Population regulationof the purple sea urchin, Strongylocentrotus purpuratus, at the California Channel Islands
Kushner D and Lafferty KD. 2000. Population regulationof the purple sea urchin, Strongylocentrotus purpuratus, at the California Channel Islands. Proceedings of the Fifth California Islands Symposium. :379-981
We studied purple urchin populations at the Channel Islands National Park at 16 sites from 1992 to 1998 to better understand factors associated with the abundance and distribution of this important grazer. Recruitment did not explain variation in adult abundance. Urchin abundance increased as invertebrate predators (sunflower stars and spiny lobsters) decreased. High urchin densities were subject to bacterial disease that impacted urchin abundance in a density dependent fashion. Eastern sites typically had lower predator abundance, higher urchin abundance, and more frequent disease dynamics than western sites. An exception to this geographic pattern was a marine protected area at Anacapa Island with a high density of lobsters, a low density of urchins and a near absence of disease.
- Type
- Journal Article
- Authors
- Kushner, D.; Lafferty, K.
- Units
- CHIS
- Keywords
- bacteria, disease, lobsters, predation, recruitment, Strongylocentrotus, Urchins