Use of escape gaps in Barents Sea snow crab (Chionoecetes opilio) fishery: Can it reduce bycatch of undersized crabs?

Snow crab (Chionoecetes opilio), like several other crustacean species, are commonly captured using trap gear, which is designed as conical pots. Many such pot fisheries employ some selectivity mechanisms that allow release of captured small or undersized individuals on the seabed, thus improving survival of escapees and reducing workload for the fishers. In snow crab pot fisheries, the selectivity mechanism is based mainly on crab escape through netting meshes (diamond-shaped mesh with sizes ranging from 120 – 140 mm). However, several observations have shown that in commercial snow crab pot fisheries, catches contain undersized snow crabs. Therefore, this study aimed to test the use of escape gaps in the Barents Sea snow crab fishery to evaluate whether it can reduce the bycatch of undersized crabs and sharpen size selectivity. The results showed that both standard pots using mesh selection and test pots with escape gaps reduced catches of undersized snow crabs. However, pots with escape gaps significantly reduced the capture of undersized crabs compared to pots that used only netting mesh selection. This result can be important for the commercial fishery, especially considering areas with larger abundances of small snow crabs, where improved size selection could result in reduced workload for catch sorting and potential crab mortality due to the associated handling.