Since 1982, a standardized method has been
deployed to survey the sea otter population in California. The entire sea otter range is surveyed twice
annually, in early fall and late spring. The spring surveys have traditionally been
used to assess population status because they are both consistently higher than
fall surveys and show less variability.The fall survey data supplements the spring data to provide the
necessary information to assess female reproductive rates and changes in
reproductive success of the California sea otter population through time.