FRDC-DCCEE: management implications of climate change effect on fisheries in Western Australia
This project addresses priority questions in the Adaptation Research Plan on commercial and recreational fishing and key components of the WA Program of the Action Plan.
Some key environmental trends affecting WA include:
· increasing frequency of ENSO events;
· strengthening of decadal variability of the Leeuwin Current superimposed on its slowly weakening trend;
· increase in water temperature and salinity;
· change in frequency of storms affecting the lower west coast; and
· change in frequency of cyclones affecting the north-west.
The WA coast includes tropical and temperate regions and under the global change induced temperature warming, there is a tendency for the southward expansion of tropical waters.
WAMSI Node 2 focused on Indian Ocean, the Leeuwin Current and their local impacts on a coastal location at Ningaloo and there is a need to examine other coastal locations as these will have an effect on most WA fisheries. Climate change affects life cycle of fish stocks by altering seasonal cycles and long term trends of the physical environment which can have a significant effect on biological parameters that are used in population dynamic models. Long-term changes in the abundance of fish stocks require an adjustment of effort or catch quota, for the stocks to be managed sustainably. Stocks are vulnerable to collapsing if there is a series of low recruitment (due to environment conditions) and heavy fishing is allowed to continue. Changes in the spatial distribution of stocks also require management consideration of any boundaries that occur in the fishery. The fisheries in this region are generally researched and managed by one jurisdiction (DoF) which must develop a policy for dealing with the possible changes. There is an important need to develop this management policy in consultation with commercial and recreational groups to deal with expected changes.