Budget expenditure: $700,000.00
Project Status:
Current
Principal Investigator: Matt D. Taylor
Organisation: NSW Department Of Primary Industries
Project start/end date: 16 May 2018 - 15 Jun 2022
Contact:
FRDC
TAGS
Reproduction
Recreational Fishing
Modelling
Migration
Habitat
SPECIES
Blue Swimmer Crab
Mud Crabs

Need

The spawning dynamics and early life history are largely unknown for BSC and GMC in NSW, as are spawning areas, sources and sinks, important juvenile nurseries, and the effect of environmental variability on both spawning and recruitment. While this has led to some limitations to management and uncertainty in the past, NSW have recently launched two major management initiatives for the species for which this information is essential: 1) management of commercial BSC and GMC harvest through share-linked catch quota; and 2) fisheries enhancement for BSC and GMC.

In 2017, the Commercial Fisheries Adjustment Program has seen the NSW Government subsidise the investments of many fishing businesses to access catch quota for BSC and GMC. Quota allocation depends on scientifically-based assessment of Total Allowable Catch (TAC). At present the only source of information on which to base TAC is historic catch and effort, but these are highly variable and the mechanistic factors underlying this variation are unclear. The recent NSW Marine Stocking Fishery Management Strategy outlines the development of release programs for both BSC and GMC. Effective implementation of this strategy relies on a thorough knowledge of the requirements of young crabs and the factors affecting their recruitment such that recruitment limitation can be identified and releases targeted to address it (see Taylor, 2017). Through a review of existing work on these species in other states, and consultation with managers and industry, we have identified targeted research questions that will directly enhance the capacity of NSW DPI-Fisheries to design and implement effective harvest management, fishery enhancement and restoration programs for BSC and GMC. The need for this information is especially evident in the attached letters of support from commercial and recreational stakeholders, and the contribution of $250K cash from the NSW Recreational Fishing Saltwater Trust.

Objectives

1. Describe temporal and spatial patterns in settlement and juvenile habitat use, to determine if spawning, nursery habitat availability, or connectivity creates localised recruitment bottlenecks in NSW estuaries
2. Define and model links between environmental (physicochemical and oceanographic) variables and these patterns, and potential effects on catch rates
3. Use this information to develop an independent measure of recruitment, which links the effects of environmental variability on recruitment to future catch quotas
4. Interpret patterns in recruitment limitation to target a large-scale release of BSC, and analyse post-release abundance patterns to better understand recruitment bottlenecks and improve modelled relationships

Related research

Environment
Environment
Industry
PROJECT NUMBER • 2018-024
PROJECT STATUS:
CURRENT

Investigation and Improvement of Live Blue Swimmer Crab Handling in NSW

1. To produce handling guidelines and conduct a series of industry training workshops to reduce the mortality rate of blue swimmer crabs and thereby increase the volume of live product to market
ORGANISATION:
Department of Agriculture and Fisheries EcoScience Precinct