Año Nuevo Island is a small island off Año Nuevo Point on the coast of Northern California, between San Francisco and Santa Cruz. The island has an area of 9 acres (3.6 ha). It is an important breeding site for northern elephant seals and the endangered Steller's sea lion, as well as several species of seabirds, including rhinoceros auklets, Brandt's cormorants and western gulls. Due to the number of seals and sea lions, great white sharks are frequently spotted patrolling the waters around the island. It is protected as part of the Año Nuevo State Reserve.

The Steller sea lion is a large, near-threatened species of sea lion, predominantly found in the coastal marine habitats of the northeast Pacific Ocean and the Pacific Northwest regions of North America, from north-central California to Oregon, Washington and British Columbia to Alaska. Its range continues across the Northern Pacific and the Aleutian Islands, all the way to Kamchatka, Magadan Oblast, and the Sea of Okhotsk, south to Honshu's northern coastline. It is the sole member of the genus Eumetopias, and the largest of the so-called eared seals (Otariidae). Among pinnipeds, only the walrus and the two species of elephant seal are bigger. The species is named for the naturalist and explorer Georg Wilhelm Steller, who first described them in 1741. Steller sea lions have attracted considerable attention in recent decades, both from scientists and the general public, due to significant declines in their numbers over an extensive portion of their northern range, notably in Alaska.