Spatiotemporal variation of benthic communities on weathervane scallop (Patinopecten caurinus) beds with socioeconomic considerations of the commercial fishery off the coast of Alaska

Abstract

Weathervane scallops (Patinopecten caurinus [Gould, 1850]) off Alaska are commercially harvested in areas that contain commercially important groundfish and crabs. Using observer bycatch data collected during 1996-2012, we analyzed spatial and temporal patterns in community composition on weathervane scallop beds and explored whether observed patterns related to environmental variables (sediment, depth, bottom water temperature, and freshwater discharge) and anthropogenic variables (trawling and dredging effort). Significant (P<0.05) differences in community structure were observed at the scale of state fishery registration districts, as well as among individual scallop beds. Spatial differences were most strongly correlated with sediment, depth, and dredging effort. Sequential changes over time were also detected, as was a split between 1996-1999 and 2000-2012. Temporal changes were weakly yet significantly correlated with freshwater discharge and dredging effort. We also conducted a socioeconomic assessment of the commercial weathervane scallop fishery, structured within the framework of a SWOT (strengths, weaknesses, opportunities, threats) analysis. Specifically, we focused on five categories: social, technological, economic, environmental, and regulatory. Whereas the data-poor status of the stock appears to be the fishery's biggest weakness, the largest strengths are conservative management, industry self-regulation, and the fishery's small footprint. Impending threats include stock declines, effects of dredging, and changes in the structure of the fishery. These analyses provide a baseline of benthic community composition on weathervane scallop beds, as well as socioeconomic information to contribute to the environmental, economic, and social sustainability of the Alaska scallop fishery.