Annual California Sea Otter Census: 2018 Census Summary Shapefile

Publication Date

2018-09-24

Start Date

2018-04-26

End Date

2018-05-24

Hatfield, B.B., Yee, J.L., Kenner, M.C., Tomoleoni, J.A., and Tinker, M.T., 2018, Annual California sea otter census—2018 spring census summary: U.S. Geological Survey data release, https://doi.org/10.5066/P98012HE.

The range-wide census is conducted to monitor trends in abundance of the southern sea otter, and thus provide State and Federal resource agencies with the information they need for effective management. Because the censuses represent uncorrected total counts (rather than sample-based surveys), they cannot be considered as accurate estimates of true population abundance. Instead, these data represent a valuable time-series of index counts, and provide the means of assessing spatial and temporal trends in relative abundance. The 3-year running average of the spring counts have been identified as the best index of trends and status of the population, because these averages decrease the influence of year-to-year sampling variance. The 3-year average counts are used by the US Fish and Wildlife Service in its listing determinations (de-listing or up-listing) for this legally threatened population.

ScienceBase WMS

ScienceBase WFS

• USGS Western Ecological Research Center

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