Dr. Melissa Haltuch1, Z. Teresa A’mar2, Nicholas A. Bond3, and Juan L. Valero4
1Northwest Fisheries Science Center, 2Alaska Fisheries Science Center, 3University of Washington, and 4Center for the Advancement of Population Assessment Methodology
March 10, 2015 9:00 (PST): FSH 213
Assessing the effects of climate change on U.S. west coast sablefish productivity and on the performance of alternative management strategies.
The U.S. west coast sablefish fishery is a valuable commercially targeted species, making assessing and understanding the interaction between climate change and fishing a priority for (1) forecasting future stock productivity and (2) for testing the robustness management strategies to climate variability and change. The horizontal-advection bottom-up forcing paradigm describes large-scale climate forcing that drives regional changes in alongshore and cross-shelf ocean transport, directly impacting the transport of nutrients, mass, and organisms. This concept provides a mechanistic framework through which climate variability and change alter sea surface height (SSH), zooplankton community structure, and sablefish recruitment, all of which are regionally correlated. This study assesses future trends in sablefish productivity as well as the robustness of harvest control rules to climate driven changes in recruitment by conducting a management strategy evaluation of the currently implemented harvest control rule as well as an alternative. We use 50 year ensemble forecasts of sablefish productivity under a suite of future climate variability and change scenarios. Future recruitments are generated under two scenarios (1) the fit of a Beverton-Holt stock-recruitment curve based on historical data and (2) recruitments driven by a SSH-recruitment relationship that is treated as an age-0 survey of abundance with associated uncertainty. Multi-decadal forecasts of sablefish productivity could provide long term strategic advice to allow fishers and managers to plan for and respond to shifts in productivity.