechanisms exist that are
significant in light of Section 4(a)(1)(D) of the Act.
Discreteness Analysis Summary
The kokanee population in Lake Sammamish has been determined to be
discrete as a result of its marked separation from other populations of
the same taxon as a consequence of physical, physiological, ecological,
or behavioral factors. There are no international governmental
boundaries within which differences in control of exploitation,
management of habitat, conservation status, or regulatory mechanisms
exist that are significant in light of Section 4(a)(1)(D) of the Act.
Accordingly, this discreteness criterion is not applicable to our
evaluation.
[[Page 61304]]
Lake Sammamish Kokanee Significance Analysis
Under the DPS policy, a determination as to whether the Lake
Sammamish kokanee population is a listable entity under the Act must
first consider its discreteness and significance with regard to the
remainder of the taxon, which includes all other sockeye salmon and
kokanee populations throughout the range of the biological species. If
a population segment is considered discrete under one or more of the
conditions listed in the Service's DPS policy, its biological and
ecological significance is considered in light of Congressional
guidance that the authority to list a DPS be used sparingly, while
encouraging the conservation of genetic diversity. In carrying out this
examination, we consider available scientific evidence of the
population segment's importance to the taxon to which it belongs. This
consideration may include, but is not limited to: (1) Its persistence
in an ecological setting unusual or unique for the taxon; (2) evidence
that its loss would result in a significant gap in the range of the
taxon; (3) evidence that it is the only surviving natural occurrence of
the taxon that may be more abundant elsewhere as an introduced
population outside of its historical range; or (4) evidence that the
discrete segment differs markedly from other populations of the species
in its genetic characteristics (FR 61 4721; February 7, 1996). A
population segment needs to satisfy only one of these criteria to be
considered significant. Furthermore, since the list of criteria is not
exhaustive, other criteria may be used if appropriate.
Significance Factor 1: Persistence of the discrete population
segment in an ecological setting unusual or unique for the taxon.
Significance Factor 1 Examination
(A) The Lake Washington/Lake Sammamish Basin is a large,
interconnected lake system containing two low-elevation mesotrophic
lakes (Edmondson 1979, pp. 234-235; Welch et al. 1977, p. 301).
Mesotrophic lakes are characterized by an intermediate concentration of
nutrients, moderate plant production, some organic sediment
accumulation, some loss of dissolved oxygen in the lower waters, and
moderate water clarity. Other lake systems that support or have
supported native sockeye populations (and by association their native
kokanee populations) are typically oligotrophic in nature (Mullan 1986,
pp. 71-73; Quinn 2005, p. 171). Oligotrophic lakes are characterized by
low concentrations of nutrients, limited plant production, little
accumulation of organic sediment on the bottom, an abundance of
dissolved oxygen, and good water clarity. Oligotrophic lakes are also
typically located at high elevations in interior areas where energetic
costs of anadromous migration are high (Wood 1995, pp. 202-203). In
addition to Lake Sammamish, the two other known exceptions are Lake
Ozette in Washington, which has been characterized as oligotrophic to
mesotrophic (or meso-oligotrophic) (Ritchie and Bourgeois 2010, p. 5),
and Lake Osoyoos, which straddles the Washington and B.C border in the
interior Columbia Basin, which has been characterized as a mesotrophic
system (Gustafson et al. 1997, p. 57).
Although we were unable to find comprehensive information on
limnology as it relates to lake systems occupied by O. nerka, within
the known and studied kokanee lakes, Lake Sammamish is the only
mesotrophic, easily accessible coastal lake, where energetic costs of
migration are minimal, that is known to support a native kokanee
population in the coterminous United States. Mesotrophic lakes
containing Oncorhynchus nerka populations appear to be rare in coastal
British Columbia (Shortreed 2007, p. vi; Woodruff 2010, pp. 47, 56). We
would also expect mesotrophic lakes that support kokanee to be rare or
absent within the northern portion of the species' range and at higher
elevations, since lakes with the lowest productivity are either at high
altitudes or high latitudes (Brylinsky and Mann 1973, p. 2). One
research biologist with the NOAAF Northwest Fishery Science Center,
commented that most sockeye salmon nursery lakes are typically strongly
nutrient limited (i.e., oligotrophic), and kokanee are not common in
easily accessible coastal lakes where the energetic costs of migration
are minimal (Gustafson 2009. pers comm.).
Although the presence of the petitioned entity in a mesotrophic
lake appears to be atypical, we do not have information on the
percentage or extent of mesotrophic lakes occupied by O. nerka
throughout the range of the taxon, and therefore cannot determine
whether this is actually an unusual or unique setting for O. nerka.
However, it is well-documented that the species occupies lakes with a
wide range of thermal regimes and other physical attributes (McPhail
2007, pp. 288, 295; Scott and Crossman 1973, p. 167; Mullen 1986 pp.
71-73; Quinn 2005, p. 171). These include coastal lakes in Washington
that stratify in summer with surface temperatures near 20 degrees
Celsius (C) (60 degrees Fahrenheit (F)), and remain mixed without
freezing in winter, to lakes in the interior and northern latitudes
that are ice-covered for at least half the year and have summer
temperatures barely above 10 degrees C (50 degrees F). Oncorhynchus
nerka occupies lakes that range in elevation from essentially sea level
to 2,000 m (6,550 ft), and in area from 1 to 2,600 square kilometers
(0.6 to 1,615 square miles), which includes coastal lakes from
Washington to Alaska and lakes in the interior of the Columbia, Fraser,
and Skeena river systems (Quinn 2005, p. 173). Anadromous O. nerka do
not occur naturally in Japan, although other populations are
distributed among several lakes. Native populations occur in Akan and
Chimikeppu Lakes (Kogura et al. 2011, pp. 2-3), and O. nerka also
occurs in Lake Toya, a large oligotrophic lake located in a caldera in
the central area of Hokkaido, in Northern Japan (Sakano et al., 1998,
p. 173). Based on our analysis, we are not aware of any scientific
evidence suggesting or demonstrating that the presence of an O. nerka
population in a mesotrophic lake is beyond the normal range of
variability that would be expected from a species that occupies the
diversity of habitat types where it has been documented, or that this
may represent an important trait from an adaptation/evolutionary
perspective.
In addition, NOAAF (1997, p. 20) states that Oncorhynchus nerka
exhibits the greatest diversity in selection of spawning habitat among
the Pacific salmon, and great variation in river entry timing and the
duration of holding in lakes prior to spawning. The species' adaptation
to a greater diversity of lake environments for adult spawning and
juvenile rearing has resulted in the evolution of complex timing for
incubation, fry emergence, spawning, and adult lake entry that often
involves intricate patterns of adult and juvenile migration and
orientation not seen in other Oncorhynchus species.
Conclusion: Oncorhynchus nerka exhibiting differing life-history
forms occupy a variety of ecosystems and watersheds in the north
Pacific from southern Kamchatka to Japan in the western Pacific, and
from Alaska to the Columbia River in North America (Page and Burr 1991,
p. 52; Taylor et al. 1996, pp. 402-403). We acknowledge Lake Sammamish
represents a complex ecological setting. However, the available
information indicates O. nerka occurs in a wide geographical range, and
habitat varies with respect to continental setting, latitude,
elevation,
[[Page 61305]]
and type(s) of waters used to support the species' physical and
biological needs. Given the available information on the diversity and
extent of ecological settings O. nerka occupies within the rest of its
range, the best scientific information available does not suggest that
Lake Sammamish represents a unique or unusual setting that may have
special significance relative to the taxon as a whole.
(B) The kokanee life form has historically been more abundant than
the sockeye life form in Lake Sammamish, although a larger number of
the sockeye life form would be expected because of the relatively easy
access to marine waters. Reports in the literature are equivocal as to
whether sockeye salmon were historically present in the Lake Sammamish
basin prior to the construction of the Lake Washington Ship Canal,
although kokanee were described as numerous (NOAA 1997, pp. 73-75).
Hendry (1995) in NOAA 1997 (p. 75), stated that limited runs of sockeye
salmon were probably present at the turn of the century in the Lake
Washington/Lake Sammamish drainage, and that it is ``certainly unlikely
that large populations were present.'' Young (2004, p. 1) stated the
Lake Sammamish/Lake Washington watershed supported only small
populations of sockeye, but large populations of kokanee in the period
from 1890 to 1920. In addition, the oral history of the Snoqualmie
Indian Tribe once characterized kokanee as being so abundant that
Tribal members could stand in the tributaries of Lake Sammamish and
scoop up the ``little red fish'' in their hands (Snoqualmie Indian
Tribe and Trout Unlimited 2008, p. 10).
As ancestral sockeye populations expanded to new river systems,
those that could not access the marine environment on a regular basis
evolved into the non anadromous kokanee form (Taylor et al. 1996, pp.
411-414). Kokanee populations are typically located at high elevations
in interior areas where energetic costs of anadromous migration are
high or where productive lakes can support both types (Wood 1995, pp.
202-203). In areas closer to and with easy access to marine waters,
sockeye populations typically dominate and kokanee are not common,
since the energetic costs of migration are minimal (Gustafson 2009,
pers comm.), and marine waters are much more productive. At higher
latitudes, productivity (and growing opportunities) is greater at sea
than in freshwater, as is evidenced by the more rapid growth of salmon
at sea than in streams and lakes (Quinn 2005, p. 6). Since Lake
Sammamish is located close to marine waters and is historically and
presently capable of accommodating anadromous migration, the
expectation would be that this should be a sockeye-dominated system.
The fact that kokanee appears to have been the more common Oncorhynchus
nerka life form in the Lake Washington/Lake Sammamish system
historically suggests there may have been at least some partial or
periodic barrier to anadromous sockeye in the past (Young et al. 2004,
p. 1).
Comparing Lake Sammamish to other nearby water bodies, Lake Whatcom
and Lake Ozette are geographically near marine waters and support
native kokanee populations; however, there are differences. Lake
Whatcom is oligotrophic (Matthews et al. 2002, p. 107), and has an
outlet that presents a long-standing natural barrier to anadromous
migration. Lake Ozette, although also near marine waters, is meso-
oligotrophic and dominated by sockeye.
Although the dominant presence of kokanee in a system where a
greater abundance of the sockeye life form would be expected is
notable, this does not necessarily lead to a conclusion that Lake
Sammamish represents a unique or unusual ecological setting. Quinn
(2005, pp. 10-11), states that all salmon are habitat generalists, and
populations tend to be very productive (i.e., when the population is
below its carrying capacity, each salmon produces many surviving
offspring). They spawn and rear in bodies of water ranging from tiny
creeks above waterfalls in the mountains, or streams discharging
directly into saltwater, to large rivers, and from small beaver ponds
and ephemeral wetlands to the largest lakes of the region. They are
found in a number of large rivers as well as in thousands of smaller
streams. Oncorhynchus nerka is the second most abundant Pacific salmon
species, having a primary spawning range from the Columbia River to the
Kuskokwim River in Alaska. In Asia they range from the Kuril Islands to
the area of the Anadyr River, but the heart of their distribution is
the Kamchatka Peninsula and tributaries of the Bering Sea. They spawn
in coastal systems and also ascent as far as 1,600 km (994 mi) to
Redfish Lake, Idaho (Quinn 2005, p. 14). We have no information on
whether there are any other lake systems that are predominately
occupied by the kokanee life form that would be expected to be
dominated by sockeye.
Conclusion: We have insufficient information to determine the
extent of waterbodies with relatively easy access to marine waters
where the kokanee form may be dominant over the anadromous form of O.
nerka across the range of the taxon. However, given the available
information on the diversity and extent of ecological settings of O.
nerka throughout the rest of its range, there is no information that
would suggest the apparent dominance of the kokanee life form over the
anadromous form in Lake Sammamish (at least since at least the late
19th century) supports a conclusion that Lake Sammamish constitutes a
unique or unusual setting that is significant to the taxon.
Significance Factor 2: Evidence that the loss of the population
would result in a significant gap in the range of the taxon.
Significance Factor 2 Examination
Lake Sammamish kokanee represent 1 of 11 known native kokanee
populations within the southern extent of their North American range,
and currently, we believe the best available information identifies 9
extant native kokanee populations that occur in the coterminous United
States (Lake Ozette, WA; Lake Sammamish, WA; Lake Whatcom, WA;
Chilliwack Lake, WA; Chain Lake, WA; Osoyoos Lake, WA; Stanley Lake,
ID; Redfish Lake, ID; and Alturas Lake, ID). The number of kokanee
populations in other areas within the range of the taxon is less well
known, but there are said to be well over 500 kokanee populations in
British Columbia (McPhail 2007, p. 295) alone. At one time there were
kokanee in Lake Washington as well as three different runs of kokanee
in Lake Sammamish. All other native kokanee that inhabited the Lake
Washington Basin are thought to be extinct, and the prevailing evidence
indicates that only the winter/late-run kokanee in the Lake Sammamish
Basin remain (Berge and Higgins 2003, p. 33; Jackson 2006, p. 1;
Warheit and Bowman 2008, p. 3).
Conclusion: The Lake Sammamish kokanee population is one of three
native kokanee populations (Lake Sammamish, Lake Whatcom, and
Chilliwack Lake) that evolved from sockeye populations within the Puget
Sound and the Strait of Georgia Basin regions. If Lake Sammamish
kokanee were to become extirpated, two other native kokanee populations
would persist from this evolutionary arm of the taxon, and there are
other native kokanee populations in the southern extent of their North
American range, although each of these populations expresses
differences in their geographic and biological characteristics. The
loss of Lake Sammamish kokanee, when considered in relation to
Oncorhynchus
[[Page 61306]]
nerka throughout the remainder of the species' range would mean the
loss of a very small geographic portion of the entire range of the
taxon, since this species occurs in watersheds in the north Pacific
from southern Kamchatka to Japan in the western Pacific, and from
Alaska to the Columbia River in North America (Page and Burr 1991, p.
52; Taylor et al. 1996, pp. 402-403). Due to the broad geographic range
of O. nerka, the wide diversity of habitats available to the species,
and the fact that this population is one of several O. nerka
populations within this portion of the range, we find the gap in the
range resulting from the loss of the Lake Sammamish population would
not be significant.
Significance Factor 3: Evidence that the population represents the
only surviving natural occurrence of a taxon that may be more abundant
elsewhere as an introduced population outside of its historical range.
Significance Factor 3 Examination
Since the taxon is widespread, there are 11 known populations of
native kokanee in the coterminous United States within the historic
range, and at least 500 kokanee populations in B.C., Lake Sammamish
kokanee do not represent the only surviving natural occurrence of the
taxon.
Significance Factor 4: Evidence that the population differs
markedly from other populations of the species in its genetic
characteristics.
Significance Factor 4 Examination
Relatively large genetic differences occur among the largest
sockeye salmon stocks in northwestern, coastal Canadian, and
southeastern parts of the species' range (Wood 1995, p. 197). Surveys
of genetic variation throughout the range of Oncorhynchus nerka provide
new insights about colonization patterns following the last glaciation
and the extent of reproductive isolation among spawning locations (Wood
1995, p. 196). Evidence from geological studies and the distribution of
freshwater fish assemblages strongly suggests that modern sockeye
salmon populations are derived primarily from a northern race that
survived glaciation in the Bering Sea area and a southern race that
survived south of the Cordilleran Ice Sheet in the Columbia River (Wood
et al. 2008, p. 208). This 4,000-feet thick (1,219-meters) ice sheet
expanded southward into Northern Washington, Idaho and Montana and had
three main lobes. The Puget lobe that scoured out the Puget Sound, the
Okanogan lobe that blocked the Columbia River at the site of the
present day Grand Coulee dam, and the Purcell lobe that blocked the
North Fork, Clark River near Cabinet Gorge on the Idaho-Montana border.
Postglacial (the time following a glacial period) adaptive evolution
occurred multiple times, resulting in native kokanee populations being
genetically more similar to their sympatric (i.e., occupying the same
geographic area without interbreeding) sockeye populations than kokanee
in other river systems (Taylor et al. 1996, pp. 401, 413-414).
Conclusion: Lake Sammamish kokanee may be 1 of only 11 remaining
native kokanee populations that evolved from the southern race of
sockeye and 1 of 3 that evolved in the Puget Sound/Georgia Basin
region. Given the presumed large number of kokanee populations across
the range of Oncorhynchus nerka (e.g., 500 kokanee populations in
British Columbia alone (McPhail 2007, p. 295)), based on the genetic
information currently available, the Lake Sammamish kokanee population
does not differ markedly from other O. nerka populations with respect
to the variability beyond the species' norm of distribution, such that
they should be considered biologically or ecologically significant
based on genetic characteristics. Although each O. nerka population
likely expresses some degree of genetic distinctiveness because of
differing responses to evolutionary pressures, Lake Sammamish kokanee
do not demonstrate any unique or unusual genetic distinctiveness beyond
that which would be expected between other populations throughout the
range of the taxon. When measuring this evidence against the DPS
standard, we are required to look for evidence of marked
differentiation of this Lake Sammamish kokanee population segment
compared to other populations of Oncorhynchus nerka throughout the
range of the taxon. More importantly, scientific information to
indicate that the genetic divergence observed in the Lake Sammamish
kokanee population segment confers a fitness advantage or otherwise
contributes to the biological or ecological importance of this
population, in relation to the taxon as a whole, is lacking. With the
additional consideration that the authority to list DPSs be used
``sparingly,'' we conclude this population segment of O. nerka does not
meet the significance element of this factor.
Other Potential Significance Factors Examined
(A) Disease resistance: Infectious hematopoietic necrosis (IHN) is
a serious viral disease of salmonid fish, which was first reported at
fish hatcheries in Oregon and Washington in the 1950s. The causative
virus now exists in many wild and farmed salmonid stocks in the Pacific
Northwest region of North America, and has spread to Europe and some
Asian countries. IHN virus (IHN) affects rainbow/steelhead trout (O.
mykiss), cutthroat trout (Salmo clarki), brown trout (Salmo trutta),
Atlantic salmon (Salmo salar), and Pacific salmon including chinook (O.
tshawytscha), sockeye/kokanee (O. nerka), chum (O. keta), masou/yamame
(O. masou), amago (O. rhodurus), and coho (O. kisutch) (Iowa State
University, 2007, p. 1). Over 40 million kokanee were introduced into
the Sammamish basin from the Lake Whatcom Hatchery between 1940 and
1978 (Young et al. 2004, p. 65); however, these introduced stocks have
not been successful. The Lake Sammamish kokanee population remains
extant, whereas transplanted stocks were unable to persist (Young et
al. 2004, p. 1). The reasons are unknown, and there has been some
speculation that this could be related to a disease resistance function
to IHN; however, this theory has not been confirmed. This speculation
is based on Young et al. 2004 (p. 3), who stated, ``We note that the
Lake Washington/Lake Sammamish Basin is an IHN positive environment and
that Lake Whatcom is IHN free. We speculate that IHN vulnerability
might explain the apparent lack of success of the Lake Whatcom kokanee
introductions, however, confirmation or refutation would require
further study.'' However, while these authors speculated as to the
vulnerability of Lake Whatcom kokanee to IHN, it does not follow that
Lake Sammamish kokanee are, therefore, resistant to, or tolerant of,
the disease. We were also unable to find any additional studies
regarding disease resistance or disease tolerance of the Lake Sammamish
kokanee, so this idea remains merely speculative at this time.
Even assuming that Lake Sammamish kokanee may be resistant to IHN,
this does not mean disease resistance is unique to kokanee in the Lake
Washington/Lake Sammamish system. We were unable to find any
information on IHN presence in other lakes within the range of
Oncorhynchus nerka, so were unable to determine whether a presumed
resistance or tolerance to IHN (as evidenced by presence of a
population of O. nerka in IHN-positive lakes) is unusual such that a
population evidencing this disease resistance or tolerance would be
significant to the taxon as a whole.
[[Page 61307]]
Conclusion: Although disease resistance or tolerance may be
important to the long-term viability of Oncorhynchus nerka at some
scale, the relevant question for this finding is whether the Lake
Sammamish kokanee population is significant to the taxon as a whole
(i.e., all O. nerka populations and life history forms throughout the
range of the species). Given that there is no evidence indicating that
the Lake Sammamish kokanee are disease resistant or disease tolerant,
and that we were unable to find any information on IHN presence in
other lakes containing O. nerka populations in order to determine
whether Lake Sammamish is atypical, we conclude that the hypothesized
disease resistance or tolerance of the Lake Sammamish kokanee
population does not meet the significance element of the DPS policy.
(B) Multiple run spawning timings: Multiple run timings allow
kokanee and other salmonid populations the ability to exploit a range
of available habitats and reduce risks to extirpation (e.g., stochastic
events, predation, variable climate) by diversifying spawning
distribution over space and time. The Lake Sammamish/Lake Washington
kokanee population historically had at least three distinct run timings
expressed in different locations within the basin. The expression of
multiple-run timings within populations appears to be rare across the
range of kokanee, especially among tributaries (Wood 2009, pers comm.),
although there are at least a few other kokanee populations that are
known to exhibit this trait (Shepard 1999). In addition, the literature
indicates that other kokanee populations have run timings that occur
during similar times of the year as do the run timings of the Lake
Sammamish kokanee (Scott and Crossman 1973, p. 167). With regard to the
taxon-wide examination, NOAAF (1997, p. 20) states that Oncorhynchus
nerka exhibits the greatest diversity in selection of spawning habitat
among the Pacific salmon, and great variation in river entry timing and
the duration of holding in lakes prior to spawning. Bimodal run timing
(two spawning runs in a single season) for O. nerka populations have
been demonstrated in the Russian River in Alaska (Nelson 1979, p. 3),
the Klukshu River, Yukon Territory (Fillatre et al. 2003, p. 1), and
Karluk Lake on Kodiak Island, Alaska (Schmidt et al. 1998, p. 744).
Conclusion: Under the DPS policy, we are required to evaluate the
Lake Sammamish kokanee population segment's significance relative to
the taxon as a whole. Therefore, given the available information on the
number of O. nerka populations across the range of the species (see
sockeye and kokanee abundance trends above), and the presence of
bimodal run timing in other populations, we conclude the presence of
multiple run timings in Lake Sammamish is not significant to the taxon.
DPS Conclusion
On the basis of the best available information, we conclude that
the Lake Sammamish kokanee population segment is discrete due to marked
separation as a consequence of physical, ecological, physiological, or
behavioral factors according to the 1996 DPS policy. However, on the
basis of the four significance elements in the 1996 DPS policy, we
conclude this discrete population segment is not significant to the
remainder of the taxon and therefore, does not qualify as a DPS under
our 1996 DPS policy. As such, we find the Lake Sammamish kokanee
population is not a listable entity under the Act.
Finding
In making this finding, we considered information provided by the
petitioners, as well as other information available to us concerning
the Lake Sammamish kokanee population. We have carefully assessed the
best scientific and commercial information available regarding the
status and threats to the Lake Sammamish kokanee population. We
reviewed the petition and unpublished scientific and commercial
information. We also consulted with Federal and State land managers,
and scientists having expertise with Oncorhynchus nerka. This 12-month
finding reflects and incorporates information received from the public
following our 90-day finding or obtained through consultation or
literature research.
On the basis of that review, we have determined that the Lake
Sammamish kokanee does not meet the elements of our 1996 DPS policy as
being a valid DPS. Consequently, we find the Lake Sammamish kokanee
population is not a listable entity under the Act, and that listing is
not warranted.
References
A complete list of all references cited is available at http://www.regulations.gov, or upon request from the Washington Fish and
Wildlife Office (see ADDRESSES).
Author
The primary authors of this document are staff of Region 1, Pacific
Region, U.S. Fish and Wildlife Service.
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Dated: September 23, 2011.
Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2011-25595 Filed 10-3-11; 8:45 am]
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