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Coupling Fisher Behavior with the System that Drives it: Using Vessel Monitoring System Data to Track Fishing Characteristics in Bering Sea Fishery for Walleye Pollock

In the last two decades, the Bering Sea Pollock fleet has seen many changes, including the creation of catch shares, spatial closures for Steller sea lion conservation and salmon bycatch protection, and the development of a hard cap and incentive measures to reduce Chinook bycatch. Meanwhile, numerous studies have either examined or predicted large-scale changes in the Alaska marine ecosystems as a result of regime shifts and longer-term changes in climate. Using observer, fish ticket, and vessel monitoring system data, we reconstructed the paths of nearly 50,000 trips made by catcher vessels that fished for Pollock in the Bering Sea from 2003 - 2013. We divided fishing trips into those targeting Pollock in the Bering Sea or those targeting other species or other regions of the North Pacific. By then characterizing trip durations and distances, we were able to quantify catch per unit effort (CPUE) for observed and unobserved fishing trips, as well as vessels’ time and distance traveled from port. This fisher-centric effort was compared with the stock-centric version of CPUE, which bases effort on haul durations instead of trip durations, to better understand how these factors are related over time. We were also able to examine the impact of warm and cold years on vessel behavior, and how targeting behaviors varied with changing economic conditions, bycatch, and total allowable catch (TAC).