Catch and release mortality estimates play an important role in management models and also provide anglers with information on their impacts to local stocks. Over the recent past, the PIER team has performed catch and release survivorship studies on several pelagic species. Most of the survivorship studies have been through collaborative projects with the National Marine Fisheries Service Bycatch Reduction and Engineering Program (NMFS/NOAA).
Documenting gear impacts and the disposition of released catch continues to be an important topic for resource managers on the West Coast. Over the recent past PIER has performed post release survival studies on several pelagic species including thresher sharks, Pacific Bluefin tuna, and roosterfish.
See Past Publications for more information
Survivorship in Commercial Fisheries
Survivorship studies are an important component in commercial gear development as it gives researchers, fishers, and managers insight into potential mitigation strategies to reduce bycatch mortality and, in cases such as deep set gear where survivorship is high, allows fishers to demand a price premium for their low-impact harvest techniques.
The Pacific Bluefin Tuna (PBT), Thunnus orientalis is a wide-ranging pelagic species that spawns in the western Pacific. Despite recent periods of localized juvenile bluefin abundance off southern California, updated population assessments have shown a steep decline in the number of spawning adults. Suppressed abundance of mature PBT within distinct spawning grounds around the Philippines and Sea of Japan has prompted increased fishery restrictions across the Pacific, including California recreational bag limit reductions.
Off California, the PBT fishery is focused primarily on juveniles ranging in size from just a few pounds to over 300. It has been proposed that all PBT are spawned in the Western Pacific and a portion of the stock migrates across the Pacific at an early age to the rich foraging grounds off the U.S. West Coast and Mexico. Juvenile PBT may remain off Baja California and the U.S. west coast for several years before returning to the western Pacific upon reaching sexual maturity. Throughout their extensive migration, PBT are targeted by a variety of fisheries, including directed effort by California recreational anglers. Considering recent California recreational fishery bag limit reduction from 10 fish/day to 2 fish/day, recent tagging work by PIER researchers has focused on assessing post-release survivorship and documenting best practices for anglers that release their catch.
