Short‐term fishery gains mask long‐term resource pains: Spatial fisheries management changes promote hyperstable CPUE in Labrador snow crab Chionoecetes opilio during a period of heavy exploitation

Abstract

ObjectiveThe snow crab Chionoecetes opilio resource in Assessment Division 2HJ has experienced prolonged high exploitation rates and reduced exploitable biomass over the past two decades. We aimed to explore whether this poor state of the resource is associated with spatial management changes made in 2003 and 2013.MethodsWe tested for differences in fishery performance trends before and after the implementation of spatial management which include standardized CPUE, spatial extent of fishing effort, and size at maturity of male snow crabs.ResultThe results show that spatial regulatory changes were successful in increasing fishery catch rates in the short term but that chronic high exploitation eventually overrode these gains, with contracted fishing patterns leading to increased localized depletion rates on dominant stock components. This ultimately culminated in a downward shift in size at maturity and other concerning biological outcomes.ConclusionThe analysis demonstrates spatial management measures contributed to the present poor state of Assessment Division 2HJ snow crab and that such measures should serve as complements to—not replacements for—stringent quota control.