Distribution and abundance of Steller sea lions (Eumetopias jubatus) in Oregon, July 2025, Science Bulletin 2026-01

Identification Information

Citation

Originator: Bryan E. Wright and Susan D. Riemer

Publish Date: January 14, 2026

Online Link: None

BPA Project #:

Contact Information

Agency: Oregon Department of Fish and Wildlife

Name: Bryan Wright

Job Position: Biometrician, Marine Mammal Program

Telephone: 541-760-9543

E-Mail Address: Bryan.E.Wright@odfw.oregon.gov

Description

Abstract: The Oregon Department of Fish and Wildlife’s Marine Mammal Program conducted a coastwide aerial photographic survey of Steller sea lions (Eumetopias jubatus) on 3 July 2025, timed to coincide with the peak of the breeding season after most pups had been born. A total of 9,287 sea lions were counted, including 2,565 pups and 6,722 non-pups. Applying survey correction factors developed for Steller sea lions in British Columbia, Canada, the total population during the 2025 breeding season was estimated to be between 11,000 and 12,500 animals. The largest aggregation was at the Pyramid Rock rookery at Rogue Reef, accounting for just over one-quarter of all animals counted ashore. Counts of both pups and non-pups in 2025 were the highest recorded in Oregon since surveys began in the late 1970s and reflect ongoing long-term population growth in the state and across the eastern Distinct Population Segment (DPS) of Steller sea lions, which ranges from California to southeast Alaska. Future work will include periodic statewide surveys, targeted site assessments, and long-term trend analyses to inform local-, state- and DPS-level management and conservation planning.

Purpose:

Time Period of Content: July 2025

Geographic Extent: Oregon coast

Status: Final

Use Constraints:

Format: PDF

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