Modelling fishing effort displacement in the Southern Gulf of St Lawrence snow crab (Chionoecetes opilio) fishery: quantifying management measures for North Atlantic Right Whale (Eubalaena glacialis) entanglement prevention

• Main Author: Cole, Alexandra
• Format: Report
• Language: unknown
• Published: 2019
• Subjects: Chionoecetes opilio; Eubalaena glacialis; North Atlantic; North Atlantic right whale; Snow crab
• Online Access: http://hdl.handle.net/10222/75138

Anthropogenic mortality is the leading factor inhibiting the recovery of the endangered North Atlantic right whale (NARW), in which 85% of human-induced deaths are caused by entanglement in commercial fishing gear. In 2017, a large number of NARW entanglements and deaths occurred in the Gulf of St Lawrence, many of which were attributed to the snow crab fishery. This led to the establishment of new management measures, including spatio-temporal fishery closures in the form of static and dynamic exclusion zones that encompassed 90% of the 2017 NARW sightings. These measures raised concerns related to the costs to the fishery and effectiveness of entanglement prevention. Using fishing data from 2005 through 2012, a model was built that predicted weekly fishing effort displacement caused by these closures, the approximated socio-economic costs of movement, and relative change in co-occurrence, or risk, of a NARW coming into contact with fishing gear. The model examined four alternative closure arrangements to evaluate NARW protection efficacy versus costs to the fishery of different management strategies. Results show that lost fishing opportunity was minimal, and estimated costs were highest and most variable in the current strategy, and lowest and most consistent in a strictly dynamic management regime. While displaced effort resulted in a fishing-the-line scenario, all strategies were successful at reducing the threat of entanglement. Subsequently, this study quantifies and examines the trade-offs of spatio-temporal fishery closures for species-at-risk protection, while providing managers with an adaptive management tool in the form of the displacement model. Keywords: spatial closures, fisheries impacts, entanglement, North Atlantic right whale, fishing effort displacement; conservation