Abundance of pup and non-pup Steller sea lions at Año Nuevo Island, 1990-2004, based on counts in July. Both pup and non-pup population sizes declined over the survey period. Mark Lowry, via www.sanctuarysimon.org

The decline of the central California breeding population cannot be attributed solely to any single threat listed below, but instead is the result of a combination of multiple threats. In some cases, exposure to one threat may make the animals more susceptible to the others (e.g., high level of contaminants may make an animal more susceptible to disease). The relative importance of many of these threats is not known.

SPECIAL STATUS SPECIES: STELLER SEA LION (Eumetopias jubatus)