To improve the management of the Shark Bay prawn fishery there is a specific need for refined identification of areas and times of higher tiger prawn numbers relative to king prawns so that closure areas/times can be specifically targeted to protect the more vulnerable tiger prawns from over-fishing. In addition, scallop fishers have expressed concern that prawn fishing in areas of overlap with good scallop abundance is affecting the abundance of scallops. In both cases, answers would be provided by the development of a detailed space-time model for both prawn and scallop catch to identify abundance and fishing patterns and to document when and where prawn and scallop trawlers target higher abundance areas. There are now six years of precise spatial recording of prawn and scallop catch for each trawl shot and this information can be used to model the migrating king and tiger prawn stocks and to fine-tune the area-time closures that are currently in place to protect the tiger prawn breeding stock while allowing fishing on the more robust king prawn stocks.
For the scallop fishery in Shark Bay, currently, an annual pre-season scallop survey is undertaken. A spatial analysis of the relationship between the spatial distribution of the subsequent scallop catch and that of the pre-season survey will enable an assessment of the effect that prawn trawling prior to scallop fishing may have on the scallop catch. These analyses will improve the management of these fisheries ensuring optimum sustainable exploitation of valuable fish stocks.
There is a need in Australia in general, and Western Australia in particular, for more trained personnel in the area of application of geostatistics to renewable resources modelling. The involvement of an ECU research student in this project, and the recruitment of a Graduate Research Assistant, will increase the numerical fisheries modelling capacity in WA.