[Federal Register: August 25, 2010 (Volume 75, Number 164)]
[Rules and Regulations]
[Page 52272-52282]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25au10-17]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R1-ES-2008-0084; [92220-1113-0000-C6]
RIN 1018-AW16
Endangered and Threatened Wildlife and Plants; Removal of the
Utah (Desert) Valvata Snail From the Federal List of Endangered and
Threatened Wildlife
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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SUMMARY: Under the authority of the Endangered Species Act of 1973, as
amended (Act), we, the U.S. Fish and Wildlife Service (Service), are
removing the Utah (desert) valvata snail (Valvata utahensis) from the
Federal List of Endangered and Threatened Wildlife (List). Based on a
thorough review of the best available scientific and commercial data,
we determined that the Utah valvata snail is more widespread and occurs
in a greater variety of habitats in the Snake River than known at the
time of listing in 1992. We now know the Utah valvata snail is not
limited to areas of cold-water springs or spring outflows; rather, it
persists in a variety of aquatic habitats, including cold-water
springs, spring creeks and tributaries, the mainstem Snake River and
associated tributary stream habitats, and reservoirs influenced by dam
operations. Given our current understanding of the species' habitat
requirements and threats, the species does not meet the definition of
an endangered or threatened species under the Act. Therefore, we are
removing the Utah valvata snail from the List, thereby removing all
protections provided by the Act.
DATES: This effective date of this rule is September 24, 2010.
ADDRESSES: This final rule is available on the Internet at http://
www.regulations.gov and at http://www.fws.gov/idaho. Comments and
materials received, including supporting documentation used in
preparing this rule, will be available for public inspection, by
appointment, during normal business hours at the U.S. Fish and Wildlife
Service, Idaho Fish and Wildlife Office, 1387 S. Vinnell Way, Room 368,
Boise, ID 83709; by telephone.
FOR FURTHER INFORMATION CONTACT: Brian Kelly, State Supervisor, at the
above address; by telephone 208-378-5243; or by fax at 208-378-5262 e-
mail at: fw1srbocomment@fws.gov. 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
The Utah valvata snail (Valvata utahensis) was first recognized as
a species in 1902, based on specimens collected from Utah Lake and Bear
Lake, Utah (Walker 1902, p. 125). Its common name has since been
changed by the American Fisheries Society to the ``desert valvata'' in
the benchmark text for aquatic invertebrate nomenclature, Common and
Scientific Names of Aquatic Invertebrates from the United States and
Canada (Turgeon et al. 1998, p. 109), presumably due to the fact that
it is no longer known to occur in Utah. However, because the species is
currently listed in the Code of Federal Regulations as the Utah valvata
snail, Valvata utahensis will be referred to as the Utah valvata snail
throughout this final rule.
Range
The Utah valvata snail, or at least its closely related ancestors,
has been described as ranging widely across the western United States
and Canada as far back as the Jurassic Period, 199.6 0.6
to 145.5 4 million years ago (Taylor 1985a, p. 268).
Fossils of the Utah valvata snail are known from Utah to California
(Taylor 1985a, pp. 286-287). The Utah valvata snail was likely present
in the ancestral Snake River as it flowed south from Idaho, through
Nevada, and into northeastern California (Taylor 1985a, p. 303). The
Snake River's course changed to join the Columbia River Basin
approximately 2 million years ago (Hershler and Liu 2004, pp. 927-928).
[[Page 52273]]
At the time of listing in 1992 (57 FR 59244, December 14, 1992), we
reported the range of the Utah valvata snail as being limited to a few
springs and mainstem Snake River sites in the Hagerman Valley, Idaho
(River Mile (RM) 585), a few sites above and below Minidoka Dam (RM
675), and immediately downstream of American Falls Dam (RM 709).
New data collected since the time of listing indicate that the Utah
valvata snail is discontinuously distributed in at least 255 miles (410
kilometers (km)) of the Snake River and some associated tributary
streams, an increase of nearly 122 river miles (196 km) from the known
range at the time of listing. Their current range in the Snake River
extends from RM 585 near the Thousand Springs Preserve (Bean in litt.
2005), upstream to the confluence of the Henry's Fork with the Snake
River (RM 837; Fields 2005, p. 11). Colonies of the Utah valvata snail
have been found in the Snake River near the towns of Firth (RM 777.5),
Shelley (RM 784.6), Payne (RM 802.6), and Roberts (RM 815), and in the
Henry's Fork approximately 9.3 miles (15 km) upstream from its
confluence with the Snake River (at Snake RM 832.3) (Gustafson in litt.
2003). Based on limited mollusk surveys, the species has not been found
upstream from the described location on the Henry's Fork or in the
South Fork of the Snake River. Tributary streams to the Snake River
where Utah valvata snails have been collected include Box Canyon Creek
(RM 588) (Taylor 1985b, pp. 9-10), and one location in the Big Wood
River (Wood River Mile (WRM) 35) (USBR 2003, p. 22).
Habitat Use
At the time of listing in 1992, the best available data indicated
that Utah valvata snails ``characteristically require cold, fast water,
or lotic habitats * * * in deep pools adjacent to rapids or in
perennial flowing waters associated with large spring complexes'' (57
FR 59244, December 14, 1992). In numerous field studies conducted since
then, the species has been collected at a wide range of water depths,
ranging from less than 3.2 feet (1 meter) (Stephenson and Bean 2003,
pp. 98-99) to depths greater than 45 feet (14 meters) (USBR 2003, p.
20), and at temperatures between 37.4 and 75.2 degrees Fahrenheit (F)
(4 to 24 degrees Celsius (C)) (Lysne in litt. 2007; Gregg in litt.
2006).
Work conducted by the Idaho Department of Fish and Game (IDFG) in
the upper Snake River demonstrated that Utah valvata snail presence was
positively correlated with water depth (up to 18.37 feet (5.6 meters))
and temperature (up to 63 degrees F (17.2 degrees C)) (Fields 2005, pp.
8-9), and Utah valvata snail density was positively correlated with
macrophyte (a water plant large enough to be observed with the unaided
eye) coverage, water depth, and temperature (Fields 2006, p. 6).
Similarly, Hinson (2006, pp. 28-29) analyzed available data from
several studies conducted by the U.S. Bureau of Reclamation (USBR)
(2001-2004), Idaho Power Company (IPC) (1995-2002), IDFG, Idaho
Transportation Department (2003-2004) and others, and demonstrated a
positive relationship between Utah valvata snail presence and
macrophytes, water depth, and fine substrates. One study reported Utah
valvata snails in organically enriched fine sediments with a heavy
macrophyte community, downstream of an aquaculture facility (RM 588)
(Hinson 2006, pp. 31-32).
Survey data and information reported since the time of listing
demonstrate that the Utah valvata snail is able to live in reservoirs,
which were previously thought to be unsuitable for the species (Frest
and Johannes 1992, pp. 13-14; USBR 2002, pp. 8-9; Fields 2005, p. 16;
Hinson 2006, pp. 23-33). We now know the Utah valvata snail persists in
a variety of aquatic habitats, including cold-water springs, spring
creeks and tributaries, the mainstem Snake River and associated
tributary stream habitats, and reservoirs.
Alterations of the Snake River, including the construction of dams
and reservoir habitats, have changed fluvial processes resulting in the
reduced likelihood of naturally high river flows or rapid changes in
flows, and the retention of fine sediments (U.S. Environmental
Protection Agency (USEPA) 2002, pp. 4.30-4.31), which may also increase
potential habitat for the species (e.g., Lake Walcott and American
Falls Reservoirs; however, see Summary of Factors Affecting the Species
below for a discussion of the effects of rapidly drawing down
reservoirs). Utah valvata snail surveys conducted downstream from
American Falls Dam (RM 714.1) to Minidoka Dam (RM 674.5), from 1997 and
2001-2007, consistently found Utah valvata snails on fine sediments
within this 39-mile (62.9 km) river/reservoir reach of the Snake River
(USBR 1997, p. 4; USBR 2003, p. 8; USBR 2004, p. 5; USBR 2005, p. 6;
USBR 2007, pp. 9-11; USFWS 2005, p. 119). Surveys conducted downstream
of Minidoka Dam (RM 674.5) to Lower Salmon Falls Dam (RM 573.0) have
also documented Utah valvata snails in that reach, including one record
from the tailrace area of Minidoka Dam (the downstream part of a dam
where the impounded water reenters the river) in 2001 (USFWS 2005, p.
120).
In summary, based on available data, the Utah valvata snail is not
as specialized in its habitat needs as we thought at the time of
listing. In the Snake River, the species inhabits a diversity of
aquatic habitats throughout its 255-mile (410 km) range, including
cold-water springs, spring creeks and tributaries, mainstem and free-
flowing waters, reservoirs, and impounded reaches. The species occurs
on a variety of substrate types including both fine sediments and more
coarse substrates in areas both with and without macrophytes. It has
been collected at water depths ranging from less than 3.2 feet (1
meter) to greater than 45 feet (14 meters), and at water temperatures
ranging from 37.4 to 75.2 degrees F (3 to 24 degrees C).
Population Density
Like many short-lived and highly fecund invertebrates, the density
of Utah valvata snails at occupied sites can vary greatly. For example,
at one cold-water spring site at the Thousand Springs Preserve, Utah
valvata snail density in 2003 ranged between 0 and 1,724 snails per
square meter (/m\2\), with an average of 197 snails/m\2\ (Stephenson et
al. 2004, p. 23). In the mainstem Snake River between American Falls
Reservoir and Minidoka Dam in 2002, Utah valvata snail densities
averaged 91 snails/m\2\ (ranging from 0 to 1,188 snails/m\2\), and in
American Falls Reservoir densities averaged 50 snails/m\2\ (range
unavailable) (USBR 2003, p. 20). In 2008 and 2009, monitoring efforts
were carried out at sites first monitored by the USBR in the late 1990s
and early 2000s below American Falls Reservoir, which is a free-flowing
riverine environment (Gates in litt. 2009). Monitoring results indicate
these specific colonies have decreased in density and proportional
occurrence compared to results from the late 1990s and early 2000s,
with the greatest densities found in 2009 ranging from 4 to 24 snails/
m\2\ and presence ranging from 5 to 9 percent (Gates in litt. 2009).
However, 2009 monitoring sites do not represent a comprehensive survey
of the area below American Falls Reservoir as only two of the four
largest colonies sampled in 2008 were sampled in 2009 (Gates in litt.
2009). Above American Falls Reservoir in the mainstem Snake River, Utah
valvata snail densities sampled in 2004 at six sites averaged 117
snails/m\2\ (ranging from 0 to 1,716 snails/m\2\) (Fields 2006, pp. 12-
13).
[[Page 52274]]
Within occupied reservoirs, the proportional occurrence of snails
is relatively high. For all field studies and surveys, lower Lake
Walcott Reservoir had the highest proportional occurrence (USBR 2002,
p. 5; USBR 2003, p. 6). For sample years 2001 to 2006, the relative
proportion of samples containing Utah valvata snails ranged from 40 (in
2004) to 62 (in 2002) percent of samples collected. Similarly, American
Falls reservoir samples contained a high proportion of Utah valvata
snails, with the species detected in 21 (in 2001) to 33 (in 2003)
percent of samples. Such high proportional occurrence in reservoirs
over multiple years is additional evidence that Utah valvata snails are
using reservoir habitats and are not restricted to cold-water springs
or their outflows.
Previous Federal Actions
We listed the Utah valvata snail as endangered on December 14, 1992
(57 FR 59244). Based on the best available data at that time we
determined that the Utah valvata snail was threatened by proposed
construction of new hydropower dams, the operation of existing
hydropower dams, degraded water quality, water diversions, the
introduced New Zealand mudsnail (Potamopyrgus antipodarum), and the
lack of existing regulatory protections (57 FR 59244). In 1995, we
completed the Snake River Aquatic Species Recovery Plan (Plan), which
included the Utah valvata snail. We have not designated critical
habitat for this species.
On April 11, 2006, we initiated a 5-year review of the species'
status (71 FR 18345) in accordance with section 4(c)(2) of the
Endangered Species Act of 1973, as amended (Act; 16 U.S.C. 1531 et
seq.). On December 26, 2006, the Service received a petition from the
Governor of Idaho and attorneys from several irrigation districts and
canal districts requesting that we remove the Utah valvata snail from
the List. On June 6, 2007, the Service published a Federal Register
notice announcing that the petition presented substantial scientific
information indicating that removing the Utah valvata snail from the
List may be warranted, and initiating a status review (72 FR 31264). As
part of our best available scientific and commercial data analysis, we
conducted a 30-day peer review on a draft status-review document, which
was completed in September 2007 (USFWS in litt. 2007).
On July 16, 2009, we published a warranted 12-month finding on the
delisting petition and a proposed rule to remove the Utah valvata snail
from the Federal List of Endangered and Threatened Wildlife (74 FR
34539). We solicited data and comments from the public on the proposed
rule. The comment period opened on July 16, 2009, and closed on
September 14, 2009. A summary of the comments we received and our
responses are provided below.
Summary of Comments and Responses
In accordance with our policy on peer review, published on July 1,
1994 (59 FR 34270), we solicited scientific peer review from four
appropriate and independent experts following publication of the
proposed rule. Reviewers were asked to review the proposed rule to help
ensure our use of the best available scientific and commercial data,
and to maximize the quality, objectivity, thoroughness, and utility of
the information upon which the final rule is based. One of the peer
reviewers submitted comments which we summarize and respond to below.
Peer Review Comments and Responses
(1) Comment: New monitoring data collected in the Vista/Neeley
section of the Snake River below American Falls Reservoir (RM 713; a
free flowing riverine environment) from 2008 and 2009 indicate lower
Utah valvata snail densities than were observed during surveys in the
late 1990s and early 2000s. These data, along with other preliminary
sampling results provided, suggest that Utah valvata snail populations
can experience large fluctuations in population size within and among
years.
Our Response: We thank the peer reviewer for the additional
monitoring data, which we have incorporated into this final rule.
While the Utah valvata snail population appears to have declined
between 2002 and 2009 in the Vista/Neeley section (RM 713) of the Snake
River, it should be noted that different collection methods and sample
sizes used for data collection limit our ability to precisely quantify
site-specific Utah valvata snail population declines. Also, the data
reported are from a small portion (within 1.92 miles (3.2 km)) (USBR
2003, p. 4) of the 255-river-mile (410 km) range of the Utah valvata
snail in the Snake River and tributary streams. Lastly, the 2009
monitoring sites do not represent a comprehensive survey of the reach
below American Falls dam because they were based on only two of the
four largest colonies that were sampled in 2008.
Compared to vertebrate species, most invertebrates have short
generation times, small body size, and rapid rates of population
increase and decline. For these reasons, invertebrate populations
frequently undergo large fluctuations in size and may vary greatly
between years due to environmental parameters and other factors
affecting habitat (Ricklefs 1979, pp. 509-510; Murphy et al. 1990, p.
41).
In general, consistent, long-term monitoring of population
abundance and persistence throughout the range of the Utah valvata
snail is lacking. This limits our ability to calculate reliable
estimates of population trends. In the case of Utah valvata snails,
although there appears to be large interannual variation in population
numbers at the few sites for which we have monitoring data, such as in
the Vista/Neeley section of the Snake River, this is not necessarily an
indication that the species' status has degraded or that the species is
undergoing a long-term population decline.
(2) Comment: The peer reviewer stated that the greatest threat to
the Utah valvata snail is from annual dewatering of the Snake River
below the mainstem dams. Annual water drawdowns expose hundreds of
meters of littoral zone habitat in the Vista/Neeley and Coldwater
sections of the Snake River within a period of days.
Our Response: In making our delisting determination, we evaluated
several threat factors, including the operation of existing hydropower
dams. Within the Vista/Neeley section below American Falls reservoir,
Utah valvata snails are able to re-colonize most submerged zones during
summer high flows (USFWS 2005, p. 127). Although up to 54 percent of
the Utah valvata population in the Neeley reach may be subject to
desiccation from annual water withholdings upstream for storage,
existing operations by the Bureau of Reclamation that provide minimum
flows (350 cubic feet per second (cfs)) below American Falls Dam (USFWS
2005, p. 25) are likely to provide for a viable population there (USFWS
2005, pp. 127-128). While annual drawdowns are likely to negatively
affect Utah valvata snail populations in certain years, the best
available data indicate that these drawdowns are not likely to lead to
significant, long-term population declines (USFWS 2005, pp. 127-128).
A complete review and evaluation of the threats affecting the Utah
valvata snail, including a discussion of our rationale in assessing
those threats, is presented in the Summary of Factors Affecting the
Species section of this rule.
(3) Comment: The peer reviewer stated that 10 years of data
indicate the continued coexistence of the Utah
[[Page 52275]]
valvata snail and New Zealand mudsnails in the Vista/Neeley section of
the Snake River (RM 713), which implies that the New Zealand mudsnail
is not considered a threat to the persistence of the Utah valvata
snail. However, the peer reviewer recommends future population
monitoring at these sites.
Our Response: The Service would like to thank the peer reviewer for
the data and comments. A complete review and evaluation of the threat
of the New Zealand mudsnail, including a discussion of our rationale in
assessing those threats, is presented in the Summary of Factors
Affecting the Species section of this rule.
Public Comments and Responses
During the 60-day comment period on the proposed rule, we received
four public comments, in addition to the peer review comment. Public
comments that provided new substantive information were incorporated
into this final rule, and are addressed below.
(4) Comment: The State of Idaho's Office of Species Conservation,
along with three canal companies and four irrigation districts,
supports the proposal to delist the Utah valvata snail based on new
information regarding its distribution and habitat requirements. There
are several management plans and measures, not identified in the
proposed rule, which will likely benefit the Utah valvata snail by
increasing Snake River flows including: The Nez Perce Water Rights
Agreement, the Bell Rapids Mutual Irrigation Company Water Rights
Purchase, and recent aquifer management planning projects within the
range of the Utah valvata snail. In addition, information was provided
that the 2004 Idaho Power Company Integrated Resource Plan does not
identify new hydropower projects within the range of the Utah valvata
snail.
Our Response: We thank the State of Idaho and others for the
additional information. We have incorporated the relevant information
into the Summary of Factors Affecting the Species section below.
(5) Comment: Several commenters provided new data and information
regarding the ecology and threat factors affecting the Utah valvata
snail. One commenter said that competition between the Utah valvata
snail and the nonnative, invasive New Zealand mudsnail may be a more
significant threat than we described, and therefore we should further
consider the effects of the New Zealand mudsnail and other invasive
species on the Utah valvata snail before removing it from the Federal
List of Endangered and Threatened Wildlife. In addition, this commenter
stated that the effects of climate change represent a new threat to the
Utah valvata snail and its habitat and should be addressed and analyzed
in the final rule.
Our Response: We thank the commenters who provided new information
and data for our consideration in making this final determination. We
have evaluated the available scientific and commercial data regarding
the Utah valvata contained in reports, biological assessments and
opinions, published journal articles, and other documents.
Our knowledge and understanding of the habitat needs of the Utah
valvata snail has changed substantially since the species was listed in
1992. Survey data collected since 1992 indicate that the geographic
range of the species in the Snake River is approximately 122 river
miles (196 km) larger than known at the time of listing, that it occurs
in a variety of substrate types (e.g., fines to cobble size) and flows,
and that it tolerates a range of water-quality parameters.
Surveys have shown the New Zealand mudsnail frequently co-occurs
with the Utah valvata snail and may compete for habitat or food.
Although the New Zealand mudsnail has been reported at extremely high
densities in the middle Snake River (Richards et al. 2001, p. 375), and
at moderate-to-high densities at five sites in tributaries to the Snake
River and the Snake River above American Falls Reservoir, there is no
evidence that after 20 years of co-occurrence the New Zealand mudsnail
has caused local extirpations of the Utah valvata snail.
Regarding climate change, there is compelling evidence that we are
living in a time of rapid, worldwide climate change. For example, 11 of
the 12 years from 1995-2006 rank among the 12 warmest years since 1850
(Independent Scientific Advisory Board (ISAB) 2007, p. iii). In the
Pacific Northwest, regionally averaged temperatures have risen 1.5
degrees F (0.8 degrees C) over the last century, and are projected to
increase by another 3 to 10 degrees F (1.5 to 5.5 degrees C) over the
next 100 years (Mote et al. 2003, p. 54; Karl et al. 2009, p. 135).
While the specific effects of global climate change on the Utah valvata
snail are unclear, aquatic species and their habitats may be
particularly vulnerable to changes in temperatures and precipitation
patterns. Nevertheless, our current understanding of the Utah valvata
snail is that it occurs in a variety of substrate types (e.g., fines to
cobble size), flows, and depths, and tolerates a range of water-quality
parameters, including elevated water temperatures.
Our updated evaluation of the threat factors, including climate
change, to the Utah valvata snail is presented in the Summary of
Factors Affecting the Species section of this final rule.
(6) Comment: One commenter stated that populations believed to be
Utah valvata snails may in fact be Valvata humeralis, and therefore
recommended that we positively identify all Utah valvata snail
populations, through genetic analysis, before removing them from the
Federal List of Endangered and Threatened Wildlife.
Our Response: Studies and surveys have documented the Valvata
humeralis snail often co-occurs with the Utah valvata snail. Although
these two species possess many similar morphological characteristics,
they can be distinguished through variations in shell morphology. The
Utah valvata possesses a taller shell spire and more prominent carinae
than the Valvata humeralis (Burch 1989, pp. 82-83; Walker 1902, pp.
121-125). Miller et al. (2006b, pp. 3-4) confirmed through genetic
analysis that the Utah valvata snail and Valvata humeralis are distinct
species and demonstrated that the species can be effectively
distinguished using morphological characteristics (i.e., the
morphological data aligned with the genetic data).
The Service, along with other agencies and researchers, use the
difference in shell morphology as the primary method to differentiate
between these two species. While we acknowledge, given morphological
similarities, there is potential to confuse individuals of these two
species where they co-occur (Miller et al. 2006b, p. 1), genetic data
confirm Utah valvata snail occurrence at multiple sites within the
geographic range described at the beginning of this document (Miller et
al. 2006b, entire). Therefore, the Service believes that additional
genetic testing of all Utah valvata snail populations for
identification purposes is unnecessary.
Summary of Factors Affecting the Species
Section 4 of the Act (16 U.S.C. 1533) and implementing regulations
(50 CFR part 424) set forth procedures for adding species to, removing
species from, or reclassifying species on the Federal List of
Endangered and Threatened Wildlife (List).
Under section 4 of the Act, a species may be determined to be
endangered or threatened on the basis of any of the following five
factors: (A) Present or threatened destruction, modification, or
curtailment of habitat or range; (B)
[[Page 52276]]
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence. We must consider these same five
factors in delisting a species. We may delist a species according to 50
CFR 424.11(d) if the best available scientific and commercial data
indicate that the species is neither endangered nor threatened for the
following reasons: (1) The species is extinct; (2) the species has
recovered and is no longer endangered or threatened; or (3) the
original scientific data used at the time the species was classified
were in error.
A species is ``endangered'' for purposes of the Act if it is in
danger of extinction throughout all or a significant portion of its
range and is ``threatened'' if it is likely to become endangered within
the foreseeable future throughout all or a significant portion of its
range.
Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of the Species' Habitat or Range
Construction of New Hydropower Dams
In our 1992 final rule listing the Utah valvata snail as an
endangered species, we stated: ``Six proposed hydroelectric projects,
including two high dam facilities, would alter free flowing river
reaches within the existing range of [the Utah valvata snail]. Dam
construction threatens the [Utah valvata snail] through direct habitat
modification and moderates the Snake River's ability to assimilate
point and non-point pollution. Further hydroelectric development along
the Snake River would inundate existing mollusc habitats through
impoundment, reduce critical shallow, littoral shoreline habitats in
tailwater areas due to operating water fluctuations, elevate water
temperatures, reduce dissolved oxygen levels in impounded sediments,
and further fragment remaining mainstem populations or colonies of
these snails'' (57 FR 59251).
Since the time of listing, proposed hydroelectric projects
discussed in the 1992 final rule are no longer moving forward. The A.J.
Wiley project and Dike Hydro Partners preliminary permits have lapsed;
the Kanaka Rapids, Empire Rapids, and Boulder Rapids permits were
denied by the Federal Energy Regulatory Commission (FERC) in 1995;
there was a notice of surrender of the preliminary permit for the River
Side Project in 2002; and two other proposed projects, the Eagle Rock
and Star Falls Hydroelectric Projects, were denied preliminary permits
by the FERC. In 2003, a notice was provided of surrender of preliminary
permit for the Auger Falls Project. Information provided by the State
of Idaho indicates that all proposals and preliminary permits for the
construction of new dams along the mid-Snake River have either lapsed
or been denied by the FERC (Caswell in litt. 2006). In addition, the
2006 IPC Integrated Resource Plan does not identify any new, large
hydropower projects within the Snake River (IPC 2006, p. 57). Lastly,
recent studies have shown that the Utah valvata snail is not as limited
in its geographic range or habitat needs as we had thought at the time
of listing (see Background section above).
Operation of Existing Hydropower Dams
In the 1992 final rule, we discussed peak-loading, the practice of
artificially raising and lowering river levels to meet short-term
electrical needs by local run-of-the-river hydroelectric projects, as a
threat to the Utah valvata snail. We also stated, as was our
understanding at the time, that the Utah valvata snail ``cannot
tolerate true impoundment or reservoir conditions'' (57 FR 59248).
Studies conducted since the time of listing have shown the Utah valvata
snail is able to persist in reservoirs and in areas downstream of peak-
loading dams, contrary to our understanding of the species at the time
of listing (USFWS 2005, pp. 105, 127-128; 57 FR 59244, 59245). For
example, Lake Walcott (RM 702.5 to 673.5; upstream of Minidoka Dam)
appears to contain the largest population of Utah valvata snails in the
Snake River system (USFWS 2005, pp. 111-112). This is likely due to
relatively good water quality in the reservoir compared to downstream
sections of the Snake River near Hagerman where water quality is
influenced by agricultural, municipal, and aquaculture flows into the
river. In lower Lake Walcott, there is a large area of suitable Utah
valvata snail habitat that remains submerged despite annual drawdowns
during the irrigation season (the reservoir fluctuates up to 5 feet
(1.5 meters) annually, thereby limiting the number of snails affected
by dewatering and desiccation). Further, surveys conducted in the
mainstem Snake River in 1997, 1998, and 2001 from American Falls Dam
(RM 714.1) to Lake Walcott (RM 702.5) indicate a fairly large and
viable population of Utah valvata snails even though shoreline habitats
in this stretch undergo annual dewatering (USFWS 2005, p. 119). In
American Falls reservoir, dam operations and fluctuating flows have
been estimated to kill between 5 and 40 percent of the Utah valvata
snails through dewatering and desiccation of their habitat in most
years. Nevertheless, Utah valvata snails continue to persist in both
American Falls and Lake Walcott reservoirs with relatively high
proportional occurrence (USFWS 2005, p. 119).
Degraded Water Quality
In the 1992 final listing rule, we stated: ``The quality of water
in [snail] habitats has a direct effect on the species [sic] survival.
The [Utah valvata snail] require[s] cold, well-oxygenated unpolluted
water for survival. Any factor that leads to deterioration in water
quality would likely extirpate [the Utah valvata snail]'' (57 FR
59252). As described above in the Species Information section, our
understanding of the species' habitat requirements has changed
substantially since 1992. Furthermore, new information has become
available indicating (a) improvements to Snake River water quality
where the species lives, and (b) that Utah valvata snails inhabit and
persist in reaches of the Snake River rich in nutrients (e.g., nitrogen
and phosphorus).
Factors that are known to degrade water quality in the Snake River
include reduced water flow, warming due to impoundments, and increases
in the concentration of nutrients, sediment, and pollutants reaching
the river from agricultural and aquaculture inputs (USFWS 2005, p.
106). In the 1990s and early 2000s, several water-quality assessments
were completed for the Snake River by the USEPA, USBR, U.S. Geological
Survey (USGS), and IPC. All of these assessments generally demonstrate
that water quality in the Snake River of southern Idaho meets Idaho's
water-quality criteria for the protection of aquatic life for some
months of the year, but may be poor in reservoirs or during summer when
temperatures are high and flows are low (Clark et al. 1998, pp. 20-21,
24-27; Clark et al. 2004, pp. 38-40; Clark and Ott 1996, p. 553; Clark
1997, pp. 1-2, 19; Meitl 2002, p. 33).
Several reaches of the Snake River are classified as water-quality-
impaired due to the presence of one or more pollutants (e.g., Total
Phosphorus (TP), sediments, total coliforms) in excess of State or
Federal guidelines. Nutrient-enriched waters primarily enter the Snake
River via springs, tributaries, fish-farm effluents, municipal waste-
treatment facilities, and irrigation returns (USEPA 2002, pp. 4-18 to
4-24). Irrigation water returned to rivers is generally warmer,
contains pesticides or pesticide byproducts, has been enriched with
nutrients from agriculture (e.g.,
[[Page 52277]]
nitrogen and phosphorous), and frequently contains elevated sediment
loads. Pollutants in fish-farm effluent include nutrients derived from
metabolic wastes of the fish and unconsumed fish food, disinfectants,
bacteria, and residual quantities of drugs used to control disease
outbreaks. Elevated levels of fine sediments, nitrogen, and trace
elements (including cadmium, chromium, copper, lead, and zinc) have
been measured immediately downstream of several aquaculture discharges
(Hinson 2003, pp. 42-45). Additionally, concentrations of lead,
cadmium, and arsenic have been detected in snails collected from the
Snake River (Richards in litt. 2003).
The effects of pollutants detected in the Snake River (e.g.,
metals, pesticides, excess nutrients) on the growth, reproduction, and
survival of the Utah valvata snail have not been evaluated. The Utah
valvata snail has been documented to occur in low-oxygen, organically-
enriched sediments with heavy macrophyte communities downstream of an
aquaculture facility (RM 588) (Hinson 2003, p. 17), indicating that the
species may not be as sensitive to these pollutants as we once
believed. Based on the best available data, we are not aware that water
quality in the Snake River limits growth, reproduction, or survival of
the Utah valvata snail in any portion of its range.
Although several reaches of the Snake River are classified as water
quality impaired (see further discussion below in Factor D), there have
been improvements in Total Suspended Solids (TSS) in certain reaches of
the River, primarily as a result of changing irrigation practices
between 1990 and 2005. There have also been substantial declines in TP
from changing agricultural practices and changing aquaculture feeds in
the middle Snake River downstream of Lake Walcott. Data collected by
the Idaho Department of Environmental Quality (IDEQ) show decreases of
TSS near 64 percent compared to 1990 levels, and decreases of TP near
33 percent compared to 1990 levels (Buhidar in litt. 2006). The
specific water-quality parameters required for the survival and
persistence of the Utah valvata snails are not known. However, the Utah
valvata snail occurs over a relatively large documented range of over
255 river miles (410 km) (USFWS 2005, pp. 110-113) and has the ability
to tolerate and persist in a variety of aquatic habitats with some
degree of water-quality degradation (Lysne and Koetsier 2006, pp. 234-
237). For example, studies conducted by the USBR in 2003 in Lake
Walcott Reservoir indicated the highest Utah valvata snail densities
occurred in the lower reservoir, where the sediments had the greatest
percentage of organic content (an indicator that oxygen levels are
likely low) (Hinson 2006, p. 19).
Summary of Factor A: Our understanding of the habitat needs of the
Utah valvata snail has changed substantially since the species was
listed in 1992. Compared to our knowledge at the time of listing,
survey data collected since 1992 indicate that the geographic range of
the species in the Snake River is approximately 122 river miles (196
km) longer and that the species occurs on a variety of substrate types
(e.g., fines to cobble size) and in varying water flows and depths. The
Utah valvata snail also tolerates a wider range of water-quality
parameters (e.g., dissolved oxygen and temperature) than was originally
believed. Threats pertaining to the construction of new hydropower dams
as cited in the 1992 final rule no longer exist as the plans for dam
construction have expired or been withdrawn. The operation of existing
hydropower dams and reservoirs upstream of Minidoka Dam primarily
affect the distribution of the Utah valvata snail along shoreline areas
due to fluctuating flows and seasonal dewatering; however, the species
persists throughout these reservoirs with relatively high proportional
occurrence. The available information does not suggest that degraded
water quality in the Snake River is affecting the species' population
numbers or distribution. Evidence indicates that improvements have been
made in Snake River water-quality parameters, including TSS and TP in
some Snake River reaches, since listing. Therefore, based on the best
available scientific and commercial data, threats of present or future
destruction, modification, or curtailment of the Utah valvata snail's
habitat or range do not rise to the level such that the species meets
the definition of either endangered or threatened under the Act.
Factor B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
There is no known commercial or recreational use of the species and
collections for scientific or educational purposes are limited in scope
and extent. While collection could result in mortality of individuals
within a small area, they are unlikely to have population-level effects
because only a few individuals and institutions are interested in
collecting the species and the life-history strategy of the species
makes populations relatively resilient to limited mortality (i.e.,
invests little in reproduction, relatively high reproductive output
(many eggs laid at a time), early age of reproduction, and short
lifespan). Therefore, based on the best available scientific and
commercial data, threats from overutilization for commercial,
recreational, scientific, or educational purposes to the Utah valvata
snail do not rise to the level such that the species meets the
definition of either endangered or threatened under the Act.
Factor C. Disease or Predation
Parasitic trematodes similar to those of the genus Microphallus
have been identified in some freshwater snails (e.g., Pyrgulopsis
robusta) that share similar habitats in the Snake River in Idaho
(Dybdahl et al. 2005, p. 8). However, the occurrence of trematode
parasites on the Utah valvata snail has not been studied.
Predators of the Utah valvata snail have not been documented;
however, we assume that some predation by native and nonnative species
occurs. Aquatic snails in general are prey for numerous invertebrates
and vertebrates (Dillon 2000, pp. 274-304), and predation on other
aquatic snails by crayfish and fish is well documented (Lodge et al.
1994, p. 1265; Martin et al. 1992, p. 476; Merrick et al. 1992, p. 225;
Lodge et al. 1998, p. 53; McCarthy and Fisher 2000, p. 387).
While disease or predation likely results in some Utah valvata
snail mortality, the life-history strategy of the species makes
populations relatively resilient to limited mortality (i.e., invests
little in reproduction, relatively high reproductive output (many eggs
laid at a time), early age of reproduction, and short lifespan).
Therefore, based on the best available scientific and commercial data,
threats from disease or predation to the Utah valvata snail do not rise
to the level such that the species meets the definition of either
endangered or threatened under the Act.
Factor D. Inadequacy of Existing Regulatory Mechanisms
In the 1992 final listing rule, we found inadequate regulatory
mechanisms to be a threat because: (1) Regulations were inadequate to
curb further water withdrawal from groundwater spring outflows or
tributary spring streams; (2) it was unlikely that pollution-control
regulations would reverse the trend in nutrient loading any time soon;
(3) there was a lack of State-mandated protections for invertebrate
species in Idaho; and (4) regulations did not
[[Page 52278]]
require FERC or the U.S. Army Corps of Engineers to address Service
concerns regarding licensing hydroelectric projects or permitting
projects under the Clean Water Act (33 U.S.C. 1251 et seq.) for
unlisted snails. Below, we address each of these four concerns.
Groundwater Withdrawal Regulations
Since 1992, new information has become available clarifying the
habitat requirements of the Utah valvata snail. The species is not
limited to cool, fast-water, or lotic habitats, or perennial flowing
waters associated with large spring complexes, as previously believed.
The species is able to live in a variety of aquatic habitats, and is
locally abundant throughout a 255-mile (410 km) stretch of the Snake
River in tributary streams, in the mainstem Snake River, and in
reservoirs that are managed for annual drawdowns.
The Idaho Department of Water Resources (IDWR) manages water in the
State of Idaho. Among the IDWR's responsibilities is the development of
the State Water Plan (IDWR in litt. 1996). The State Water Plan was
updated in 1996, and included a table of federally endangered and
threatened species in Idaho, including five Snake River aquatic snails
listed as endangered or threatened in 1992: The Utah valvata snail,
Idaho springsnail (Pyrgulopsis (=Fontelicella) idahoensis) (delisted in
2007), Snake River Physa (Physa natricina), Bliss Rapids snail
(Taylorconcha serpenticola), and Banbury Springs Lanx (Lanx n sp.
(undescribed)) (see 57 FR 59244). The State Water Plan outlines
objectives for the conservation, development, management, and optimum
use of all unappropriated waters in the State. One of these objectives
is to ``maintain, and where possible enhance water quality and water-
related habitats'' (IDWR in litt. 1996). It is the intent of the State
Water Plan that any water savings realized by conservation or improved
efficiencies is appropriated to other beneficial uses (e.g., fish and
wildlife, hydropower, or agriculture). Another IDWR regulatory
mechanism is the ability of the Idaho Water Resource Board to
appropriate water for minimum stream flows when in the public interest
(IDWR in litt. 2010).
Since 1992, the IDWR and other State agencies have also created
additional regulatory mechanisms that limit future surface and
groundwater development, including the continuation of various
moratoria on new consumptive water rights and the designation of Water
Management Districts (Caswell in litt. 2007). The State is working with
numerous interested parties to stabilize aquifer levels and enhance
cold-water-spring outflows that feed into the Snake River within the
range of the Utah valvata snail. In 2008, the Idaho Legislature
approved House Bill 428 establishing the Statewide Comprehensive
Aquifer Planning and Management Program (SCAPMP) (I.C. section 42-1779)
and House Bill 644 which created the Aquifer Planning and Management
Fund (I.C. section 42-1780) (State of Idaho in litt. 2008a, 2008b).
Under the SCAPMP, the Eastern Snake River Plane Aquifer (ESPA) was
identified for management planning (IDWR 2009, entire). In 2009, the
ESPA Comprehensive Aquifer Management Plan (CAMP) was made final. The
goal of the ESPA CAMP is to ``sustain the economic viability and social
and environmental health of the Eastern Snake Plain by adaptively
managing a balance between water use and supplies'' (IDWR 2009, p. 4).
The ESPA CAMP ``establishes a long-term program for managing water
supply and demand in the ESPA through a phased approach to
implementation, together with an adaptive management process to allow
for adjustments or changes in management techniques as implementation
proceeds'' (IDWR 2009, p. 4). The long-term objective of the ESPA CAMP
is a net increase of 600,000 acre-feet of water annually by the year
2030 (IDWR 2009, p. 4). However, this is a discretionary document and
does not have regulatory authority.
In 2005, Congress and the Idaho Legislature approved the Snake
River Water Rights Agreement (SRWRA) in the Snake River Basin
Adjudication (SRBA) (State of Idaho in litt. 2005a; USA in litt. 2004).
The Snake River Component of the SRWRA allows the USBR to lease up to
427,000 acre-feet of water for flow augmentation, and acquire up to
60,000 acre-feet of water rights from the Snake River between Milner
(RM 639) and Swan Falls (RM 458), increasing total flow augmentation up
to 487,000 acre-feet within the range of the Utah valvata snail (IDWR
in litt. 2004). In 2005, the USBR acquired water rights through a 30-
year lease with the State of Idaho for 98,000 acre-feet of water from
the Bell Rapids Mutual Irrigation Company (State of Idaho in litt.
2005b). This will potentially benefit the Utah valvata snail by
increasing available wetted areas and connectivity of available
habitats within the range of the species.
The State of Idaho established moratoria in 1993 (the year after
the Utah valvata's listing) that restricted further surface-water and
groundwater withdrawals for consumptive uses from the Snake River Plain
aquifer between American Falls Reservoir (RM 714.1) and C.J. Strike
Reservoir (RM 494). The 1993 moratoria, extended by Executive Order in
2004 (Caswell in litt. 2006, attachment 1), have not yet resulted in
stabilization of the Snake River Plain aquifer levels. Depletion of
spring flows and declining groundwater levels are a collective effect
of drought conditions, changes in irrigation practices (the use of
central-pivot sprinklers contribute little to groundwater recharge),
and groundwater pumping (University of Idaho in litt. 2010).
Although we anticipate groundwater levels in the Snake River Plain
aquifer will likely continue to decline in the near future, even as
water-conservation measures are developed and implemented, this is
unlikely to endanger or threaten the Utah valvata snail given the
species' distribution over a 255-mile (410-km) range and its ability to
survive and persist in a wide variety of aquatic habitats not dependent
upon Snake River Plain groundwater outflows.
Pollution Control Regulations
Since 1992, reductions in sediment (TSS) and phosphorus (TP)
loading have improved water quality in localized reaches of the Snake
River (Buhidar in litt. 2005) (see Factor A above). Various State-
managed water-quality programs are being implemented within the range
of the Utah valvata snail. These programs tier off the Clean Water Act
(CWA), which requires States to establish water-quality standards that
provide for (1) the protection and propagation of fish, shellfish, and
wildlife, and (2) recreation in and on the water. As required by the
CWA, Idaho has established water-quality standards (e.g., for water
temperature and dissolved oxygen) for the protection of cold-water
biota (e.g., invertebrate species) in many reaches of the Snake River.
The CWA also specifies that States must include an anti-degradation
policy in their water quality regulations that protects water-body uses
and high-quality waters. Idaho's anti-degradation policy, updated in
the State's 1993 triennial review, is detailed in their Water Quality
Standards (IDEQ in litt. 2009).
The IDEQ works closely with the USEPA to manage point and non-point
sources of pollution to water bodies of the State through the National
Pollutant Discharge Elimination System (NPDES) program under the CWA.
IDEQ has not been granted authority by the USEPA to issue NPDES permits
directly; all NPDES permits are issued by the USEPA Region 10 (USEPA in
litt. 2010). These NPDES permits are written to
[[Page 52279]]
meet all applicable water-quality standards established for a water
body to protect human health and aquatic life. Waters that do not meet
water-quality standards due to point and non-point sources of pollution
are listed on USEPA's 303(d) list of impaired water bodies. States must
submit to USEPA a 303(d) list (water-quality-limited waters) and a
305(b) report (status of the State's waters) every 2 years. IDEQ, under
authority of the State Nutrient Management Act, is coordinating efforts
to identify and quantify contributing sources of pollutants (including
nutrient and sediment loading) to the Snake River basin via the Total
Maximum Daily Load (TMDL) approach. In water bodies that are currently
not meeting water-quality standards, the TMDL approach applies
pollution-control strategies through several of the following programs:
State Agricultural Water Quality Program, Clean Water Act section 401
Certification, Bureau of Land Management (BLM) Resource Management
Plans, the State Water Plan, and local ordinances. Since the time of
listing in 1992, the following TMDLs have been approved by the USEPA
(approval year(s) in parentheses) within the Utah valvata range: The
Big Wood River (2002), Billinglsey Creek (2005), Blackfoot River (2002,
2007), Idaho Falls (2004), Lake Walcott (2000, 2007), Little Wood River
(2005), Palisades (2002), Portneuf River (2001), Raft River (2004),
Snake River--King Hill to C.J. Strike (2006), Middle Snake River--
aquaculture wasteload allocation (2005), and the Teton River (a
tributary of Henry's Fork of the Snake River) and Teton River
Supplement (2003). Implementation plans that specify pollution-control
strategies and monitoring needed to meet TMDL recommendations and goals
are either in place or under development for 9 of these 12 areas
(IDEQ--2010a; 2010b).
State Invertebrate Species Regulations
There are no specific State regulatory protections for the Utah
valvata snail in Idaho. The primary threats to the species, as
identified in our 1992 listing rule, were related to the loss or
alteration of its aquatic habitats. The lack of specific regulations
protecting individual Utah valvata snails does not, by itself, imply
that the species is endangered or threatened.
While there are no State regulatory protections for the Utah
valvata snail, it is considered a Species of Greatest Conservation Need
(SGCN) as identified in the State of Idaho Comprehensive Wildlife
Conservation Strategy (CWCS) (IDFG 2005 p. 4-75). The aim of the CWCS
is to provide a common framework that will enable conservation partners
to jointly implement a long-term approach for the benefit of SGCN
through proactive conservation to promote cost-effective solutions
instead of reactive measures enacted in the face of imminent losses
(IDFG 2005, p. V).
Federal Consultation Regulations
The threat of insufficient regulatory mechanisms to address Utah
valvata conservation needs in the 1992 listing rule was primarily
related to the proposed construction of six hydroelectric dams within
the suspected, limited geographic range of the species, coupled with
our belief at the time of listing that the species required cold, fast-
water, or lotic habitats, and was negatively impacted by dams that
inundated free-flowing river environments. As previously described,
hydroelectric dams are no longer being proposed for construction in the
middle Snake River, and our understanding of Utah valvata snail
geographic range, ecology, and habitat requirements has changed. Thus,
the importance of a regulatory mechanism to address these threats is no
longer a significant issue with regard to the conservation of the Utah
valvata snail.
Summary of Factor D: Although there are no specific State
regulations protecting the Utah valvata snail, it is considered a SGCN
as identified in the Idaho CWCS. The primary threats identified in the
final listing rule were related to the loss or alteration of the
species' habitat. Furthermore, as our understanding of the species'
habitat requirements has changed, so has our understanding of the
species' conservation and regulatory needs. Regulatory mechanisms such
as Idaho's water-quality standards and TMDLs will continue to apply to
habitats occupied by Utah valvata snails. Therefore, based on the best
available scientific and commercial data, threats from inadequate
regulatory mechanisms to the Utah valvata snail do not rise to the
level such that the species meets the definition of either endangered
or threatened under the Act.
Factor E. Other Natural or Manmade Factors Affecting the Species'
Continued Existence
Invasive Species
The final listing rule stated that nonnative New Zealand mudsnails
were not yet abundant in cold-water spring flows with colonies of the
Utah valvata snail, but that they likely did compete with the species
in the mainstem Snake River habitats (57 FR 59254). Surveys have found
that Utah valvata snails and New Zealand mudsnails frequently co-occur
in cold-water spring, mainstem Snake River, and reservoir habitats (37
percent co-occurrence in combined habitat types), which may indicate
that these two species are able to co-exist or that they actually have
slightly different resource preferences (e.g., periphytic vs.
perilithic algae) (Hinson 2006, p. 42). However, Hinson (2006, p. 41)
also notes that the overlap in habitat utilization between the Utah
valvata snail and the New Zealand mudsnail could lead to direct
competition for resources between these two species.
In 2002 and 2004, the USBR reported that New Zealand mudsnails were
increasing in Lake Walcott, yet the densities observed were
substantially lower than those observed in mainstem Snake River
habitats (USBR 2003, p. 19; USBR 2005, p. 6). Further upstream, surveys
conducted throughout American Falls Reservoir indicate that the
distribution of New Zealand mudsnails appears to be limited to the
upper end of American Falls Reservoir near the input of the Snake and
Portneuf rivers (USBR 2003, p. 21), where the habitat is not dewatered
due to water withdrawals for irrigation. Surveys conducted even further
upstream in the Snake River and tributaries (Fields 2005, pp. 8-12)
found moderate-to-high densities of the New Zealand mudsnail at five
sites. However, Fields (2005, p. 10) stated that the current
distribution of New Zealand mudsnails in the Snake River above American
Falls Reservoir could more strongly reflect patterns of introductions
rather than habitat preferences. Populations of the New Zealand
mudsnail are not known to occur in the Wood River, where a small native
or introduced population of the Utah valvata snail is thought to occur.
The overall impact on the Utah valvata snail from the nonnative New
Zealand mudsnail is not fully understood (Lysne 2003, pp. 85-86; Hinson
2006, p. 41). However, after approximately 20 years of co-occurrence,
there is no evidence suggesting that the New Zealand mudsnail has
supplanted or poses an extinction risk to the Utah valvata snail (Gates
in litt. 2009).
Climate Change
There is compelling evidence that we are living in a time of rapid,
worldwide climate change. Although the extent of warming likely to
occur is not known with certainty at this time, the Intergovernmental
Panel on Climate Change (IPCC) has concluded that warming of the
climate is unequivocal, and that continued greenhouse gas emissions at
or above current rates will cause further warming (IPCC 2007, p.
[[Page 52280]]
30). For example, 11 of the last 12 years evaluated (1995-2006) rank
among the 12 warmest years since 1850 (ISAB 2007, p. iii). In the
Pacific Northwest, regionally averaged temperatures have risen 1.5
degrees F (0.8 degrees C) over the last century, and are projected to
increase by another 3 to 10 degrees F (1.5 to 5.5 degrees C) over the
next 100 years (Mote et al. 2003, p. 54; Karl et al. 2009, p. 135).
While the specific effects of global climate change on the Utah valvata
snail are unclear, aquatic species and their habitats may be
particularly vulnerable to changes in temperatures and precipitation
patterns.
Rising temperatures due to climate change can affect aquatic
species, such as the Utah valvata snail, by altering the timing and
precipitation events in the Pacific Northwest (Karl et al. 2009, p.
135). Increased cool season temperatures cause precipitation to fall in
the form of rain as opposed to snow, contributing to earlier snowmelt,
earlier timing of spring runoff, and lower water levels during the warm
season (Karl et al. 2009, p. 135). Many fish and wildlife species in
the Pacific Northwest, especially aquatic species, are dependent on the
timing of spring snowmelt runoff (Karl et al. 2009, p. 135). Areas
along the warmer western slopes of the Cascade Mountains are projected
to see a 30 percent or more reduction in warm season runoff by mid-
century, while the interior, colder areas along the Rocky Mountains are
projected to experience a smaller, 10 percent reduction in spring
runoff (Karl et al. 2009, p. 135). Summer flows will also likely
decrease while water temperature will increase, thereby stressing many
aquatic organisms, especially those that have narrow temperature and
depth requirements.
Despite projected changes in climate in the Pacific Northwest, we
now know the Utah valvata snail is not as specialized in its habitat
needs as we thought at the time of listing and can persist in a broad
range of water flows, depths, and temperatures. In the Snake River, the
species inhabits a diversity of aquatic habitats throughout its 255-
mile (410 km) range, including cold-water springs, spring creeks and
tributaries, mainstem and free-flowing waters, reservoirs, and
impounded Snake River reaches. The species occurs on a variety of
substrate types including both fine sediments and more coarse
substrates in areas both with and without macrophytes. It has been
collected at a wide range of water depths, ranging from less than 3.2
feet (1 meter) to greater than 45 feet (14 meters), and at water
temperatures ranging from 37.4 to 75.2 degrees F (3 to 24 degrees C).
Summary of Factor E: The New Zealand mudsnail frequently co-occurs
with the Utah valvata snail and may be competing for habitat or food.
The New Zealand mudsnail can reach extremely high densities in the
middle Snake River (Richards et al. 2001, p. 375), and has been
recorded at moderate-to-high densities at five sites in tributaries to
the Snake River and the Snake River above American Falls Reservoir.
Populations of the New Zealand mudsnail are not known to occur in the
Wood River. The precise impact on the Utah valvata snail from the
invasion of the New Zealand mudsnail is unknown (Lysne 2003, pp. 85-86;
Hinson 2006, p. 41). However, after approximately 20 years of co-
occurrence, there is no evidence suggesting that the New Zealand
mudsnail has supplanted or caused local extirpations of the Utah
valvata snail.
Further, while numerous scientific studies indicate that the world
is warming due to anthropogenic causes, and that increasing
temperatures will impact precipitation patterns in the Pacific
Northwest, it is difficult at this time to determine the precise
effects this change will have on the Utah valvata snail. Nevertheless,
given the wide variety of habitat conditions, water depths, and
temperature ranges the Utah valvata snail has been found to occupy, the
species is likely to be resilient to moderate changes in temperature
and precipitation patterns. Therefore, threats from other natural or
manmade factors do not rise to the level such that the species meets
the definition of either endangered or threatened under the Act.
Conclusion
As required by the Act, we considered potential threat factors to
assess whether the Utah valvata snail is endangered or threatened
throughout its range. Information collected since the species' listing
in 1992 indicates that the Utah valvata snail is widely distributed and
occurs in a variety of ecological settings over a 255-mile range of the
Snake River. Much of the Snake River within the range of the Utah
valvata is influenced by seasonal dam operations for hydroelectric or
agricultural purposes, yet the species persists in these varied
mainstem Snake River systems, including impounded reservoir habitats
(e.g., Lake Walcott and American Falls reservoirs). None of the threats
that we identified in the 1992 listing determination appear to be
significant to the species (individually or in combination) in light of
our current understanding of its distribution and life history; nor
have we identified any significant new threats to the species.
Therefore, we find that the Utah valvata snail is not in danger of
extinction throughout its range, nor is it likely to become so in the
foreseeable future.
The Service has determined that the original data for
classification of the Utah valvata snail used in 1992 were in error.
However, it is important to note that the original data for
classification constituted the best scientific and commercial data
available at the time and were in error only in the sense that they
were incomplete when viewed in context of the data now available. The
primary considerations to delist the Utah valvata snail are described
in the five-factor analysis above.
Having determined that the Utah valvata snail does not meet the
definition of endangered or threatened throughout its range, we must
next consider whether there are any significant portions of its range
that are in danger of extinction or are likely to become endangered in
the foreseeable future. A portion of a species' range is significant if
it is part of the current range of the species and is important to the
conservation of the species because it contributes meaningfully to the
representation, resiliency, or redundancy of the species. The
contribution must be at a level such that its loss would result in a
decrease in the ability to conserve the species.
Applying the definition described above, we first address whether
any portions of Utah valvata's range warranted further consideration.
Based on a genetic study of the Utah valvata snail (Miller et al.
2006a) and the ecological settings in which the species occurs
throughout its range, three potential population units could be
analyzed as to whether they constituted a significant portion of its
range: The Wood River population unit (WRM 35), the Snake River
population unit (RM 585 through RM 837), and the Hagerman population
unit (isolated springs adjacent to the Snake River at RM 585). We then
evaluated whether each unit constitutes a significant portion of the
range of the species, and if so, whether that portion was endangered or
threatened.
Wood River Population Unit
There is a high degree of uncertainty concerning the distribution
and abundance of the species in the Wood River since there has been
only one documented colony and systematic surveys have not been
conducted. Based on the limited information we have on the Utah valvata
snail in the Wood River, this colony does not appear to exist in an
unusual or unique ecological
[[Page 52281]]
setting or contain a large portion of the habitat or individuals (in
fact, it appears to constitute an extremely small portion of the
overall habitat and number of individuals). Further, a genetics study
conducted by Miller et al. (2006a, pp. 2367-2372) found that the Wood
River occurrence is not genetically divergent or unique from the Snake
River population unit. Because of genetic similarities between Utah
valvata snails in the Snake River and Wood River units, the Wood River
unit could provide some redundancy to the species if the Snake River
unit (see below for further information) is extirpated by a
catastrophic event. However, given that Utah valvata snails are
distributed discontinuously along 255 miles (410 km) of the Snake River
unit, a catastrophic event of the magnitude necessary to simultaneously
eliminate all Utah valvata snail colonies from the Snake River unit is
highly unlikely. In addition, due to the geographic separation of the
Wood River unit from the Snake River unit, it is unlikely that the Wood
River unit would be a significant source of snails to recolonize the
Snake River. Given these factors, we determined the Wood River
population unit did not provide a significant contribution to the
species with regard to redundancy, resiliency, and representation, and
was not evaluated further.
Snake River Population Unit
The Snake River population unit contains the largest and widest
ranging portion of the overall Utah valvata snail population and
contributes substantially to the resiliency, representation, and
redundancy of the species. Other information contributing to its
significance includes: (1) The uppermost reaches of the Snake River
unit, including the Henry's Fork River where Utah valvata snail occurs,
is not influenced by dam and other water management operations, and
water quality is considered to be better than that found in the Wood
River or Hagerman reaches further downstream in the Snake River; (2)
Lower Lake Walcott Reservoir has high densities and high proportional
occurrence of the Utah valvata snail and likely provides refugia for
the species primarily due to the human-induced stability of this
reservoir environment; and (3) genetically, the Snake River population
unit represents the ancestral haplotypes of this species (Miller et al.
2006a, p. 2368). For all of these reasons, we determined that the Snake
River population unit of the Utah valvata snail constitutes a
significant portion of the species' range. The Snake River population
unit was then evaluated to determine if the Utah valvata snail is
endangered or threatened in this portion of its range.
The Utah valvata snail is widely distributed and occurs in a
variety of ecological settings in this population unit, including
impounded reservoir habitats (e.g., Lake Walcott and American Falls
reservoirs). Water quality is relatively good in the upstream (Henry's
Fork) reaches of this unit compared to other population units, and the
New Zealand mudsnail has not become established throughout this unit.
None of the threats that we identified in the 1992 listing
determination appear to be significant to the Utah valvata snail in
this population unit (individually or in combination) in light of our
current understanding of its distribution and life history; nor have we
identified any significant new threats to the species in this unit (see
Rangewide analysis, above). Therefore, we find that the Utah valvata
snail in the Snake River Population Unit is not in danger of
extinction, nor is it likely to become so in the foreseeable future.
Hagerman Population Unit
The best available data indicate that the Hagerman population unit
is likely isolated and separated geographically from other Utah valvata
snail colonies farther upstream that constitute the Snake River
population unit, but overall represents a small area of occupancy
compared to the rest of the range of the species. The geographic
isolation of the Hagerman population unit is an important
consideration; the Miller et al. (2006) genetics paper suggests that
Utah valvata snails found in cold-water spring outflows at the Thousand
Springs Preserve may have been genetically isolated for over 10,000
years and should be evaluated to determine if they can reproduce with
other Utah valvata snails elsewhere in their range. This population
unit also has a unique ecological setting compared to the other two
units, as the species mainly occurs in tributary springs (and at their
cold-water outflows), and not in reservoir or riverine habitats.
In light of the above, we concluded that the Hagerman population
unit may constitute a significant portion of the range of the Utah
valvata snail. The Hagerman population unit was then evaluated to
determine if the Utah valvata snail is endangered or threatened in this
portion of its range.
Currently, water quality is not considered to be a threat that is
of high severity or magnitude to the Hagerman population unit for the
reasons outlined in Factor A of the rangewide analysis. Furthermore,
two cold-water spring outflows, Box Canyon and Thousand Springs,
provide a relatively high-quality and stable aquatic environment for
some Utah valvata snail colonies. Although flows have recently declined
in some cold-water springs due to groundwater withdrawals, and water
quality and quantity could decrease over time if flows are not
preserved, the Utah valvata snail would continue to persist in the
mainstem Snake River in the Hagerman reach where it can tolerate
variable water temperatures and water quality. Although there is
evidence of some density-dependent effects and competition where the
New Zealand mudsnail co-occurs with the Utah valvata snail, the Utah
valvata snail continues to persist in these habitats. Despite
approximately 20 years of co-occurrence of the New Zealand mudsnail and
Utah valvata snail, there is no evidence suggesting that the New
Zealand mudsnail has caused local extirpations of the Utah valvata
snail in Hagerman reach. Therefore, we conclude that the Hagerman
population unit of the Utah valvata snail is not endangered or
threatened in this portion of its range.
In summary, our understanding of the Utah valvata snail's habitat
requirements, range, and threats has changed since the time of listing.
From studies conducted since 1992, we now know that the species occurs
over a much larger geographic range in the Snake River, is able to live
in a variety of aquatic habitats, and is not limited to cold, fast-
water, or lotic habitats, or to perennial flowing waters associated
with large spring complexes, as previously believed. In addition, the
proposed construction of six new hydropower facilities as discussed at
the time of listing is no longer a threat. The Utah valvata snail is
now known to occur in, and persist in, aquatic habitats influenced by
dam operations (e.g., reservoirs, and at elevated water temperatures),
and the species co-exists in a variety of Snake River aquatic habitats
with the invasive New Zealand mudsnail. We have determined that none of
the existing or potential threats, either alone or in combination with
others, are likely to cause the Utah valvata snail to become in danger
of extinction within the foreseeable future throughout all or any
significant portion of its range. The Utah valvata snail no longer
requires the protection of the Act, and, therefore, we are removing it
from the Federal List of Endangered and Threatened Wildlife.
[[Page 52282]]
Effects of This Rule
This rule revises 50 CFR 17.11(h) to remove the Utah (desert)
valvata snail from the List of Endangered and Threatened Wildlife.
Because no critical habitat is designated for this species, this rule
does not affect 50 CFR 17.95.
The prohibitions and conservation measures provided by the Act,
particularly through sections 7 and 9, no longer apply. Federal
agencies are no longer required to consult with us to ensure that any
action they authorize, fund, or carry out is not likely to jeopardize
the continued existence of this species.
Required Determinations
Paperwork Reduction Act of 1995
Office of Management and Budget (OMB) regulations at 5 CFR 1320,
which implement provisions of the Paperwork Reduction Act (44 U.S.C.
3501 et seq.) require that Federal agencies obtain approval from OMB
before collecting information from the public. This rule does not
contain any new collections of information that require approval by
Office of Management and Budget (OMB) under the Paperwork Reduction
Act. This rule will not impose recordkeeping or reporting requirements
on State or local governments, individuals, businesses, or
organizations. An agency may not conduct or sponsor, and a person is
not required to respond to, a collection of information unless it
displays a currently valid OMB control number.
National Environmental Policy Act
We have determined that we do not need to prepare an Environmental
Assessment or Environmental Impact Statement, as defined under the
authority of the National Environmental Policy Act of 1969 (42 U.S.C.
4321 et seq.), in connection with regulations adopted under section
4(a) of the Act. We published a notice outlining our reasons for this
determination in the Federal Register on October 25, 1983 (48 FR
49244).
References Cited
A complete list of all references cited in this rule is available
upon request from the Idaho Fish and Wildlife Office (see ADDRESSES).
Authors
The primary authors of this document are staff members of the Idaho
Fish and Wildlife Office, U.S. Fish and Wildlife Service (see
ADDRESSES).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Regulation Promulgation
0
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; 16 U.S.C. 1531-1544; 16 U.S.C.
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.
Sec. 17.11 [Amended]
0
2. Amend Sec. 17.11(h) by removing the entry for ``Snail, Utah
valvata'' under ``SNAILS'' from the List of Endangered and Threatened
Wildlife.
Dated: August 9, 2010.
Wendi Weber,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2010-20517 Filed 8-24-10; 8:45 am]
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