[Federal Register: April 29, 2003 (Volume 68, Number 82)]
[Page 22724-22727]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Fish and Wildlife Service

Endangered and Threatened Wildlife and Plants; 90-day Finding for 
a Petition To List the Midvalley Fairy Shrimp as Endangered

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 for a petition to list the midvalley fairy shrimp 
(Branchinecta mesovallensis) under the Endangered Species Act of 1973, 
as amended. We find the petition presents substantial information to 
indicate that listing may be warranted. We are therefore initiating a 
status review of the species, and will issue a 12-month finding to 
determine if the petitioned action is warranted. To help ensure the 
review is comprehensive, we are soliciting information and data 
regarding this species.

DATES: The finding announced in this document was made on April 18, 
2003. To be considered in the 12-month finding on this petition, 
comments and information should be submitted to us by June 30, 2003.

ADDRESSES: The complete file for this finding is available for 
inspection, by appointment, during normal business hours, at the 
Sacramento Fish and Wildlife Office, U.S. Fish and Wildlife Service, 
2800 Cottage Way, Sacramento, CA 95825-1846. Submit new information, 
materials, comments, or questions concerning this species to the 
Service at the above address.

FOR FURTHER INFORMATION CONTACT: Glen Tarr, at the address given above 
(telephone 916/414-6652; facsimile 916/414-6713; electronic mail: 



    Section 4(b)(3)(A) of the Endangered Species Act of 1973, as 
amended (Act) (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. We are to base this finding on all 
information available to us at the time we make the finding. To the 
maximum extent practicable, we must make this finding within 90 days of 
receiving the petition and publish the notice of the finding promptly 
in the Federal Register. Our standard for substantial information 
within the Code of Federal Regulations (CFR) 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 the finding is that 
substantial information was presented, we are required to promptly 
commence a review of the status of the species, if one has not already 
been initiated, under our internal candidate assessment process.
    On August 31, 2001, we received a petition dated August 14, 2001 
submitted by the Center for Biological Diversity and VernalPools.Org. 
The petition requests us to list the midvalley fairy shrimp as an 
endangered species, to designate critical habitat for the species, and 
to list the species on an emergency basis. The petition presents 
extensive information regarding the biology of the midvalley fairy 
shrimp and threats to the species, which we address below. We have 
reached our 90-day finding on this petition in accordance with a 
consent decree that requires us to complete a finding by April 21, 2003 
(Butte Environmental Council v. Wayne White, Consent Decree, CIV.S-00-
797 WBS).

Biology and Distribution

    The midvalley fairy shrimp is a small (7 to 20 millimeter (mm) 
(0.28 to 0.79 inch (in)), freshwater crustacean that lives in vernal 
pools, vernal swales and other ephemeral water bodies near the middle 
of California's Central Valley (Helm 1998; Eriksen and Belk 1999; Belk 
and Fugate 2000). It is known from 52 occurrences in seven California 
counties: Sacramento, Solano, Contra Costa, San Joaquin, Merced, Madera 
and Fresno (California Natural Diversity Data Base (CNDDB) 2002). 
Midvalley fairy shrimp populations survive the seasonal desiccation of 
their pools by laying dormant eggs called cysts, which can withstand 
extreme temperatures, the digestive tracts of animals and, if 
necessary, years of dessication before hatching. Since not all cysts 
hatch with any given refilling of their pool, the cysts form a ``bank'' 
in the soil from which new populations of adults may develop, even in 
pools that have not had adults for years (Eriksen and Belk 1999).
    The habitat requirements and life history characteristics of the 
midvalley fairy shrimp are similar to those of four other shrimp 
species that we listed in 1994: the Conservancy fairy shrimp 
(Branchinecta conservatio), longhorn fairy shrimp (B. longiantenna), 
vernal pool fairy shrimp (B. lynchi), and vernal

[[Page 22725]]

pool tadpole shrimp (Lepidurus packardi) (59 FR 48136; September 19, 
1994). However, the midvalley fairy shrimp has a smaller overall range, 
and tends to use shallower pools, than these other species.

Analysis of Threats

    As the petition points out, we acknowledged in our 1994 listing of 
four other vernal pool shrimp species (59 FR 48136) that California's 
remaining vernal pools have been under severe pressure from urban 
development, agricultural conversion and associated hydrological 
changes. The petition also points to evidence of high annual losses of 
vernal pool habitat prior to 1997 (Holland 1998), high population 
growth estimates, and threats from specific proposed development 
projects such as the new University of California (UC) Merced campus. 
We believe the petition substantially supports the case that loss of 
habitat may constitute a threat to vernal pool species. It is less 
clear, however, to what extent existing regulatory mechanisms may 
ameliorate that threat in the case of the midvalley fairy shrimp.
    Section 7 of the Act requires Federal agencies to ``insure that any 
action authorized, funded or carried out by such agency . . . is not 
likely to jeopardize the continued existence of any endangered species 
or threatened species or result in the destruction or adverse 
modification of [critical habitat].'' To that end, Federal agencies are 
required to consult with us on projects likely to affect listed species 
in the project area, and to obtain from us a biological opinion 
detailing the reasonable and prudent alternatives (if any) that the 
project applicant must take to avoid jeopardy or adverse modification 
(16 U.S.C. 1536). For projects affecting vernal pool habitat, we 
interpret this to mean that if a listed vernal pool species may occur 
in the same 7.5' quadrangle (the area covered by a 1:24,000 scale USGS 
topological map) as the project, the applicant must typically conduct 2 
years of surveys to demonstrate that the listed species is not present 
(Service 1996). The discovery of a listed species likely to be affected 
by the project triggers the need for section 7 consultation and 
appropriate documentation.
    All of the known midvalley fairy shrimp occurrences are in 
quadrangles that are either known to contain, or may contain, 
occurrences of at least one of the four listed vernal pool shrimp 
species mentioned under Factor A, above (CNDDB 2002; Service in litt., 
2003a; Service, in litt., 2003b). Consequently, prospective developers 
requiring a Federal permit (such as a permit to fill vernal pools under 
section 404 of the Clean Water Act (CWA)) would already have to survey 
for listed species prior to developing midvalley fairy shrimp pools in 
those quadrangles. Although the petition argues that vernal pools with 
midvalley fairy shrimp and no listed species would not be protected 
under section 7, this is only true as applied to vernal pool complexes 
with no listed species rather than to single pools. We define 
populations of listed vernal pool shrimp according to occupied 
complexes rather than by single pools (Service 2002a) because cysts in 
individual pools may wait several years to hatch, causing adult 
populations to appear to move from pool to pool in a complex over time. 
The midvalley fairy shrimp does not typically occupy the same pools as 
other fairy shrimp species (Eriksen and Belk 1999). However, it is not 
clear to what extent listed shrimp may be expected to occupy the vernal 
pool complexes containing midvalley fairy shrimp. The CNDDB mentions 
the presence of listed vernal pool shrimp species (typically vernal 
pool fairy shrimp) at 16 of the 52 midvalley fairy shrimp occurrences. 
Fifteen of these are in the area of the proposed UC Merced campus, 
while the sixteenth is in a mitigation site in Sacramento County. We 
have no information at this time to indicate the Act would protect 
midvalley fairy shrimp in most of the other 36 occurrences.
    Additionally, Section 7 consultations require some form of Federal 
agency involvement, which for vernal pool species generally means a 
section 404 permit under the Clean Water Act. The recent ruling by the 
Supreme Court in Solid Waste Agency of Northern Cook County v. United 
States Corps of Engineers et al, 531 U.S. 159 (2001) (SWANCC) makes the 
application of the CWA to vernal pools (and, by extension, the 
protective power of section 7 of the Act) more tenuous. The Court in 
SWANCC determined that use of a water body by migratory waterfowl was 
insufficient in itself to establish that body as part of the ``waters 
of the United States'' subject to Federal jurisdiction. The Army Corps 
of Engineers (ACOE) of the Department of Defense and the Environmental 
Protection Agency (EPA) have issued an Advance Notice of Proposed 
Rulemaking (68 FR 1991) to address the question of which wetlands are 
still subject to the CWA. The notice indicates that field staff should 
address wetland jurisdiction on a case-by-case basis, and should avoid 
certain bases of jurisdiction altogether--i.e. where the sole basis for 
asserting CWA jurisdiction is the ``Migratory Bird Rule'' (51 FR 41206; 
November 13, 1986). It is not clear what this will mean for application 
of the CWA to vernal pools within the range of the midvalley fairy 
shrimp, although to date the ACOE has continued to assert jurisdiction 
over vernal pools in the area.
    The petition also argues that the Act would not adequately protect 
midvalley fairy shrimp even if they always co-occurred with listed 
species, because the smaller range of the midvalley shrimp leaves it 
comparatively more vulnerable to habitat loss. We do not expect this to 
be a factor, since we typically require specific vernal pool 
preservation and creation ratios as mitigation for any amount of listed 
vernal pool species habitat directly or indirectly affected by a 
project (Service 1999). Projects in the San Joaquin Valley, and those 
likely to affect more than a single acre of vernal pool habitat used by 
a listed species, are subject to individual review and further 
    The midvalley fairy shrimp's preference for shallower vernal pools 
than listed species could occasionally lead to disproportionate 
impacts, although we expect this to be rare. The range of average pond 
depths occupied by midvalley fairy shrimp (5 to 15 cm) is completely 
included within the range of average depths of pools occupied by both 
vernal pool fairy shrimp and vernal pool tadpole shrimp (2 to 122 cm 
and 2 to 151 cm, respectively) (Helm 1998). These two listed shrimps 
are also the most commonly occurring of the four listed species (CNDDB 
2002), and so are the most likely to determine modifications or 
mitigation measures for projects that also affect midvalley fairy 
shrimp. The other two listed species, longhorn fairy shrimp and 
Conservancy fairy shrimp, occupy pools with average depths in the upper 
half of the range of ponding depths used by the midvalley fairy shrimp 
(10 to 27 cm and 10 to 40 cm, respectively). Hence it is likely that 
reasonable and prudent alternatives determined for the protection of 
one of the listed shrimp species, such as the establishment of 
mitigation banks for vernal pool fairy shrimp, would also provide 
protected habitat for the midvalley fairy shrimp. It would be possible, 
however, for a project to avoid habitat preferred by a listed species 
in favor of habitat preferred by the midvalley fairy shrimp. The 
petition suggests such a situation applies to the proposed UC Merced 
campus in eastern Merced County (see below).
    The petition characterizes the UC Merced campus as a threat to the

[[Page 22726]]

species despite the known co-occurrence of listed shrimp species in the 
area. However, the petition was submitted prior to completion of a 
biological opinion for phase one of construction (BO or opinion) 
(Service 2002b). Although phase 1 construction as currently planned 
does not directly impact any vernal pools, the opinion recognizes the 
likely impacts further construction will have, and establishes a set of 
environmental parameters and conservation measures for the University 
to follow. These include preservation of extensive tracts of high 
quality vernal pool grasslands, judicious siting and design and use of 
best management practices. They also require the development of 
numerous conservation plans, including: A wetlands mitigation plan to 
prevent any net loss of wetlands functions or values; a compensation 
strategy for protected vernal pool crustaceans; a construction 
mitigation plan; and a project compensation plan to identify funding 
mechanisms for long-term management and monitoring of preserves. In 
addition to the required parameters and conservation measures, the 
opinion includes recommendations encouraging the university to evaluate 
and conserve species of concern, including the midvalley fairy shrimp. 
Although the university has already identified and secured 5,780 acres 
of land containing high quality vernal pool habitat for preservation, 
most of the conservation plans have not yet been completed.
    Under our policy for the evaluation of conservation efforts when 
making listing decisions (PECE policy), we must weigh both the 
certainty that conservation efforts will be implemented and the 
certainty that they will be effective in reducing the level of threat 
to the species. In this case the primary threat is loss of habitat, 
which the BO can potentially reduce in the vicinity of the proposed 
campus. Because many of the plans required by the BO are not yet 
completed and approved, however, the opinion as it now stands does not 
adequately identify the conservation effort, nor are the specifics 
approved by all parties. These points detract from the opinion's 
certainty of implementation under points A1 and A9 of the PECE policy. 
Additionally, the certainty of the opinion's effectiveness is reduced 
by the current lack of explicit incremental objectives and dates (point 
B2); as well as by the lack of specificity in some areas regarding the 
steps for achieving conservation goals (point B3), the parameters for 
determining progress (point B4), and the provisions for monitoring 
(point B5). Finally, since most of the enforceable conservation 
measures are established for the protection of listed species, it is 
not clear to what extent the midvalley fairy shrimp will benefit (point 
B1). The petition argues, for instance, that by moving the planned 
supporting community site to the southern end of the property in order 
to benefit listed shrimp the opinion will actually increase impacts to 
the midvalley fairy shrimp by concentrating construction in an area of 
shallow, low terrace vernal pools preferred by that species. 
Accordingly, the BO as it currently stands does not provide sufficient 
certainty that conservation efforts will be implemented nor that they 
will be effective in reducing the level of threat to the midvalley 
fairy shrimp.
    The petition also addresses the extent to which the CWA and the 
California Environmental Quality Act (CEQA) protect the midvalley fairy 
shrimp, concluding that in the absence of protected species or critical 
habitat neither statute is likely to prevent significant habitat loss. 
The CWA allows fill of up to 0.2 ha (0.5 ac) of wetlands without 
individualized permits, and does not require notification for many 
projects involving less than 0.04 ha (0.1 ac). Similarly, CEQA has not 
been implemented in such a way as to consistently require mitigation 
for vernal pool losses. We agree that these statutes fail to provide an 
adequate level of protection for the species.
    Finally, of the 52 known occurrences of the midvalley fairy shrimp, 
3 are in National Wildlife Refuges, 2 are in mitigation banks and 2 are 
in Nature Conservancy conservation easements (CNDDB 2002; Service in 
litt. 2003c) that may receive some portection. These seven occurrences 
are likely to receive increased local protection. Roughly 10 other 
occurrences are based on the survey we commissioned in 2001 that 
produced inaccurate and incomplete data. This leaves at least 35 
occurrences that are well documented but lack local protections. 
Eighteen of these 35 occurrences are on the proposed UC Merced campus, 
and 15 of those are known to co-occur with listed species. As discussed 
above, the protections provided for these occurrences are tenuous due 
to the uncertainty of continued ACOE assertion of jurisdiction over 
isolated vernal pools and the pending nature of the protections 
identified under the biological opinion for phase 1 of UC Merced 
construction. We therefore believe that existing regulatory mechanisms 
are not sufficient at this time to protect the species as a whole from 
the acknowledged habitat pressures discussed above.
    The petition also argues that because midvalley fairy shrimp 
populations tend to be small and isolated, they may suffer from 
inbreeding depression (decline of population fitness due to inbreeding) 
and from local extirpations, after which they are unable to recolonize. 
However, fairy shrimp cysts are ``passively dispersed with high 
probability by shore birds and other animals'' (Fugate 1998). Fugate 
(1998) goes on to note that under the most likely model, North American 
fairy shrimp species tend to become effectively isolated from each 
other at distances of 1,000 to 2,000 kilometers (km) (621 to 1,243 
miles (mi)). The farthest distance between midvalley fairy shrimp 
occurrences documented in the CNDDB (2002) is approximately 257 km (160 
mi). Naturally, local features will affect these generalized figures, 
and a population of shrimp in a vernal pool complex that has become too 
degraded may be in greater danger of genetic abnormalities or 
extirpation. However, the petition does not present such site-specific 
evidence, nor are we aware of any.

Emergency Listing

    The petition also requests us to list the midvalley fairy shrimp as 
endangered on an emergency basis. Under section 4(b)(7) of the Act, and 
regulations at 50 CFR 424.20, we may list a species on an emergency 
basis if the threats to the species constitute an emergency posing a 
significant risk to the well-being of the species. We believe the 
existing regulatory mechanisms discussed above are sufficient at this 
time to prevent the threat of habitat loss from constituting an 


    We have reviewed the petition, literature cited in the petition, 
other pertinent literature, and information available in Service files. 
We conclude the species may be threatened by habitat loss, and that 
existing regulatory mechanisms may not be sufficient to protect the 
species. Accordingly, we find the petition presents substantial 
information to indicate that listing the midvalley fairy shrimp may be 
    We have also reviewed the available information to determine if the 
existing and foreseeable threats pose an emergency. We have determined 
that an emergency listing is not warranted at this time.
    The petition also requests us to designate critical habitat for 
this species. We always consider the need for critical habitat 
designation when

[[Page 22727]]

listing species. If we determine in the 12-month finding determines 
that listing the midvalley fairy shrimp is warranted, we will address 
the designation of critical habitat in the subsequent proposed listing 

Public Information Solicited

    When we make a finding that substantial information exists to 
indicate that listing 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 information on 
the midvalley fairy shrimp. We request any additional information, 
comments, and suggestions from the public, other concerned governmental 
agencies, the scientific community, industry, or any other interested 
parties concerning the status of the midvalley fairy shrimp. We are 
seeking information regarding historic and current distribution, the 
species' biology and ecology, ongoing conservation measures for the 
species and its habitat, and threats to the species and its habitat.
    If you wish to comment, you may submit your comments and materials 
concerning this finding to the Field Supervisor (see ADDRESSES 
section). Our practice is to make comments, including names and home 
addresses of respondents, available for public review during regular 
business hours. Respondents may request that we withhold a respondent's 
identity, as allowable by law. If you wish us to withhold your name or 
address, you must state this request prominently at the beginning of 
your comment. However, we will not consider anonymous comments. To the 
extent consistent with applicable law, we will make all submissions 
from organizations or businesses, and from individuals identifying 
themselves as representatives or officials of organizations or 
businesses, available for public inspection in their entirety. Comments 
and materials received will be available form public inspection, by 
appointment, during normal business hours at the above address.

References Cited

Belk, D. and M. Fugate. 2000. Two new Branchinecta (Crustacea: 
Anostraca) from the Southwestern United States. Southwest Naturalist 
California Natural Diversity Data Base. 2002. California Department 
of Fish and Game, Natural Heritage Division. Sacramento, CA. 1 pp.
Eriksen, C. and D. Belk. 1999. Fairy shrimps of California's 
puddles, pools and playas. Mad River Press, Inc., Eureka, CA. 181 
Fugate, M.. 1998. Branchinecta of North America: population 
structure and its implications for conservation practice. Pages 140-
146 in C.W. Witham, E. Bauder, D. Belk, W. Ferren, and R. Ornduff, 
eds. Ecology, Conservation and Management of Vernal Pool Ecosystems. 
California Native Plant Society, Sacramento, CA.
Helm, B. 1998. Biogeography of eight large branchiopods endemic to 
California. Pages 124-139 in C.W. Witham, E.T. Bauder, D. Belk, W.R. 
Ferren Jr., and R. Ornduff, eds. Ecology, Conservation, and 
Management of Vernal Pool Ecosystems--Proceedings from a 1996 
Conference. California Native Plant Society, Sacramento, CA.
United States Fish and Wildlife Service. 1996. Interim survey 
guidelines to permittees for recovery permits under section 
10(a)(1)(A) of the Endangered Species Act for the listed vernal pool 
branchiopods. 10 pp. (Available at http://ventura.fws.gov/SurveyProt/shrimp.htm
United States Fish and Wildlife Service 1999. Programmatic formal 
endangered species act consultation on issuance of 404 permits for 
projects with relatively small effects on listed vernal pool 
crustaceans within the jurisdiction of the Sacramento Field Office, 
California. February 28, 1999. 13 pp.
United States Fish and Wildlife Service. 2002a. Critical habitat 
designation for four vernal pool crustaceans and eleven vernal pool 
plants in California and southern Oregon; proposed rule. 67 FR 
U.S. Fish and Wildlife Service. 2002b. Formal section 7 consultation 
on the University of California, Merced Campus and Infrastructure 
Project (199900203). Sacramento Fish and Wildlife Office, 
Sacramento, CA. 175 pp.
United States Fish and Wildlife Service. 2003. Policy for evaluation 
of conservation efforts when making listing decisions. 68 FR 15100.

In Litt. References

United States Fish and Wildlife Service. 2003a. Map of midvalley 
fairy shrimp occurrences, and occurrences of four other listed 
shrimp species, documented in CNDDB 2002.
United States Fish and Wildlife Service. 2003b. Endangered and 
threatened species that may occur in or be affected by projects in 
the selected quads listed below. (Species list generated from 
internal Service database).
United States Fish and Wildlife Service. 2003c. Electronic map of 
midvalley fairy shrimp occurrences from CNDDB 2002 overlaid on 
public lands as downloaded from the California Spatial Information 
Library (http://casil.ucdavis.edu/casil/legacy.ca.gov/govcon/).


    The primary author of this document is Glen Tarr (see ADDRESSES 


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

    Dated: April 18, 2003.
Steve Williams,
Director, Fish and Wildlife Service.
[FR Doc. 03-10310 Filed 4-28-03; 8:45 am]