The National Marine Mammal Laboratories' California Current Ecosystem Program (AFSC/NOAA) initiated a long-term marking program of northern fur seals (Callorhinus ursinus) at San Miguel Island, California in 1975. A sample of up to 300 pups has been tagged in the foreflippers with various types and colors of tags each year between 1975 and the present. Resighting surveys for marked animals are conducted annually at summer breeding sites. Resightings are also obtained from the public when animals are observed on beaches or in fisheries. The data are used in mark-recapture models to estimate the age and sex specific vital parameters of the population and to describe age and sex specific reproductive behavior and seasonal movements of animals throughout their lives.

The Marine Mammal Laboratories' California Current Ecosystem Program (AFSC/NOAA) in collaboration with Point Blue Conservation Science initiated long-term studies to determine pup abundance of the California Stock of northern fur seals. The California Stock is comprised of northern fur seals inhabiting San Miguel Island (and Castle Rock, and islet ~1 km northwest) and the Farallon Islands (specifically, Southeast Island) off California. Pup production is the sum of the numbers of live pups and dead pups for a given pupping season. This in turn is used as index to estimate total population abundance. Population abundance is vital to knowing the status of a particular stock or the entire species, as well as knowing what factors are driving population trends. Metadata and datasets corresponding to these studies are reported in Stock Assessment Reports (SAR) for the U.S. Congress and other stakeholders.

This dataset contains data from the capture and recapture of over 1500 male California sea lions (Zalophus californianus) from Washington between 1989-2006. The data fields include capture data such as time, location, weight, length, and girth for each animal captured. The dataset also includes records of resights of each animal from records collected from observers from California to Vancouver Island, British Columbia, Canada. The dataset also contains information from opportunistic captures of Steller sea lions (Eumetopias jubatus) in the same region.