Improving bycatch reduction strategies and escape vents in Queensland crab fisheries

The Queensland Crab Fishery is an iconic fishery, which encompasses the harvest of mud crabs (Scylla serrata, the Giant Mud Crab, and Scylla olivacea, the Orange Mud Crab) and Blue Swimmer Crabs (Portunus armatus and Portunus pelagicus), predominately using baited crab pots of various designs. The Fishery has a limited entry commercial sector that requires a C1 symbol to catch these species of crabs, plus possession of appropriate quota to catch mud crabs on the Queensland East Coast (EC1), Queensland Gulf of Carpentaria (GC1) or Blue Swimmer Crabs anywhere in Queensland (BC1). The Fishery also has a significant recreational sector, that uses similar apparatus and does not require a licence, but does have in possession limits. The current research investigated the performance of escape vents in crab pots targeting Giant Mud Crabs to determine if current Queensland fisheries regulations should be revised to provide better commercial outcomes (i.e., retention of legal mud crabs – male and 150 mm carapace width or greater), whilst minimising the bycatch of non-legal crabs, finfish and other bycatch species, such as water rats. The research focussed on the Giant Mud Crab as it comprises greater than 99% of the commercial harvest of mud crabs in Queensland. The ongoing issue of marine turtle interactions with crabbing apparatus, including a recent increase of stranding reports, led to the research also collating available information about these interactions to support a risk mitigation strategy for the fishery’s interaction with protected marine turtle species. Results are to be considered by management, Fisheries Queensland and the Crab Working Group as part of the Harvest Strategy arrangements for the Queensland Crab Fishery.