Steller sea lions range along the North Pacific Rim from northern Japan to California. Pupping and breeding occur late May to early July throughout their range. Males set up territories on rookeries in late May, females arrive shortly thereafter and give birth to a single pup. They alternate between nursing their pup and feeding trips; most pups are weaned by the end of their first year. The species is not known to migrate, but individuals disperse widely outside of the breeding season, particularly adult males and juveniles. Adult males are up to 3.25 m long and weigh up to 1120 kg; females are considerably smaller at up to 2.9 m and 350 kg. Pups weigh about 23 kg at birth. Two separate stocks of Steller sea lions are recognized within U. S. waters: an eastern and western stock. As a result of a precipitous decline in numbers beginning in the 1970s, the western stock is presently listed as Endangered under the ESA.
Dr. Tom Gelatt explains how NOAA Fisheries scientists are working to
protect and study threatened Steller sea lions.
- Population Decline
- Steller sea lion research coordination, 2007, 2008, 2009, 2010, 2011
- Steller sea lion surveys 2008, 2009, 2010, 2011, 2012,, 2013, NEW - 2014
- Steller sea lion databases
- Employing Technology for Conservation
- Telemetry Research
- Current Research Projects by the Alaska Ecosystems Program
- Current Research Projects by the California Current Ecosystems Program
- Publications: search AFSC database for Steller Sea Lions
- Posters: search AFSC database for Steller Sea Lions
- Quarterly Reports
- FRITZ, L. W., R. TOWELL, T. S. GELATT, D. S. JOHNSON, and T. R. LOUGHLIN.
2014. Recent increases in survival of western Steller sea lions in Alaska and implications for recovery. Endang. Species Res. 26:13-24. (.pdf, 1.11 MB). Online.
- McCLINTOCK, B. T., J. M. HILL, L. FRITZ, K. CHUMBLEY, K. LUXA, and D. R. DIEFENBACH.
2014. Mark-resight abundance estimation under incomplete identification of marked individuals. Methods Ecol. Evol. 5:1294-1304.
- JOHNSON, D. S., and L. FRITZ.
2014. agTrend: a Bayesian approach for estimating trends of aggregated abundance. Methods Ecol. Evol. 5:1110-1115.
- O'CORRY-CROWE, G., T. GELATT, L. REA, C. BONIN, and M. REHBERG.
2014. Crossing to safety: Dispersal, colonization and mate choice in evolutionarily distinct populations of Steller sea lions, Eumetopias jubatus. Mol. Ecol. 23:5415-5434.
- Search the AFSC database for additional Steller Sea Lion publications
- Steller Sea Lion Diet and Population Trends in the Aleutian Islands
n-011, n-042, n-017 Online.
- Steller Sea Lion Decline at Medny Island Rookery, Russia, in Summer 2013
2.84 MB Online.
- Apparent Age of First Reproduction in Steller Sea Lions on Russian Rookeries
3.16 MB Online.
- Search the AFSC database for additional Steller Sea Lion posters