EVALUATION OF POUND NETS AS STOCK SELECTIVE FISHING TOOLS IN THE LOWER COLUMBIA SUB-BASIN AWARD # NA17NMF4720255 BREP PERFORMANCE PROGRESS REPORT Award Period – July 1st, 2017 - June 30th, 2018 Reporting Period – January 1st, 2018 – June 30th, 2018 Submitted To: Erin Wilkinson NOAA Fisheries 1315 East-West Highway Silver Spring, MD 20910 Submitted By: Nick Gayeski, Ph.D. Adrian Tuohy, M.S. Wild Fish Conservancy P.O Box 402 Duvall, WA 98019 July 2018 GAYESKI AND TUOHY – BREP PERFORMANCE PROGRESS REPORT – JULY 2018 ACKNOWLEDGMENTS This project would not have been possible without funding received under award NA17NMF4720255 from the National Oceanic and Atmospheric Administration (NOAA) Fisheries Service, in cooperation with the Bycatch Reduction Engineering Program (BREP). We are grateful for additional support and funding provided by the Washington Coastal Restoration Initiative, the Washington Department of Fish and Wildlife (WDFW), and the Patagonia World Trout Grant Initiative. We would like to thank the many people that collaborated and contributed to this study to make it a success: Blair Peterson for his knowledge of traps and skill as a commercial fisherman; Dr. John Skalski and Dr. Thomas Quinn of the University of Washington for technical guidance, support, and review; Ron Warren and Bill Tweit of WDFW for administrative support; the community of Cathlamet, WA for its generous hospitality; and volunteers Blake Joplin and Mary Valentine for their remarkable endurance and commitment to quality. The statements, findings, conclusions, and recommendations from this performance progress report are those of Wild Fish Conservancy and do not necessarily reflect the views of NOAA Fisheries. 2 GAYESKI AND TUOHY – BREP PERFORMANCE PROGRESS REPORT – JULY 2018 TABLE OF CONTENTS ACKNOWLEDGMENTS .............................................................................................................2 II. ABSTRACT ...............................................................................................................................4 III. EXECUTIVE SUMMARY .....................................................................................................5 IV. PURPOSE ................................................................................................................................7 A. Description of the Problem...........................................................................................7 B. Objectives of the Project .............................................................................................12 V. APPROACH ............................................................................................................................13 A. Description of the Work Performed ..........................................................................13 B. Project Management ...................................................................................................25 VI. FINDINGS..............................................................................................................................27 A. Actual Accomplishments and Findings .....................................................................27 B. Significant Problems ...................................................................................................41 C. Need for Additional Work ..........................................................................................41 VII. EVALUATION ....................................................................................................................42 A. Attainment of Project Goals and Objectives ............................................................42 B. Dissemination of Project Results ...............................................................................50 C. Applications, Benefits, and Conclusions ...................................................................52 REFERENCES .............................................................................................................................54 APPENDICES ..............................................................................................................................65 A. Bayesian Survival Analysis ........................................................................................65 B. Project Photographs ....................................................................................................72 C. Catch Totals .................................................................................................................84 3 GAYESKI AND TUOHY – BREP PERFORMANCE PROGRESS REPORT – JULY 2018 II. ABSTRACT Gillnets and other conventional harvest techniques utilized in mixed-stock commercial salmon fisheries frequently result in bycatch mortality. In many parts of the U.S Pacific Northwest, bycatch and hatchery impacts impede the recovery of Endangered Species Act (ESA)-listed salmonids and constrain commercial fishing opportunities. For the benefit of wild salmon, threatened ecosystems, and coastal fishing communities, a post-release survival study was conducted on the lower Columbia River to evaluate the potential of an alternative commercial gear—an experimental pound net trap—as a live-capture, stock-selective harvest technique. Expanding upon a 2016 pilot study, a modified trap was constructed and operated under a variety of tidal stages, light levels, and weather conditions between August 26 and September 27, 2017. Utilizing a paired mark-release-recapture procedure with Passive Integrated Transponder (PIT) tags, post-release survival from the trap was estimated through the Cormack- Jolly-Seber method; catch-per-unit-effort (CPUE) and covariates of CPUE were analyzed through Generalized Linear Models (GLM). Results demonstrated that pound net traps can effectively target commercially viable quantities of hatchery reared fall Chinook (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) while reducing cumulative bycatch mortality of ESA- listed species relative to conventional and alternative commercial gears. During the study period, 7,129 salmonids were captured and released. The ratio of wild to hatchery-origin salmonids captured was approximately 1:3. Cumulative survival to McNary Dam ranged from 94.4% for steelhead trout (O. mykiss) to 99.5% for Chinook salmon, warranting application of the gear as a stock-selective harvest tool in commercial salmon fisheries. 4 GAYESKI AND TUOHY – BREP PERFORMANCE PROGRESS REPORT – JULY 2018 III. EXECUTIVE SUMMARY With continuation of salmonid hatchery programs in the Columbia River Basin and elsewhere in the U.S Pacific Northwest, development and implementation of stock-selective commercial harvest tools for improved targeting of hatchery-origin fishes and reduction of bycatch impacts has been recognized as a necessary means to enable and expand commercial fishing opportunities while minimizing take of threatened and endangered salmonids under the Endangered Species Act (ESA). To benefit wild salmonid recovery and fisheries of the lower Columbia River, Wild Fish Conservancy (WFC) received funding from NOAA Fisheries Service BREP to expand upon a 2016 pilot study evaluating the potential of an alternative commercial gear—an experimental pound net trap—as a stock-selective, sustainable harvest technique. The project had three major goals: 1) test and refine deployment and operation of a modified pound net trap in the lower Columbia River; 2) determine the effectiveness of the harvest method in capturing salmon relative to previously tested alternative gears in the region; and 3) evaluate the ability of the gear to protect non-target species through identification of capture and release conditions, immediate survival, and post-release survival of fall Chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (O. mykiss). The experimental pound net trap was successfully constructed by WFC and a local commercial fisherman in August 2017. Modifications were made based upon previous experiences in the 2016 pilot season and the designs of other alternative fishing gears tested throughout the Pacific Northwest. Test fishing and research activities proceeded from August 26 through September 27, 2017. Mirroring prior alternative gear evaluations in the lower Columbia River, WFC utilized a paired mark-release-recapture methodology with Passive Integrated Transponder (PIT) tags to estimate post-release survival from the experimental trap. Upstream detections of tagged and released fall Chinook salmon and steelhead trout were compared to that of a control source of fish through the Cormack-Jolly-Seber method; total catch, CPUE, capture/release conditions, immediate survival, and CPUE covariates were measured and analyzed. By September 27, 2017, a total of 2,851 treatment and control Chinook salmon and steelhead trout were PIT tagged and released at the experimental trap site. All tagged fish were queried for detections at PIT tag arrays at various dams and hatcheries located upstream. Unique tag detection histories were recovered through the PIT Tag Recovery Information System (PTAGIS). Results demonstrated that pound net traps can effectively target commercially viable quantities of hatchery reared fall Chinook and coho salmon (O. kisutch) while reducing cumulative bycatch mortality of ESA-listed species relative to conventional and alternative commercial gears. During the study period, 7,129 salmonids were captured and released. The ratio of wild to hatchery-origin salmonids captured was approximately