[Federal Register: June 6, 2007 (Volume 72, Number 108)]
[Proposed Rules]               
[Page 31250-31256]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Fish and Wildlife Service

50 CFR Part 17

Endangered and Threatened Wildlife and Plants; 90-Day Finding on 
a Petition To Remove the Bliss Rapids Snail (Taylorconcha serpenticola) 
From the List of Endangered and Threatened Wildlife

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day petition finding and initiation of status 


SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to remove the Bliss Rapids snail 
(Taylorconcha serpenticola) from the Federal List of Endangered and 
Threatened Wildlife (List) pursuant to the Endangered Species Act 
(Act). We find that the petition presents substantial scientific 
information that delisting the Bliss Rapids snail may be warranted, and 
are initiating a status review. We plan to conduct this review 
concurrent with the ongoing status review initiated on July 27, 2004, 
which we are required to make every 5 years under section 4(c)(2)(A) of 
the Act. We are requesting submission of any new information on the 
Bliss Rapids snail since its original listing as a threatened species 
in 1992. At the conclusion of our status review, we will make the 
requisite recommendation under section 4(c)(2)(B) of the Act and issue 
a 12-month finding on the petition, as provided in section 4(b)(3)(B) 
of the Act.

DATES: The finding announced in this document was made on June 6, 2007. 
To be considered in the 12-month finding on this petition or the 5-year 
review, comments and information must be submitted to us by September 
4, 2007.

ADDRESSES: You may submit new information, materials, comments, or 
questions concerning this species by any one of the following methods:
    1. You may submit comments and information to the Field Supervisor, 
Attention: Bliss Rapids Snail Comments, Snake River Fish and Wildlife 
Office, 1387 S. Vinnell Way, Suite 368, Boise, Idaho 83709.
    2. You may hand-deliver written comments and information to the 
above address.
    3. You may fax your comments to 208-378-5262.
    4. You may go to the Federal rulemaking internet portal: http://www.regulations.gov.
 Follow the instructions for submitting comments.    5. You may e-mail your comments to fw1srbocomment@fws.gov..

    Please include ``Bliss Rapids Snail Comments'' in the subject line 
for faxes and e-mails. Please submit electronic comments in unformatted 
text, and avoid the use of special characters and encryption.

FOR FURTHER INFORMATION CONTACT: Susan Burch, Fish and Wildlife 
Biologist, Snake River Fish and Wildlife Office (see ADDRESSES); 
telephone: 208-378-5243; or e-mail: susan_burch@fws.gov.


[[Page 31251]]

Public Information Solicited

    When we make a finding that substantial information exists to 
indicate that listing or delisting a species may be warranted, we are 
required to promptly commence a review of the status of the species. To 
ensure that the status review is complete and based on the best 
available scientific and commercial information, we are soliciting any 
additional information, comments, or suggestions on the Bliss Rapids 
snail from the public, State and Federal agencies, Tribes, the 
scientific community, industry or environmental entities, or any other 
interested parties. Information sought includes any data regarding 
historical and current distribution, biology and ecology, ongoing 
conservation measures for the species or its habitat, and threats to 
the species or its habitat. We also request information regarding the 
adequacy of existing regulatory mechanisms.
    Please note that comments merely stating support or opposition to 
the actions under consideration without providing supporting 
information, although noted, will not be considered in making a 
determination, as section 4(b)(1)(A) of the Act directs that 
determinations as to whether any species is a threatened or endangered 
species shall be made ``solely on the basis of the best scientific and 
commercial data available.'' At the conclusion of the status review, we 
will issue the 12-month finding on the petition, as provided in section 
4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.).
    If you wish to comment or provide information, you may submit your 
comments and materials concerning this finding to the Field Supervisor 
(see ADDRESSES) by the date listing in the DATES section.
    Before including your address, phone number, e-mail address, or 
other personal identifying information in your comment, you should be 
aware that your entire comment--including your personal identifying 
information--may be made publicly available at any time. While you can 
ask us in your comment to withhold your personal identifying 
information from public review, we cannot guarantee that we will be 
able to do so. If you wish us to withhold your name and/or address, you 
must state this prominently at the beginning of your comment. However, 
we will not consider anonymous comments. Comments and materials 
received will be available for public inspection, by appointment, 
during normal business hours at the address listed in the ADDRESSES 


    Section 4(b)(3)(A) of the Endangered Species Act (Act) of 1973, as 
amended (16 U.S.C. 1531 et seq.), requires that we make a finding on 
whether a petition to list, delist, or reclassify a species presents 
substantial scientific or commercial information indicating that the 
petitioned action may be warranted. The finding is based on information 
contained in the petition and information otherwise available in our 
files at the time we make the finding. To the maximum extent 
practicable, we are to make the finding within 90 days of receiving the 
petition, and publish our notice of the finding in the Federal 
    This finding summarizes the information included in the petition 
and information available to us at the time of the petition review. 
Under section 4(b)(3)(A) of the Act and our regulations in 50 CFR 
424.14(b), our review of a 90-day finding is limited to a determination 
of whether the information in the petition meets the ``substantial 
scientific or commercial information'' threshold. Our standard for 
substantial information with regard to a 90-day petition finding is 
``that amount of information that would lead a reasonable person to 
believe that the measure proposed in the petition may be warranted'' 
(50 CFR 424.14(b)). If we find that substantial information was 
presented, we are required to promptly commence a review of the status 
of the species and publish the results of that status review in a 12-
month finding.

Species Information

    The Bliss Rapids snail (Taylorconcha serpenticola) is found 
primarily on rocky surfaces in riverine and coldwater spring habitats 
along a 65-mile (mi) (105 kilometer (km)) stretch of the Snake River in 
the Hagerman area of southern Idaho (Richards et al. 2006, pp. 34-35). 
They can be locally abundant in springs and spring habitats (Richards 
et al. 2006, pp. 37, 99), but when they occur in non spring influenced 
riverine habitats, it is in low densities (Richards et al. 2006, p 37). 
They are not known to occur in reservoirs or on organic, fine sediments 
(Richards et al. 2006, pp. 21, 23-24). The Bliss Rapids snail appears 
to be a univoltine, meaning it has a 1-year life cycle and the adult 
population is replaced yearly (Hershler et al. 1994, pp. 239-240); 
however, they may have more than one reproductive event within a year 
(Richards 2004, p. 119).
    We listed the Bliss Rapids snail as threatened on December 14, 1992 
(57 FR 59244). At that time, we determined that the Bliss rapids snail 
was threatened by 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). The Bliss Rapids 
snail was described as existing in discontinuously distributed 
populations along 204 river miles (328 river km) in the middle Snake 
River, being primarily concentrated in the Hagerman reach in tailwaters 
of Bliss and Lower Salmon Dams and several unpolluted springs (i.e., 
Thousands Springs, Minnie Miller Springs, Banbury Springs, Niagara 
Springs, and Box Canyon Springs). We finalized the Snake River Aquatic 
Species Recovery Plan, which included the Bliss Rapids snail, in 1995 
(Service 1995). Critical habitat has not been designated for this 

Review of Petition

    On December 26, 2006, we received a petition from the Governor of 
Idaho and the Idaho Power Company (IPC) requesting that the Bliss 
Rapids snail be removed from the List. The delisting petition cites a 
recent status review conducted by Richards et al. (2006), a review of 
Bliss Rapids snail sampling methodology prepared by Steward & 
Associates (2006), and information and data submitted to the Service at 
an August 24, 2006, informational meeting as support for their petition 
(Idaho 2006 in litt.). The petition clearly identified itself as a 
petition and included the requisite identification information for the 
petitioners, as required in 50 CFR 424.14(a). The petition cited 
information on the natural history of the Bliss Rapids snail, its 
population status, and advances in our understanding of the species' 
ecology and threats since listing. The petition states that many of the 
threats identified in the 1992 listing rule are no longer viable or 
have been attenuated by subsequent actions. It also states that the 
Bliss Rapids snail is more abundant, is more continuously distributed, 
and exists in more diverse habitats than previously recorded.

Threats Analysis

    The factors for listing, delisting, or reclassifying a species are 
described at 50 CFR 424.11. We may delist a species only if the best 
scientific and commercial data available substantiate that it is 
neither endangered nor threatened. Delisting may be warranted as a 
result of: (1) Extinction, (2) recovery, and/or (3) a determination 
that the original data used for classification

[[Page 31252]]

of the species as endangered or threatened were in error.
    Section 4(a)(1) of the Act requires that we determine whether a 
species is endangered or threatened based on one or more of the five 
following factors: (A) Present or threatened destruction, modification, 
or curtailment of habitat or range; (B) 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. In 
making this 90-day finding, we evaluated whether information presented 
in the December 2006 petition, when considered along with information 
in our files, constitutes substantial scientific or commercial 
information such that delisting may be warranted. Our evaluation of 
this information is presented below.

A. Present or Threatened Destruction, Modification, or Curtailment of 
the Species' Habitat or Range

Habitat Use
    Petitioners claim that Bliss Rapids snails are able to live in a 
variety of habitats previously thought to be unsuitable for the 
species, including reservoirs, based primarily on a status report by 
Richards et al. (2006). Richards et al. (2006, p. 3) reviewed the 
available information on Bliss Rapids snail collections and reported 
that the species has been found in areas of the Snake River that do not 
have known spring influence. However, the likelihood of Bliss Rapids 
snail occurrence decreased with increasing temperature in riverine 
habitats (Richards et al. 2006, p. 42), and the highest mean density 
for the spring-influenced habitat in the Snake River was 307.2 snails 
per meter-squared (m2), compared to the highest mean density 
in non spring influenced habitat of 11.7 snails per m2 
(Richards et al. 2006, p. 37). Richards et al. (2006, p. 54) also 
reported that more Bliss Rapids snails were found in shallow depths 
than in deeper ones. Of 607 samples taken in the 3 reservoirs within 
the range of the Bliss Rapids snail, none contained Bliss Rapids snails 
(Richards et al. 2006, pp. 38-39), and, therefore, the Richards et al. 
(2006) study does not support the petitioners' claim that reservoirs 
are suitable habitat. Their absence from reservoirs and areas of 
organic, fine sediments suggests that this species may be limited to 
aerobic substrates flushed by moving water (Richards et al. 2006, p. 
    At the time of listing, in 1992, we stated that: ``Bliss Rapids 
snails occur on stable, cobble-boulder substratum only in flowing 
waters in the unimpounded reaches of [the] mainstem Snake River and 
also in a few spring alcove habitats in the Hagerman Valley. The 
species does not burrow in sediments and normally avoids surfaces with 
attached plants. Known river populations (or colonies) of the Bliss 
Rapids snail occur only in areas associated with spring influences or 
rapids edge environments and tend to flank shorelines. They are found 
at varying depths if dissolved oxygen and temperature requirements 
persist and are found in shallow (<  1 cm (.4 in)) permanent cold 
springs (Frest and Johannes 1992a)'' (57 FR 59245).
    Information in our files suggests that populations are consistently 
larger, at least in terms of density and relative abundance, in 
coldwater springs and spring-fed tributaries compared to mainstem Snake 
River locations (Stephenson and Bean 2003, p. 12; Stephenson et al. 
2004, pp. 14, 24; Clark et al. 2005, pp. 7, 46-47; Richards et al. 
2006, pp. 37-38, 97-99), and the likelihood of Bliss Rapids snail 
occurrence decreases with increasing water temperature in riverine 
habitats (Richards et al. 2006, p. 42).
    Based on information presented by the petitioner, along with 
information in our files, most of the basic habitat requirements for 
Bliss Rapids snails are reaffirmed. Current information documents the 
occurrence of low densities of Bliss Rapids snails in Snake River 
reaches without obvious spring influence (based on visual inspection). 
The petitioners' claim that Bliss Rapids snails can live in reservoirs 
is not supported by the information provided. In fact, data provided by 
the petitioner strongly suggest that reservoirs do not provide suitable 
habitat for the species and likely impede metapopulation connectivity 
(Richards et al. 2006, pp. 38-39, p. 119).
    The petitioners claim that the species is more widely distributed 
than previously known. They provided a status report by Richards et al. 
(2006) as the primary source of information to support their claim. 
Richards et al. (2006, pp. 33-34) found that, as of 2006, the Bliss 
Rapids snail was documented at 837 collection points in the free-
flowing mid-Snake River, as compared with less than 15 collection 
points at the time of listing. Richards et al. (2006, pp. 119, 123) 
also state that Bliss Rapids snails exist as possibly 27 discontinuous 
populations along the Snake River, including 5 within river habitats 
and 22 in spring or spring-influenced habitats. Richards et al. (2006, 
pp. 34-35) state that Bliss Rapids snails were recorded in every one of 
the 22 non-reservoir miles (35 km) from River Mile (RM) 547.7, upstream 
to the head of Upper Salmon Falls Reservoir at RM 589.2 (a distance of 
41.5 river miles (66.8 river km)). A total of 19.5 of those 41.5 river 
miles (31.4 of those 66.8 river km) are in-reservoir habitat, and 
therefore are not suitable for Bliss Rapids snails.
    At the time of listing we stated that: ``Based on live collections, 
the species currently exists as discontinuously distributed populations 
over 204 river miles within its historic range. These populations are 
primarily concentrated in the Hagerman reach in tailwaters of Bliss and 
Lower Salmon Dams and several unpolluted springs (i.e., Thousand 
Springs, Minnie Miller Springs, Banbury Springs, Niagara Springs, and 
Box Canyon Springs)'' (57 FR 59245).
    Information in our files now suggests that the farthest upstream 
population noted in the listing rule (i.e., the observation above 
American Falls at RM 749.8 (57 FR 59243)) may have been in error. 
Several factors, when considered together, support this conclusion: (1) 
The reported observation is 151 river miles (243 river km) away from 
the nearest confirmed location of the Bliss Rapids snail (i.e., Niagara 
Springs at RM 599), (2) the vouchered specimen cannot be located, and 
(3) hundreds of samples for snails have been collected in and above 
American Falls Reservoir since the reported collection without further 
evidence of the species at that location.
    Given the information provided by the petitioner and other 
information in our files, we now know the Bliss Rapids snail to be 
distributed discontinuously over approximately 65 river miles (105 
river km), rather than over 204 river miles (328 river km), as we 
stated in the listing rule (57 FR 59243). However, if we discount the 
observation above American Falls, which we now believe to be 
unreliable, the species is more widely and more continuously 
distributed than previously thought (Richards et al. 2006, p. 28).

Construction of New Hydropower Dams

    The petition states that threats to Bliss Rapids snail habitat from 
future hydro-power development are not as they were perceived when the 
species was listed in 1992. The petitioners provided the following 
documents as evidence that hydropower permits are no longer moving 
forward: (1) A 2002 notice of surrender of preliminary permit for the 
River Side Project (Federal Energy Regulatory Commission (FERC) 2002), 
(2) 2002 Federal Energy Regulatory

[[Page 31253]]

Commission (FERC) orders denying application for preliminary permits 
for the Eagle Rock and Star Falls Hydroelectric Projects (FERC 2002a, 
2002b), and (3) a 2003 notice of surrender of preliminary permit for 
the Auger Falls Project (FERC 2003). The petitioners also provided 
documents from the State of Idaho (Idaho 2006) and Richards et al. 
(2006) indicating that all recent permits for the construction of new 
dams along the Mid-Snake River reach where the Bliss Rapids snail 
occurs have either lapsed or have been denied by the FERC.
    At the time of listing, there were six active proposals for new 
hydroelectric projects in the middle-Snake River. In our listing rule, 
we stated: ``Six proposed hydroelectric projects, including two high 
dam facilities, would alter free flowing river reaches within the 
existing range of [the Bliss Rapids snail]. Dam construction threatens 
the [Bliss Rapids 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 mollusk 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 
    We have no information in our files suggesting that future 
hydropower development in the middle-Snake River is likely to occur; 
therefore, we accept the petitioner's claim that the threats from 
hydropower development have dissipated since the time of listing.
Operation of Existing Hydropower Dams
    The status report provided by the petitioner (Richards et al. 2006) 
states that threats to Bliss Rapids snail habitat from the operation of 
hydropower dams (i.e., peak loading) are not as they were perceived 
when the species was listed in 1992. Richards et al. (2006, p. 92) 
state that free-flowing Bliss Rapids snail habitat downstream of the 
dams is improved because fine sediments settle in the reservoirs above 
the dams, resulting in reduced fine sediments and increased rocky 
substrates, the preferred habitat of the Bliss Rapids snail, downstream 
of the dam. They also state that rapid changes in flow below hydropower 
dams have not eliminated Bliss Rapids snails from shallow shoreline 
areas; on the contrary, highest densities of riverine Bliss Rapids 
snail populations directly below hydropower dams occurred in the zones 
of highest flow fluctuations (Richards et al. 2006, p. 92).
    Richards et al. (2006) cite a laboratory exposure study (Richards 
2006) that concluded Bliss Rapids snails could survive for many hours 
to several days in moist conditions (i.e., undersides of cobbles) when 
air temperatures were greater than 32 [deg]F (0 [deg]C). In an ongoing 
field study, Richards (unpublished data, cited in Richards et al. 2006, 
pp. 125-126) also found that Bliss Rapids snails could survive on the 
damp undersides of exposed cobbles alongside the mid-Snake River for up 
to several days. Because fluctuation of water levels due to load-
following only occurred for several hours at a time (William H. Clark, 
Idaho Power Company, personal communication, cited in Richards et al. 
2006, p. 126), Richards et al. (2006, pp. 125-126) concluded that 
direct mortality to Bliss Rapids snails from exposure due to load-
following events should be minimal. The petitioners did not provide any 
data that assesses the sub-lethal effects (e.g., impacts to 
reproduction, food sources, etc.) of peak-loading.
    At the time of listing, we stated: ``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 also 
threatens [the Bliss rapids snail]. Peak-loading is a frequent and 
sporadic practice that results in dewatering mollusk habitats in 
shallow, littoral shoreline areas * * * these diurnal water 
fluctuations prevent the [Bliss Rapids snail] from occupying the most 
favorable habitats.''
    Information in our files suggests that air temperatures within the 
range of Bliss Rapids snails regularly fall below 32 [deg]F (0 [deg]C) 
between November and March (Richards 2006, p. 28) and that the amount 
of time Bliss Rapids snails can survive while exposed to air 
temperatures below freezing is significantly less than at 32 [deg]F (0 
[deg]C) (e.g., in less than an hour, half of the individuals in a 
laboratory trial subjected to a temperature of 19 [deg]F (-7 [deg]C) 
died) (Richards 2006, p. 12). Therefore, peak-loading during winter 
months may cause Bliss Rapids some snail mortality (Richards 2006, p. 
15), but field studies have not been conducted to assess the likely 
impact on the population. Furthermore, we have no data in our files 
that assesses the sub-lethal effects of peak-loading on Bliss Rapids 
    Although there are some uncertainties regarding the actual effects 
of peak-loading on Bliss Rapids snails in the wild, the petitioners 
have presented substantial information suggesting that the threats from 
peak-loading may be less than we perceived at the time of listing.
Water Quality
    The status report provided by the petitioner (Richards et al. 2006, 
pp. 5-6) states that threats to Bliss Rapids snail habitat from water 
pollution are not as they were perceived when the species was listed in 
1992. Richards et al. (2006, pp. 5-6, 86) state that significant 
nutrient and sediment reduction has occurred in the Snake River 
following implementation of the Idaho Nutrient Management Act and 
regulated Total Maximum Daily Load (TMDL) reductions from the mid-1990s 
to the present.
    Hypereutrophy (planktonic algal blooms and nuisance rooted aquatic 
plant growths), prior to listing in 1992, was very severe during 
drought cycles when deposition of sediments and organic matter 
blanketed river substrate, often resulting in unsuitable habitat 
conditions for Bliss Rapids snails. Although some nutrient and sediment 
reduction has occurred since listing (Richards et al. 2006, p. 5), 
water quality of the river from RM 600 to 589 is subject to ``very 
large inflows'' of agriculture and aquaculture wastewater flowing to 
the river below Twin Falls to lower Salmon Falls dam at RM 572; as a 
result, nutrient and sediment concentrations increase during low summer 
flows (Richards et al. 2006, p. 91). Furthermore, the highest densities 
and occurrence frequencies of Bliss Rapids snails in riverine habitats 
were immediately downstream of the mid-Snake river reach considered to 
be the most seriously polluted reach of the river (from Shoshone Falls 
downstream to Upper Salmon Falls Dam (Richards et al. 2006, p. 33)).
    Information in our files shows that phosphorus concentrations, the 
key nutrient leading to hypereutrophic conditions in the middle Snake 
River, exceeded Environmental Protection Agency (EPA) guidelines for 
the control of nuisance algae at numerous locations along the Snake 
River from 1989 to 2002, including areas immediately upstream of Bliss 
Rapids snail colonies (Hardy et al. 2005, p. 13). Several water quality 
assessments have been completed by the EPA, U.S. Bureau of Reclamation 
(USBR), and IPC, and all generally agree that water quality in the 
Snake River of southern Idaho meets Idaho water quality standards for 
aquatic life for some months of the year, but may not meet these 
standards when temperatures are high and flows are low

[[Page 31254]]

(Meitl 2002, p. 33). Idaho Department of Environmental Quality's (IDEQ) 
2005 performance and progress report to the EPA states that projects 
are meeting the Idaho non-point source pollution program goals (IDEQ 
2006, p. 8). However, others report that water quality has not improved 
appreciably between 1989 and 2002 (Hardy et al. 2005, pp. 19-21, 49, 
    Although the highest densities and occurrence frequencies of Bliss 
Rapids snails in riverine habitat were recorded immediately downstream 
of the mid-Snake River reach considered to be the most seriously 
polluted reach of the river (from Shoshone Falls downstream to Upper 
Salmon Falls Dam), this reach also receives a large infusion of 
coldwater spring outflow. No riverine Bliss Rapids snails were detected 
upstream of Upper Salmon Falls Dam (Richards et al. 2006, pp. 31-32, 
    Given the information provided by the petitioner and other 
information in our files, we find that there are some uncertainties 
regarding the effects of degraded water quality in the Snake River on 
Bliss Rapids snails; however, we believe the petitioners have presented 
substantial information suggesting that the threats from degraded water 
quality may be less than we perceived at the time of listing.
Water Diversions (Springs)
    The status report provided by the petitioner (Richards et al. 2006, 
p. 6) states that some coldwater spring habitats within the range of 
the Bliss Rapids snail previously threatened by water development have 
been preserved in corporate or public trusteeship.
    Information in our files shows that springs occupied by Bliss 
Rapids snails that are protected from further water development include 
Thousand Springs, Box Canyon Springs (Newcomer in litt. 2005), and 
Banbury Springs (Holmstead and Holthuijzen 2005). However, there are 
hundreds of other springs in the Hagerman Valley, and nearly all exist 
on private land in areas that have not been surveyed for Bliss Rapids 
snails due to lack of access. We do not know whether these springs are 
being protected or whether they have already been developed for 
aquaculture, hydropower, or irrigation water.
    Based on information provided by the petitioner, along with other 
information in our files, some spring habitats occupied by Bliss Rapids 
snails are being protected in preserves. However, the status of 
coldwater springs on some private lands remains largely unknown.

Water Diversions (Snake River)

    The status report provided by the petitioner (Richards et al. 2006, 
p. 5) states that threats to Bliss Rapids snail habitat from diversion 
of water from the Snake River for irrigation and aquaculture are not as 
they were perceived when the species was listed in 1992. According to 
Richards et al. (2006, p. 83), over the past 35 years, the river has 
experienced higher energy flushing cycles than in the prior 60 years. 
High mean annual flows reached approximately 18,000 cubic feet per 
second (cfs) in 1984 and 1997. In 2006, flushing flows had again 
occurred with sustained mean daily flows at King Hill in excess of 
20,000 cfs (Richards et al. 2006, pp. 83-84).
    At the time of listing, we stated: ``Water quality continues to 
degrade in the middle Snake River from increased water use and 
withdrawal, aggravated by recent drought-induced low flows. This 121 
mile (195 kilometer) stretch of the Snake River [i.e., the middle Snake 
River] is impacted by agricultural return flows; runoff from between 
500 and 600 dairies and feedlots; effluent from over 140 private, 
state, and Federal fish culture facilities; and point source (e.g., 
municipal sewage) discharges (Idaho Department of Health and Welfare 
(IDHW) 1991a). These factors contribute to increased nutrient loads and 
concentrations which in turn adversely impact the lotic species. 
Nutrient loading contributes to dense blooms of free-living and 
attached filamentous algae, which the species cannot utilize. This 
algae will often cover rock surfaces, effectively displacing suitable 
snail habitats and food resources. Stream sediments also become anoxic 
as high biochemical oxygen demand during the aquatic growing season and 
seasonal algae die offs occur.''
    We accept the characterization of the flow data at King Hill 
provided by the petitioner. However, the petitioners have not explained 
how a few years of flushing flows reduces the threat of high 
concentrations of pollutants due to low Snake River flows in other 
years. Therefore, we find that the petition has not presented 
substantial information suggesting that threat of mainstem Snake River 
water diversions to Bliss Rapids snails has diminished.
Groundwater Mining
    The status report provided by the petitioner (Richards et al. 2006, 
p. 5) states that threats to Bliss Rapids snail coldwater spring 
influenced habitats from groundwater mining for irrigation and 
aquaculture are not as they were perceived when the species was listed 
in 1992. Average annual spring flows increased from about 4,400 cfs in 
1910 to approximately 6,500 cfs in the early 1960s because of 
widespread flood irrigation causing artificial recharge of the aquifer 
(Richards et al. 2006, p. 84, 87). As a result of more efficient water 
practices from 1960 to the present (i.e., switching from flood 
irrigation to more efficient center-pivot irrigation systems) more 
water was pumped from the aquifer while water percolation into the 
aquifer declined, resulting in declines in average annual spring flows 
to about 5,000 cfs (Richards et al. 2006, pp. 84, 87).
    The petitioners also provided a number of documents indicating that 
there is a moratorium on some groundwater development in the eastern 
Snake River plain (Idaho 2004) and that there are current efforts to 
artificially recharge the Snake River aquifer to stabilize or increase 
spring flows (Idaho 2005). These efforts have the potential to benefit 
the Bliss Rapids snails, but their effects have not yet been realized 
in terms of stable or increasing spring flows (Richards et al. 2006, p. 
    Information in our files shows that there are several in-stream 
flow targets, set by the State of Idaho, which have the potential to 
conserve populations of Bliss Rapids snails (IDWR 2006a). However, 
water rights with earlier priority dates have the right to fill their 
needs before the minimum stream flow is considered. Senior diversions 
can legally dewater the stream in a drought year or when low flows 
occur, leaving no water for the minimum stream flow (IDWR 2006b). 
Therefore, the current and future conservation benefits of recently 
established in-stream flow targets for the Bliss Rapids snail are 
    Information provided by the petitioner, along with other 
information in our files, indicates that the State of Idaho has taken 
steps to improve groundwater recharge, and limit new groundwater 
development with the eastern Snake River plain; however, the Snake 
River Plain aquifer level continues to decline and instream-flow 
targets and moratoriums on new groundwater development do not prevent 
those with senior water rights from diminishing flows in drought years 
or during low flows. Therefore, we find that the petitioners have not 
presented substantial information indicating that the threat of 
groundwater mining to the Bliss Rapids snail may be less than the best 
available information indicated at the time of listing in 1992.

[[Page 31255]]

B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The petitioners did not provide information regarding the 
overutilization of Bliss Rapids snails for commercial, recreational, 
scientific, or educational purposes, and we do not have information in 
our files suggesting that this factor is a threat to the species.

C. Disease or Predation

    The petitioners did not provide information regarding the effects 
of disease or predation on Bliss Rapids snails. At the time of listing, 
we stated that changes in the fish fauna of the middle Snake River had 
been suggested as a potential threat to the Bliss Rapids snail (57 FR 
59254). At that time, we had no data to support this suggestion, and we 
still have no information in our files suggesting that disease or 
predation are significant threats to the Bliss Rapids snail.

D. The Inadequacy of Existing Regulatory Mechanisms

    The petitioners provided numerous documents regarding water rights, 
aquifer recharge, and groundwater management in the Snake River and 
Snake River Plain aquifer (Idaho 2006 in litt.). These documents 
indicate that the State of Idaho has regulatory mechanisms to limit or 
exclude the development of new surface water or groundwater rights 
within the range of the Bliss Rapids snail. These documents also 
indicate that the State has regulatory mechanisms to prioritize 
existing water rights based on seniority.
    At the time of listing, 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 protections for invertebrate species in Idaho, and (4) 
regulations did not require FERC or the U.S. Army Corp of Engineers to 
address Service concerns regarding licensing hydroelectric projects or 
permitting projects under the Clean Water Act for unlisted snails.
    Information provided by the petitioner, along with information in 
our files, suggests that the threat to Bliss Rapids snails from 
inadequate regulatory mechanisms may be less than we perceived at the 
time of listing. Although there are no regulatory mechanisms in place 
to prevent senior diversions under current water rights allocations 
from dewatering the stream (see Groundwater Mining section above), 
there are now regulatory mechanisms to limit future surface water and 
groundwater development, and some pollution control regulations have 
been implemented (see Water Quality section above).

E. Other Natural or Manmade Factors Affecting Its Continued Existence

    The status report provided by the petitioner (Richards et al. 2006, 
p. 5) states that threats to the Bliss Rapids snail from the New 
Zealand mudsnail (Potamopyrgus antipodarum) are not as they were 
perceived when the species was listed in 1992. Richards et al. (2006, 
p. 6) note that the New Zealand mudsnail has not caused any local 
extirpations of Bliss Rapids snails, and that they have not colonized 
headwater spring habitats. However, in areas where the species do 
coexist, Richards et al. (2006, pp. 61, 64, 68) found that Bliss Rapids 
snails may be competitively excluded by New Zealand mudsnails, and that 
Bliss Rapids snail densities would be higher in the absence of New 
Zealand mudsnails.
    At the time of listing, we stated that New Zealand mudsnails were 
not abundant in coldwater springflows with colonies of Bliss Rapids 
snails, but that they did compete with the Bliss Rapids snail in the 
mainstem Snake River (57 FR 59254). We have no direct evidence that New 
Zealand mudsnails have displaced colonies of Bliss Rapids snails, but 
New Zealand mudsnails have been documented in dark mats at densities of 
nearly 400 individuals per square inch in free-flowing habitats within 
the range of the Bliss Rapids snail (57 FR 59254). Furthermore, New 
Zealand mudsnails have become established in every spring-fed creek or 
tributary to the Hagerman Reach that has been surveyed (USFWS 2007).
    Based on information provided by the petitioner, along with 
information in our files, New Zealand mudsnails appear to limit Bliss 
Rapids snail densities, except in headwater spring habitats. Although 
the information provided by the petitioners clarifies our understanding 
of competitive interactions between New Zealand mudsnails and Bliss 
Rapids snails, the primary conclusions of their review are consistent 
with our analysis at the time of listing. Therefore, we find that the 
petitioners have not provided substantial information indicating that 
the threats to Bliss rapids snails from New Zealand mudsnails may be 
less than the best available information indicated at the time of 
listing in 1992.


    We have reviewed the delisting petition and the supporting 
documents, as well as other information in our files. We find that the 
delisting petition and other information in our files presents 
substantial information that delisting the Bliss Rapids snail may be 
warranted, and we are initiating a status review. Petitioners have 
provided a detailed status report that updates the state of knowledge 
regarding Bliss Rapids snail habitat use, distribution, and threats. 
The status report provides substantial information indicating that the 
Bliss Rapids snail is more widely distributed in the Hagerman area of 
southern Idaho than previously recorded, that it has been documented in 
areas without obvious spring influence based on visual inspections, and 
that threats from hydropower development and ongoing operation of 
hydropower dams may not be what we perceived when we listed the species 
in 1992. The status report also provides substantial information 
indicating that additional regulatory mechanisms now exist that could 
limit water development and water pollution in Bliss Rapids snail 
habitat. Based on our review of the petition and information in our 
files, other threats to the species remain, but we will fully evaluate 
these and determine whether or not delisting is warranted, in our 12-
month finding in accordance with section 4(b)(3)(B) of the Act.
5-Year Review
    Section 4(c)(2)(A) of the Act requires that we conduct a review of 
listed species at least once every 5 years. We are then, under section 
4(c)(2)(B), to determine whether or not any species should be removed 
from the List (delisted), or reclassified from endangered to 
threatened, or threatened to endangered. We initiated a 5-year review 
for the Bliss Rapids snail on July 27, 2004 (69 FR 44676). Because we 
are initiating a 12-month finding with this notice, and because the 12-
month finding and 5-year review serve a similar purpose (i.e., to 
determine the appropriate classification of a species under the Act), 
the results of our 12-month finding will be adopted for our 5-year 


    A complete list of all references cited in this finding is 
available, upon request, from the Snake River Fish and Wildlife Office 
(see ADDRESSES section).


    The primary author of this document is Jesse D'Elia, Pacific 
Regional Office, Portland, Oregon.

[[Page 31256]]


    The authority for this action is section 4 of the Endangered 
Species Act of 1973 (16 U.S.C. 1531 et seq.).

    Dated: May 25, 2007.
Randall B. Luthi,
Acting Director, Fish and Wildlife Service.
[FR Doc. 07-2812 Filed 6-5-07; 8:45 am]