Escape mechanisms in crab and lobster pots: implications for snow crab (chionoecetes opilio) stock conservation and policy review

Since the collapse of groundfish stocks in the early 1990s, market demand and industry diversification has placed considerable pressure upon crab stocks in Newfoundland and Labrador, specifically snow crab (Chionoecetes opilio). The total allowable catch (TAC) for snow crab in the Newfoundland region peaked in 1999 at 69,000 tonnes. Fisheries and Oceans Canada has been reactive in its approach to management and has implemented various measures in line with the precautionary approach. -- Work conducted on modifications to crab pots, specifically the development of escape mechanisms for undersized crab, has generated attention as a means to improve sustainability of the resource. commentary from local crab harvesters using experimental escape devices in their pots has been positive in that they are seeing less undersized crab in their catch. This translates to reduced sorting time for the harvester, less mortality, and fewer non-commercial crab exposed to air and drop factors. This further increases the chance that these undersized individuals will be available for harvest in subsequent years. -- The use of escape mechanisms in shellfish fisheries is not a new concept. Reducing ghost fishing of lost and derelict gear has prompted research that has translated into new management measures in many jurisdictions. Reducing the incidental capture of undersized crab and lobster has been an additional outcome of escape device utilization is most crab and lobster fisheries around the world. -- Experiments were conducted in Newfoundland as early as the 1890s with escape devices in lobster gear. While lath spacing in lobster pots has been enforced since 1937 it is interesting that the use of rigid escape mechanisms in snow crab pots has not yet been adopted as a mandatory management measure although efforts to recommend policy changes have been underway since 2004 in the region. -- The following document reviews the use of escape mechanisms in different decapods fisheries around the world, benefits of their use in Newfoundland and Labrador, and the implications for snow crab stock conservation and policy review