The giant mud crab is an iconic species targeted by commercial, recreational and Indigenous fisheries in northern Australia. Despite their high value, the total harvest of Queensland mud crabs across all fishery sectors is not well understood. In 2021, a Harvest Strategy including a Total Allowable Catch (TAC) and Individual Transferable Quotas was introduced to the Queensland fishery. The TAC was set at a precautionary level below previous commercial harvest rates.
Monitoring and assessment of fishery performance is a key information need in the context of a changing climate. In this presentation, we provide the results of various field monitoring trials conducted from 2021-2024 to gather data on pre-recruits, length-frequency, and mortality. We trialled fishery independent surveys using different gears, fishery dependent surveys with scientists working on commercial vessels, and utilising commercial fishing data as an information source. We also investigated tag-recapture methods, and the feasibility of survey pots deployed by commercial fishers. We discuss benefits, known or potential biases in each data set, and the challenges with monitoring mud crabs, including environmental responses. The project aimed to use multiple lines of evidence to shift the species from data-limited, towards a better understanding of the drivers of harvest and abundance.