CO0052918 - Laserfiche WebLink

Home Browse Search

Soil Investigations for Data Collection in the Delta Initial Study/Proposed Mitigated Negative Declaration 77 conditions render the habitat unsuitable. Cysts are shed by mated females and remain in the soil until the following winter (USFWS 2017a). Conservancy fairy shrimp require an average of 49 days to reach maturity and are known to survive in temperatures ranging from 41 to 75 degrees Fahrenheit (Eriksen and Belk, 1999). Conservancy fairy shrimp has moderate potential to occur within the Study Area based on the presence of suitable habitat. Implementation of Mitigation Measures MM BIO-1 and MM BIO-12 would avoid and minimize adverse impacts to suitable habitat and would reduce potential impacts to Conservancy fairy shrimp to: Less than Significant with Mitigation Incorporated. MM BIO-12: Vernal Pool Species a. All ground disturbing activities (boring, CPT, or vegetation removal) shall be located at least 100 feet from a vernal pool to avoid impacts to sensitive vernal pool invertebrates. b. No project activities shall take place within an area identified as vernal pool complex, as determined by a qualified biologist, when wet soil conditions would increase the likelihood of vehicle traffic or other activities altering the site topography. Longhorn fairy shrimp (Branchinecta longiantenna) Longhorn fairy shrimp is listed as Endangered under FESA but is not listed under CESA. It has a NatureServe ranking of G2S2 and is included on CDFW’s Special Animals List. This species is a 1.3 to 2 cm short-lived aquatic crustacean found in ephemeral freshwater habitats. It is endemic to California, and its known range is limited to four areas within and adjacent to the following locations: Carrizo Plain National Monument in San Luis Obispo County, San Luis National Wildlife Refuge Complex in Merced County, Brushy Peak Preserve in Alameda County, and Vasco Caves Preserve in Contra Costa County (USFWS 2007b). Longhorn fairy shrimp are found in vernal pools which may be clear or turbid. They have been found in clearwater depressions in sandstone outcroppings, grass-bottomed pools, and claypan pools. Like other fairy shrimp, longhorn fairy shrimp hatch from desiccated cysts that remain in the soil until the first winter rains and complete their lifecycle by early summer. Cysts are shed by mated females and remain in the soil until the following winter (USFWS 2017b). Longhorn fairy shrimp mature in approximately 43 days and are known to survive in temperatures ranging from 50 to 82 degrees Fahrenheit (Erickson and Belk 1999). Longhorn fairy shrimp has moderate potential to occur within the Study Area based on the presence of suitable habitat. Implementation of Mitigation Measures MM BIO-1 and MM BIO-12 would avoid and minimize adverse impacts