Steller Sea Lion Research Projects

Our program supports recovery of Steller sea lions in Alaska through extensive field and laboratory research. Learn about our studies designed to understand the factors impeding recovery of the western population of Steller sea lions, and then compare them to our studies of the eastern population that continues to increase.

Studying sea lions requires specialized techniques because they spend much of their lives underwater and rest on remote haulouts and rookeries. Learn how we collect and analyze data to monitor the survival and reproductive rates that drive sea lion population change, investigate sea lion health, explain the seasonal, geographic and age-specific patterns of sea lion foraging and determine at what age sea lions wean to become independent foragers. We also work to photo-document and reduce sea lion entanglement in marine debris. We collaborate with multiple outside organizations to ensure the samples we collect are used for maximum benefit to sea lion recovery.

  • Steller Sea Lion Entanglements
    “Lose the loop!” We study sea lion entanglements in marine debris and produced a video on how to reduce these injuries and mortalities.
  • Population Vital Rates
    Our program conducts intensive mark-resight field work and analysis to learn the individual survival and reproductive rates that drive sea lion population change. Learn how to report your sightings of marked sea lions!
  • Live-Capturing Sea Lions
    Our program studies free-ranging sea lions in their natural habitats. Here is how we catch them.
  • Diet and Foraging
  • Foraging Ontogeny
    We examined the roles of physiological development, nutritional source and demand for independent foraging in development of behavior by young-of-year sea lion pups by conducting the first successful targeted capture/recapture project on this species.
  • Reproduction
  • Stress-related Hormones
  • Contaminants
  • Body Condition Analysis
    We measure, sample and test sea lions to understand whether individual sea lions are fasting, starving, undernourished or well-fed and healthy, and we look for seasonal and regional trends in these measures. Much of this work is done by our in-house laboratory and through collaboration with outside agencies.
  • Glacier Bay Genetics and Movement
    The Icy Strait region is an interesting mixing ground for sea lions from the endangered western population and increasing eastern population. We captured sea lions here during November 2009 to better understand this unique region and its contribution to sea lion populations.
  • Sea Lion Tracking Projects
    We track the behavior free-ranging sea lions using instruments that report movements, diving and other parameters to answer questions about swimming and diving ability and understand their responses to season, light and other environmental factors.
  • Monitoring Remote Bering Sea Locations
    We have begun making sea lion counts and mark-resight field work in the northern Bering Sea, a region in which counts and resights have not previously been made on an annual basis. A cooperative project with the community of Gambell.

Contact the ADF&G Steller Sea Lion Program at