Category: Status Reports
Published: April 2021
Author(s): Jessica J Stocking and Gary J. Wiles
The Steller sea lion (Eumetopias jubatus) was delisted from state threatened status in 2015. This document reviews the post-delisting status of the Steller sea lion in Washington, as required in WAC 220-610-110.
Steller sea lions are dietary generalists that prey on a broad variety of fish and cephalopods, including both benthic and pelagic species. They move long distances to track abundant prey, resulting in patchy seasonal distributions. Haulouts for resting and rookeries for breeding and pupping are typically located on islands and offshore rocks and often used year after year. Many adult females do not breed annually, resulting in lower productivity than most other pinnipeds.
Steller sea lions in Washington belong to the eastern distinct population segment (DPS), one of two DPSs comprising the species. The eastern DPS ranges along the west coast of North America from Southeast Alaska to central California (i.e., east of 144°W longitude) and has been steadily increasing in Washington and range-wide. From 1987 to 2017, models from non-pup counts and pup counts in the eastern DPS increased at average annual rates of 3.22% and 4.25%, respectively, with the overall population growing from an estimated 18,313 animals in 1979 to at least 71,562 animals in 2019. Steller sea lion abundance in Washington has also grown, with numbers of non-pups at four sites surveyed during summer increasing at an average rate of 9.12% from 1987-2017 and year-round surveys during 2010-2018 estimating a 7.9% increase. Small but increasing numbers of pups have been born at several sites since 1992, with a recently established rookery complex producing more than 200 pups in 2020.
Steller sea lions experience several stressors associated with climate change effects and anthropogenic activities. Recently, increasing numbers of Steller sea lions have travelled up the Columbia River to forage on prey concentrated at the Bonneville Dam. This shift has resulted in a request to NOAA Fisheries by state and tribal managers for authority to lethally remove animals at the dam to protect imperiled salmon stocks. Based on sustained population growth and the lack of significant threats, it seems likely that Steller sea lion numbers in Washington will continue to increase for the foreseeable future; it is recommended that the species retain its status as a delisted species in Washington.
Stocking, J. J, and G. J. Wiles. 2021. Draft periodic status review for the Steller Sea Lion in Washington. Washington Department of Fish and Wildlife, Olympia, Washington. 14+iii pp.