Vernal Pool Fairy Shrimp (Branchinecta lynchi) 5-Year Review: Summary and Evaluation Copyright: Larry Serpa U.S. Fish and Wildlife Service Sacramento Fish and Wildlife Office Sacramento, California September 2007 1 Oregon Idaho 5 101 80 Carson City Nevada Sacramento San Francisco Oakland San Jose Fresno Las Vegas 101 99 15 5 40 Los Angeles ESA Five Year Review Santa Ana 10 Vernal Pool Fairy Shrimp Long Beach Branchinecta lynchi San Diego CNDDB occurences 037.5 75 150 Miles SFWO GIS Branch 5/2007 1 5-YEAR REVIEW Vernal Pool Fairy Shrimp (Branchinecta lynchi) I. GENERAL INFORMATION I.A. Methodology used to complete the review: This review was an individual effort by Sacramento Fish and Wildlife Office staff using information from the following sources: the December 2005 Recovery Plan for Vernal Pool Ecosystems of California and Southern Oregon (Recovery Plan) (U.S. Fish and Wildlife Service [Service] 2005); the September 1999 Vernal Pools of Southern California Recovery Plan (Service 1998); the June 2006 Draft Recovery Plan for Species of the Rogue Valley Vernal Pool and Illinois Valley Wet Meadow Ecosystems (Service 2006a); species survey and monitoring reports; peer-reviewed journal articles; documents generated as part of Endangered Species Act section 7 and section 10 consultations; and species experts including botanists, biologists, and land-managers from the U.S. Forest Service, California Department of Fish and Game (CDFG), and the Service. We also considered information from a Service-contracted report. The Recovery Plan, section 7 consultations, electronic messages from the Service’s Carlsbad and Ventura Fish and Wildlife Offices, and communications with species experts and land-managers were the primary sources of information used to update the “species status” and “threats” sections of this review. I.B. Contacts Lead Regional or Headquarters Office – Diane Elam, Deputy Division Chief for Listing, Recovery, and Habitat Conservation Planning, and Jenness McBride, Fish and Wildlife Biologist, California/Nevada Operations Office, 916-414-6464 Lead Field Office – Kirsten Tarp, Recovery Branch, Sacramento Fish and Wildlife Office, 916-414-6600. Cooperating Field Offices –Ventura and Carlsbad, California, and Roseburg, Oregon I.C. Background I.C.1. FR Notice citations announcing initiation of this review: On March 22, 2006, the Service announced initiation of the 5-year review for the vernal pool fairy shrimp and asked for information from the public regarding the species’ status (71 FR 14538). On April 3, 2006, a corrected announcement was issued to correct contact information for Service field offices (71 FR 16584). In response to this notice, we received information providing status of known vernal pool fairy shrimp locations at Fort Hunter Liggett Army Reserve Training Site in southern Monterey County and negative survey findings for Camp Parks Reserve Training Site in Contra Costa and Alameda counties (L. Clark, U.S. Army, in litt. 2006). 2 I.C.2. Listing history Original Listing FR notice: 59 FR 48136 Date listed: September 19, 1994 Entity listed: Species, vernal pool fairy shrimp (Branchinecta lynchi) Classification: Threatened I.C.3. Associated rulemakings: Critical Habitat Listed: Critical habitat for the vernal pool fairy shrimp was originally designated in a final rule published in 68 FR 46683 on August 6, 2003. A revised final rule for critical habitat, with a re-evaluation of non-economic exclusions, was published in 70 FR 11140 on March 8, 2005. Economic exclusions from the 2003 final rule were evaluated in 70 FR 46923; published on August 11, 2005. Administrative revisions with species-by-unit designations were published in 71 FR 7117 on February 10, 2006, providing 35 critical habitat units for the vernal pool fairy shrimp totaling 597,821 acres. On May 31, 2007, the Service published a clarification of the economic and non-economic exclusions for the 2005 final rule designating critical habitat for four vernal pool crustaceans and eleven vernal pool plants in California and southern Oregon (72 FR 30269). I.C.4. Review History 90-Day finding: A 90-day finding on a petition to delist the vernal pool fairy shrimp and vernal pool tadpole shrimp was published in 65 FR 18026 on April 6, 2000. The finding determined that the petition and additional information did not present substantial scientific or commercial information indicating that delisting the vernal pool fairy shrimp was warranted. I.C.5. Species’ Recovery Priority Number at start of review: The vernal pool fairy shrimp has a recovery priority number of 2C (based on a 1-18 ranking system where 1 indicates the highest recovery priority and 18 the lowest priority), which signifies that the species is subject to a high degree of threat, but also has a high potential for recovery. The “C” indicates the potential for conflict between species recovery and construction activities, development, or other economic activities (Service 2005 Recovery Datacall). I.C.6. Recovery Plan or Outline Name of plan: Recovery Plan for Vernal Pool Ecosystems of California and Southern Oregon Date issued: December 15, 2005 The Recovery Plan for Vernal Pool Ecosystems of California and Southern Oregon is the only recovery plan that provides recovery criteria for the vernal pool fairy shrimp; however, two other recovery plans do provide information pertaining to the shrimp. The Draft Recovery Plan for Listed Species of the Rogue Valley Vernal Pool and Illinois Valley Wet Meadow Systems (Service 2006a) provides recovery actions specific to the Oregon range of the vernal pool fairy shrimp. The recovery actions in the draft recovery plan for Oregon occurrences respond to the recovery criteria identified in the broader Recovery Plan for Vernal Pool Ecosystems of California and Southern Oregon (Service 2005a) by providing site-specific recovery actions for 3 the shrimp within the Klamath Mountains Recovery Unit; they are not, however, “recovery criteria” required to delist the species. The Recovery Plan for Vernal Pools of Southern California (Service 1998) provides recovery guidance for several areas in which vernal pool fairy shrimp are located in Los Angeles and Riverside Counties, to the extent that the species co- occurs with the endangered Riverside fairy shrimp (Streptocephalus woottoni). II. REVIEW ANALYSIS Species Overview The vernal pool fairy shrimp (Branchinecta lynchi) is a small freshwater crustacean (0.12 to 1.5 inches long) belonging to an ancient order of branchiopods, the Anostraca. Like other anostracans, it has stalked compound eyes and eleven pairs of phyllopods (swimming legs that also function as gills). The vernal pool fairy shrimp is genetically distinct from other Branchinecta species, and is distinguished by the morphology of the male’s second antenna and the female’s third thoracic segment (on the middle part of its body) (Belk and Fugate 2000, as cited in Service 2005a). The species was first collected between 1874 and 1941, when it was described incorrectly as Branchinecta colorodensis (Linder 1941 in Service 2005a). Its identity as a separate species was resolved only in 1990 (Eng et al. 1990). Subsequent genetic analysis has confirmed that the vernal pool fairy shrimp is a distinct species (Fugate 1992). The vernal pool fairy shrimp is endemic to California and the Agate Desert of southern Oregon. It has the widest geographic range of the federally-listed vernal pool crustaceans, but it is seldom abundant where found, especially where it co-occurs with other species (Eng et al. 1990; Eriksen and Belk 1999). The vernal pool fairy shrimp has an ephemeral life cycle and exists only in vernal pools or vernal pool-like habitats; the species does not occur in riverine, marine, or other permanent bodies of water. Roughly 80 percent of observations of the shrimp are from vernal pools (Helm 1998; Helm and Vollmar 2002). Like most other fairy shrimps, the vernal pool fairy shrimp lacks any substantial anti-predator defenses and does not persist in waters with fish (King et al. 1996; Eriksen and Belk 1999). When the temporary pools dry, offspring persist in suspended development as desiccation-resistant embryos (commonly called cysts) in the pool substrate until the return of winter rains and appropriate temperatures allow some of the cysts to hatch (Eriksen and Belk 1999). Vernal pool habitats form in depressions above an impervious substrate layer, or claypan/duripan, in alluvial fans and terraces that are known primarily from the eastern side of the Central Valley of California (Vollmar 2002). Due to local topography and geology, the depressions are part of an undulating landscape, where soil mounds are interspersed with basins, swales, and drainages. Both flooding and the movement of wildlife within vernal pool complexes allow fairy shrimp to disperse between individual pools. These movement patterns, as well as genetic evidence, indicate that vernal pool fairy shrimp populations are defined by entire vernal pool complexes, rather than individual pools (King et al. 1996; Fugate 1998). The vernal pool fairy shrimp occurs only in cool-water pools. Individuals hatch from cysts during cold-weather winter storms; they require water temperatures of 50oF or lower to hatch (Helm 1998; Eriksen and Belk 1999). The time to maturity and reproduction is temperature- dependent, varying between 18 days and 147 days, with a mean of 39.7 days (Helm 1998). 4 Immature and adult shrimp are known to die off when water temperatures rise to approximately 75oF (Helm 1998). The range of the species extends from disjunct locations in Riverside County and the Coast Ranges, north through Central Valley grasslands to Tehama County, and then to a disjunct area of remnant vernal pool habitat in the Agate Desert of Oregon. In general, the vernal pool fairy shrimp has a sporadic distribution within the vernal pool complexes, with most pools being uninhabited by the species (59 FR 48136). Helm (1998) found vernal pool fairy shrimp in 16.3 percent of pools sampled across 27 counties, while Sugnet and Associates, in 1993, found the species in 5 percent of 3,092 locations sampled over much of the range (Service 2005a).