SEA OTTER FORAGING ON PISMO BEACH: INTERACTIONS BETWEEN SOUTHERN SEA OTTERS AND PISMO CLAMS

 

Isa M Mattioli; Cal Poly SLO; imattiol@calpoly.edu; Marissa Bills, Benjamin I. Ruttenberg

Pismo clam (Tivela stultorum) populations were previously abundant on the California central coast before declining dramatically in the late 1970s and 1980s. However, recently their population has been increasing. The southern sea otter (Enhydra lutris nereis) was hunted to near extinction in the 1800s, leading to a dramatic reduction of their range, including their extirpation from Pismo Beach. Their population has since been recovering, and they are repopulating historic range locations including Pismo Beach in the 1970s, which coincided with the decline in clam populations locally. Since sea otters are an important predator of Pismo clams, we sought to explore the potential impact of sea otter predation on Pismo clam population abundance and recovery by conducting otter foraging surveys on three local beaches. Our preliminary results found that sea otters are commonly seen at the north-most end of Pismo State Beach, and their diet consists of primarily Pismo clams. This data will help illuminate the impact of sea otter predation on Pismo clam populations, and we hope it can help inform management practices to support both species’ recoveries on the Central Coast.

Poster Session   Student Paper