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Sea Lion Monitoring and Non-lethal Hazing

Dec 15, 2011


This project is collaborative with the States of Oregon and Washington, the Army Corps of Engineers (ACOE), and the U.S. Department of Agriculture (USDA). The scope of the project includes a 3 person, boat-based, sea lion hazing crew operating weekly for approximately 3 months near Bonneville Dam. This crew conducts non-lethal sea lion hazing, assists with trapping (not actual trapping) for attaching acoustic and GPS tags, and other field duties. A second objective is implementing a study to estimate sea lion predation outside of the ACOE observation area. The ACOE observation project is limited to the Bonneville Dam tailrace area that is viewable from the deck of the Dam. We are working to develop a video-based system to enumerate sea lions and predation on salmonids. A video system is deployed to observe river surface activities in quantified areas of the river. Technicians then review these time periods and note sea lion presence and predation activities. The video system was deployed within the Corps observation area below Bonneville Dam where visual observations are being made by the Corps and ground-truthing is possible. Acoustic telemetry data was collected to evaluate movements of California sea lions. Observations regarding affinity to particular feeding stations, fine scale movement of animals in the area near Bonneville Dam, and coarse scale movement of animals downstream in the lower Columbia River were made. Each of these objectives is required under the Hydro system Biological Opinion Reasonable and Prudent Actions (RPA) 49 and 69.



Hatch, D. and  J. Whiteaker. 2011. Sea lion monitoring and non-lethal hazing. Annual Report for U.S. Dept. of Energy Bonneville Power Administration, Project # 2008-004-00. Columbia River Inter-Tribal Fish Commission Technical Report 11-7. Portland, OR. 30p.



Report No.


Media Type

CRITFC Technical Report