Advice on the dimensions of the escape mechanism in American lobster (Homarus americanus) commercialfishing traps in the southern Gulf of St. Lawrence

Abstract

The escape mechanism on commercial American Lobster (Homarus americanus) fishing traps is a key conservation measure as it allows under-sized Lobsters to exit the trap. This in turn reduces injury and mortality to these Lobsters, both within the traps (e.g., from other Lobsters) and at the surface (e.g., from handling and from predation upon return to the water). In addition, the escape mechanism can allow non-target species [e.g., Rock Crab (Cancer irroratus)] to exit Lobster traps. The minimum required dimensions of the escape mechanism form part of the Lobster management measures and are dependent on the Minimum Legal carapace Size (MLS) as larger Lobsters need larger openings to exit the traps. For example, the 2022 management measures for Lobster Fishing Areas (LFAs) 23, 24, 26A and 26B, provide two options for minimum escape mechanism length, 127 mm and 254 mm, and indicate the corresponding minimum escape mechanism heights required at MLSs of 73 mm to >76 mm and 73 mm to 80 mm, respectively (DFO 2022). As the MLS is now 82.5 mm in Lobster Fishing Area (LFA) 26B, and may eventually reach 80 mm or above in other LFAs, Fisheries Resource Management requested advice on the height and length of the escape mechanism at larger MLSs. This Science Response Report results from the Regional Peer Review of May 4, 2022 on Advice on the dimensions of the escape mechanism in American lobster (Homarus americanus) commercial fishing traps in the southern Gulf of St. Lawrence.