Evaluating the environmental drivers of mud crab (Scylla serrata) catches in Australia
Mud crabs (Scylla serrata) are a fast growing, short-lived species whose abundance appears to be linked to the prevailing environmental conditions during their life history. Mud crab fisheries are typically subject to high fishing mortality rates, with little carryover of stock from one year's cohort to the next. This combination of factors means that there is often extreme inter-annual variation in mud crab catches. Such variability may be observed across several jurisdictions, can produce uncertainty for both users and resource managers alike and hinders further investment in the mud crab fishing industry.
A greater understanding of the environmental processes that drive mud crab catches will enable the development of models which will remove some of this uncertainty. Crab fishers need some forecasting ability not only to predict catch, but also to assist in their business planning. For example, crabbers entering expensive 2 or 3 year lease agreements when mud crabs are abundant may experience financial difficulties if crabs (through natural circumstances or otherwise) suddenly become scarce.
Such a model would also assist in the proactive management of the mud crab fishery, whereby catch or effort limitations could be imposed when catches are predicted to be low. However, the model would need to be tested for several years before being used as a decision making tool for management.
This study will examine cause and effect relationships at the regional, jurisdictional and national levels and take into account the various environmental/meteorological conditions operating at these different scales.
