Since May 1997, the volunteers of the Coastal Ocean Mammal and Bird Education and Research Surveys (BeachCOMBERS) have conducted systematic surveys in the Monterey Bay National Marine Sanctuary. The main goal of the program was to determine human and natural impacts to the Monterey Bay ecosystem. Marine birds and mammals are conspicuous top predators of the marine ecosystem, and the deposition of these dead organisms on beaches was used as an indicator of marine ecosystem health, including availability of prey resources, anthropogenic impacts, and natural die-offs.