California sea otter (Enhydra lutris nereis) census results, Spring 2016

Data Series 1018
By:  and 

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Abstract

The 2016 census of southern sea otters Enhydra lutris nereis was conducted in May along the mainland coast of central California and in April at San Nicolas Island in southern California. The 3-year average of combined counts from the mainland range and San Nicolas Island was 3,272. This is the first year that the official index has exceeded 3,090, the Endangered Species Act delisting threshold suggested by the U.S. Fish and Wildlife Service (the threshold would need to be exceeded for 3 consecutive years before delisting consideration). The 5-year average trend in abundance, including both the mainland range and San Nicolas Island populations, is positive at 3.2 percent per year; however, regional trends vary, with localized declines at the southern and northern peripheries of the mainland range. The lack of population growth in the range peripheries over recent years likely explains the cessation of range expansion, with the range limits remaining almost unchanged from the previous 5 years.

Suggested Citation

Tinker, M.T., and Hatfield, B.B., 2016, California sea otter (Enhydra lutris nereis) census results, spring 2016: U.S. Geological Survey Data Series 1018, 10 p., http://dx.doi.org/10.3133/ds1018.

ISSN: 2327-638X (online)

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Table of Contents

  • Abstract
  • Introduction
  • California Sea Otter Census Results
  • Acknowledgments
  • References Cited

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title California sea otter (Enhydra lutris nereis) census results, Spring 2016
Series title Data Series
Series number 1018
DOI 10.3133/ds1018
Year Published 2016
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Western Ecological Research Center
Description Report: iv, 9 p.; Data Release
Country United States
State California
Online Only (Y/N) Y