Past and future shifts in the distribution of fisheries for juvenile albacore in the eastern North Pacific Ocean

Barbara Muhling, NOAA Southwest Fisheries Science Center, La Jolla, CA, United States; University of California - Santa Cruz, NOAA Southwest Fisheries Science Center, San Diego, CA, United States and Desiree Tommasi, University of California Santa Cruz and NOAA SWFSC, La Jolla, CA, United States
Environmentally-driven shifts in the distributions of managed species can cause problems if stock assessment and management frameworks are not robust to changes in availability among different fleets. Here, we describe how distribution and migration paths of juvenile albacore (Thunnus alalunga) respond to decadal-scale oceanographic variability in the eastern North Pacific, and how these may continue to change into the future. Latitudinal shifts in favorable fishing areas for the U.S. and Canadian surface fleets in the California Current System have implications for transboundary management, and exploitation of a shared resource. In contrast, apparent longitudinal shifts in east-west migration patterns can cause large fluctuations in fishing costs for both fleets. This can limit the utility of albacore as an open access “insurance” fleet, which west coast fishers rely on when other species are depleted or subject to closures. Our results have relevance for the prediction of future albacore movements across international boundaries, and for their effective management as climate change continues to result in novel environmental conditions in the North Pacific.