2015 Census Summary Shapefile

Publication Date

2015

Tinker, M.T., and Hatfield, B.B., 2015, Southwest U.S. Southern sea otter annual range-wide census results: U.S. Geological Survey data release, http://dx.doi.org/10.5066/F7F47M5C.

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 U.S. Fish and Wildlife Service as a primary basis for management decisions (including de-listing or up-listing decisions) for this sub-species, which is listed as "Threatened" under the U.S. Endangered Species Act.

ScienceBase WMS

ScienceBase WFS

• USGS Western Ecological Research Center

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