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Tangle Nets and Gill Nets as a Live Capture Selective Method to Collect Fall Chinook Salmon Broodstock in the Okanogan River: 2004

Category: Fishing / Shellfishing - Selective Fishing

Date Published: May 2005

Number of Pages: 20

Author(s): C. E. Ashbrook, K. W. Yi, J. Arterburn

Selective fishing methods often rely on modified fishing gears and methods to capture and release non-target species or stocks in a manner that minimizes mortality. Consequently, these methods are expected to also provide a way to capture live salmon as broodstock for hatchery programs. Tangle nets have been shown to improve the long-term survival of released salmon when compared to the conventional gill nets during commercial fisheries. To evaluate the feasibility of using commercial selective fishing methods for broodstock collection and harvest opportunities, a pilot study was conducted in the Okanogan River in an area where tribal gill net fishing typically occurs. The goal of the study was to compare tangle nets to gill nets for collecting fall chinook salmon (Oncorhynchus tshawytscha) and to evaluate their impacts on non-target species. Researchers fished 4.5" tangle and 6" gill nets for eight nights and collected data on the species captured and all salmonids’ condition at capture and release. Salmonids also were tagged at release for recovery information from sport fisheries, tribal fisheries, and during spawning ground surveys. In addition to chinook, steelhead salmon (Oncorhynchus mykiss), and sockeye salmon (Oncorhynchus nerka) were captured. Regardless of net type or species, salmonids were typically captured in lethargic condition and released in lively condition. The tangle net captured much more bycatch than the gill net and pulling the tangle net in required significantly more time because of bycatch and river debris. The expected late portion of the fall chinook run did not occur, and only two target fish were captured, one per net type. Recommendations are provided to conduct further evaluation.