Bering Sea | Fishes and Fish Habitats DOCTORATE ORAL PRESENTATION Building a climate change and ocean acidification stress indicator for Bering Sea red king crab fisheries management Presenter: Esther Kennedy , egkennedy@ucdavis.edu, University of California Davis Jessica Cross , jessica.cross@noaa.gov, NOAA PMEL Darren Pilcher , darren.pilcher@noaa.gov, CICOES, Pacific Marine Environmental Laboratory Kiva Oken , kiva.oken@noaa.gov, NOAA Northwest Fisheries Science Center Eric Sanford , edsanford@ucdavis.edu, University of California Davis/Bodega Marine Laboratory Hongjie Wang , hwang@uri.edu, University of Rhode Island Bering Sea red king crab (RKC; Paralithodes camtschaticus ) face an array of intersecting challenges, including ocean warming and acidification. To maintain a sustainable fishery that will be resilient to future climate stress, managers need actionable information regarding the relationships between oceanographic conditions and king crab populations. Existing studies demonstrate that RKC migratory patterns and spatiotemporal distributions change in colder years relative to warmer ones. Though it has been suggested that changes in carbonate chemistry, and specifically ocean acidification, may cause similar changes in RKC populations, managers have faced two key hurdles in testing this hypothesis: 1) the scarcity of oceanographic observations, especially for ocean acidification, limits our understanding of local and regional environmental stressors; and 2) while juvenile king crab are the most vulnerable life stage to acidification, adult crab are the only age group that can be effectively surveyed. To address the scarcity of oceanographic data, here we leverage a regional ocean acidification hindcast model (Bering10K) to evaluate local oceanographic conditions in the context of regional environmental change from 1985 to the present. We then use species distribution models with spatial and spatiotemporal random effects to evaluate small differences in adult crab distributions, capitalizing on the more subtle changes in behavior and mortality that adult RKC populations display to oceanographic stress relative to juveniles. We interpret our results in the context of changing ocean conditions, predator and prey abundances, and the management areas. We find that shelf-wide temperature is more important to crab distributions than local temperature, that temperature and acidification influences can be effectively separated, and that local and shelf-wide pH are not predictive of crab distributions. In context with a growing body of complementary research, this work provides a framework to link RKC distributions to real-world stressors and identify risks and resilience in the RKC fishery. Elizabeth Siddon , elizabeth.siddon@noaa.gov, NOAA Alaska Fisheries Science Center Tessa Hill , tmhill@ucdavis.edu, University of California Davis/Bodega Marine Laboratory
Alaska Marine Science Symposium 2023 44
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