Project number: 2019-062
Project Status:
Budget expenditure: $689,479.00
Principal Investigator: Julie B. Robins
Organisation: Department of Agriculture and Fisheries EcoScience Precinct
Project start/end date: 30 Jun 2020 - 29 Jun 2024


Critical to the Harvest Strategy for the Qld Mud Crab Fishery are processes for monitoring and assessing fishery performance. Currently, the empirical and estimated indicators for this fishery are based on non-validated harvest and effort. Proposed fishery reforms (i.e., prior reporting of landings and 'market' tagging of harvested crabs) should improve harvest data reliability. Qld GMC are effectively a data-limited species because they cannot be reliably aged, associated effort data is incomplete and potting is a passive fishing technique. Commercial CPUE may not represent changes in population abundance due to variable catchability, hyper-stability and serial depletion. Additionally, there is no index of female abundance nor a male:female ratio to inform spawning-recruitment relationships. It is generally assumed that conservative management of GMC ensures their sustainability. However, evidence from the Northern Territory Western Gulf of Carpentaria suggests that GMC are vulnerable to environmental events (drought + heat = 2015 cohort failure). Gaining a rudimentary understanding of critical aspects of the GMC life cycle in Qld would be prudent (i.e., female abundance, spawning vicinities).

A Total Allowable Catch (TAC) is a key aspect of reform to Qld fisheries. The initial TACs for Qld GMC were informed by a modified catch-MSY analysis (Northrop et al., 2019). Catch-MSY is widely applied in Australian fisheries to data-limited species (FRDC 2017/102). The assessment was performed at large spatial scales (East Coast and Gulf). However, this fails to capture regional variability in spawning-recruitment processes that impact on harvestable biomass e.g., larval dispersal due to oceanic circulation patterns and survival of juvenile crabs due to regional rainfall, flow, temperature, and sea level variations. The proposed research is needed (in the short-term) to gather appropriate quantitative biological information and to develop (for the long-term) a means to cost-effectively monitor Qld GMC populations to support a data-moderate stock assessment approach. The research also aims to address some of the critical knowledge gaps in GMC life history that have been unresolved for over 40 yrs.


1. Assess the utility of next generation genetic analysis to inform spatial stock structure of the Giant Mud Crab (Scylla serrata), using South East Queensland and northern New South Wales as a case study.
2. Develop and assess the feasibility of ‘survey’ pots suitable for long-term implementation as a means of monitoring Giant Mud Crabs.
3. Gather key quantitative biological information on Giant Mud Crabs relevant to assessment and management, including the use of tagging studies and a pilot evaluation of means to understand the spawning migration of female Giant Mud Crabs.

Fact sheet

Author: DAF
Fact Sheet • 2020-12-01 • 350.98 KB
FRDC-DAF Mud crab factsheet.pdf


Researchers from the Department of Agriculture and Fisheries (DAF) Queensland, CQUniversity (CQU) and the Department of Primary Industries (DPI) NSW Fisheries are collaborating on a Fisheries Research and Development (FRDC) co-funded research project on mud crab populations in Queensland. The project aims to provide a better information base to assess and sustainably manage Queensland mud crab fisheries.

Project products

Flyer • 2020-12-01 • 279.98 KB
FRDC-DAF Mud crab flyer.pdf


Researchers are asking recreational and commercial fishers in Queensland and New South Wales to report sightings of egg-bearing female mud crabs. 

Related research


Developing a Kimberley Aboriginal Mud Crab Fishery

1. Determine the biology and distribution of mud crab species (Scylla serrata and S. olivacea) in King Sound and Cambridge Gulf areas of the Kimberley region of Western Australia.
Department of Primary Industries and Regional Development (DPIRD) WA

Assessment of the interactive effects of climate change, floods and discard stress on the commercially important Mud Crab (Scylla serrata) and Blue Swimmer Crab (Portunus armatus) - postgraduate

1. Provide the opportunity for a post-graduate research student to work with industry and managers, gain exposure to stakeholder’s perspectives on the issue and undertake high-quality research that results in the production of scientific outputs.
Southern Cross University (SCU) National Marine Science Centre