Poleward shifts in commercial fishing vessel distribution over the Bering Sea shelf, 2013–2022

Abstract

Recent studies have documented poleward shifts in heavily targeted fish stocks on the Bering Sea Shelf. This study investigated whether commercial fishing vessels in the region have also shifted their distribution poleward in recent years. We used Vessel Management System data generated between January 1, 2013, and December 31, 2022, to identify regions over the shelf where vessel activity increased (emerging hot spots) and where it decreased (emerging cold spots) during this time period. We hypothesized that emerging hot spots would occur at the northern edge of the vessel operating range, while emerging cold spots would occur at the southern edge. Overall, northward shifts in vessel distribution were most evident during October–February and July–August, when the range of emerging hots spots was centered 204–515 km to the N, NE, or NW of the center of the range of emerging cold spots. The trend was strongest in August, when emerging hot spots were widespread in the Northern Bering Sea. We did not attempt to identify factors driving these distributional shifts, but the timing of shifts did coincide with the busiest fishing seasons over the Bering Sea Shelf and, in part, the open seasons for walleye pollock (Gadus chalcogrammus). If groundfish populations continue to move poleward with climate change, this study may serve as a window into the early stages of a long-term redistribution of commercial fishing effort in the Bering Sea, a region supporting one of the largest fishing industries in the world.