Año Nuevo Island Reserve

Año Nuevo Island Reserve
Weaned elephant seal pups. Photo by Kathleen M. Wong

Located midway between San Francisco and Santa Cruz, along the rural San Mateo coast, Año Nuevo Island is a rocky islet teeming with with breeding seals, sea lions, and seabirds. Just two hundred years ago the island was connected to the mainland by a low peninsula. It served as a Coast Guard light station from 1872 to 1948. The fog signal house and abandoned former lightkeepers’ residence can still be seen from shore. Today the island is part of 4,000-acre Año Nuevo State Reserve, which is owned and operated by California State Parks. Access to the island is limited to scientific researchers.

Año Nuevo Island is an important breeding ground for northern elephant seals, threatened Steller sea lions, and smaller numbers of harbor seals. It is a major haulout area for California sea lions. Threatened southern sea otters and great white sharks frequent the nearshore waters. The reserve supports a 40-year ongoing study of the growing elephant seal population, which has rebounded from near extinction a century ago. The study has expanded to investigate questions about the diving abilities of elephant seals and the physiology that supports dives to depths in excess of a kilometer for over an hour. The scientists also track the twice-yearly migrations of the seals which range as far as Alaska and Hawaii, and return to Año Nuevo to fast ashore for one to three months without food or water.

The island also supports nesting colonies of sea birds, including Brandt’s cormorants, western gulls, pelagic cormorants, rhinoceros auklets, pigeon guillemots, Cassin’s auklets, and black oystercatchers. There are very few places on earth with higher densities of large animals.

Researchers are accommodated in the historic buildings of the former Coast Guard light station. Due to the highly sensitive habitats and protected marine mammals and seabirds on the island, reserve use is restricted to scientific research. Researchers should contact the manager before submitting an application.

Public Tours

The California Department of Parks and Recreation coordinates limited guided tours of elephant seal breeding grounds on the mainland. Visitor information and tour reservations are available at the Año Nuevo State Park website.

Selected Research

  • Northern elephant seals: effects of low-frequency sound in the marine acoustic environment; geographic-reference behavior during migrations; buoyancy and swimming effort; predator-prey relationships with white sharks; and developmental physiology of pups during natural, prolonged fasts.
  • Population monitoring of Steller sea lions.
  • Conservation, demography, and food habits of rhinoceros auklets. A project enhances and restores the rhinoceros auklet population using nest boxes and ongoing monitoring.

Patrick Robinson
Long Marine Laboratory
100 Shaffer Road Santa Cruz, CA 95060
Año Nuevo Island Reserve website

Public access to the island is not permitted, but tours of the mainland elephant seal colony are administered by California State Parks.

San Mateo County, near the Santa Cruz County line; 1 km (0.62 mi.) offshore of Point Año Nuevo. Part of Año Nuevo State Reserve, the island is owned by the California Department of Parks and Recreation.

Historic buildings provide limited dormitory, kitchen, and field lab space; electricity provided by diesel generator; no running water; observation blinds serve major pinniped areas.

The reserve bibliography includes citations of journal articles, books, theses, art, and other works published about or based on activities conducted at the reserve.

Plant List
Pinniped records continuous since 1967. Census data for all pinniped species present on the island (northern elephant seals, Steller’s sea lions, California sea lions and harbor seals). Re-sighting and breeding records for individually tagged Northern elephant seals. Shorter term records for breeding seabirds (especially rhinoceros auklets) are maintained by Point Blue and Oikonos. The National Marine Mammal Lab maintains re-sighting records for individually marked California sea lions present during the summer since 1996; extensive bibliography of published research
INaturalist Project

Reserve manager on campus; no on-site personnel.

10 hectares (25 acres), including the area of small rocky islets and coves immediately adjacent to the main island.

0 to 13 m (0 to 40 ft.

50 cm (20 in.) per year

September maximum: 24 ºC (76 ºF)
January minimum: 4 ºC (39 ºF)
Annual mean: 13 ºC (56 ºF)

reviving field research
Graduate researcher Caroline Casey records the vocalizations of an adult male elephant seal at Año Nuevo Island Reserve. Permits NMFS-19108, MBNMS-2017-018)