Status and Ecology of Sensitive Aquatic Vertebrates in Lower San Simeon and Pico Creeks, San Luis Obispo County, California

摘要

The report includes visual surveys during 1992 in San Simeon and Pico Creeks in coastal San Luis Obispo County, California. The authors objectives were to determine the status, habitats and relative abundance of five sensitive, aquatic species: the tidewater goby (Eucyclogobius newberryi), steelhead rainbow trout (Oncorhynchus mykiss), California red-legged frog (Rana aurora), southwestern pond turtle (Clemmys marmorata), and two-striped garter snake (Thamnophis hammondii). They also monitored water depths, flows, salinities, temperatures, and various water chemistry parameters. With the exception of steelhead, the sensitive taxa are relatively abundant in both creeks. All five species require similar aquatic habitats, including deep pools and vegetative cover. Riparian areas, as well as upland grassland and chaparral habitats, are used by the turtle and snake for nesting and sheltering, and well-vegetated terrestrial areas within the riparian corridor provide important sheltering habitat for the frog. A natural regime of water flow is probably important in maintaining salinities within the tolerances of the five native species, and in controlling introduced aquatic predators.