One vernal pool complex in Orange County was also excluded from the final designation because new information indicated the pool had been removed during construction of the San Antonio Parkway. These vernal pool complexes are essential to the conservation of the Riverside fairy shrimp and are included in the critical habitat designation. Although the Service is designating 6,870 acres as critical habitat for the fairy shrimp, not all the areas within those broad boundaries contain the primary constituent elements to support the species. When mapping each of the critical habitat units, Service biologists attempted to exclude developed areas such as roads, buildings and agricultural fields because these areas do not support habitat for the Riverside fairy shrimp. However, they were unable to exclude all developed areas from the critical habitat designation.
Vernal pools are seasonal wetlands that fill with water during fall and winter rains.
They are home to many plants and animals that, in turn, form a valuable part of the food chain for a wide array of animals, including birds of prey, shorebirds, migratory waterfowl, frogs, toads, salamanders and pollinating insects. Once abundant throughout most of the Central Valley and coastal areas of southern California, vernal pools have declined significantly as a result of urban development and agricultural conversion, alterations of vernal pool hydrology, off-road vehicle activity, livestock overgrazing and other activities. Riverside fairy shrimp have a red-colored tail and are approximately 0.5 to 1 inch in length. Female fairy shrimp have a brood pouch extending along the abdomen. The species has a short life cycle, hatching and maturing within 7 to 14 days, depending on water temperature.