There is a critical need for a reliable stock monitoring system for future management of the important multispecies commercial and recreational finfish fishery in the south west of Western Australia. Specifically a robust annual recruitment index for monitoring long term trends in abundance for the key finfish species is needed. The proposed recruitment index survey system is also required to complement and improve the usefulness of existing long-run commercial catch and effort records.

In order to develop a cost effective index system, there is a need to collect sufficient data on the spatial and temporal abundance of each species, within a rigorously planned experimental framework, to allow maximum use of current statistical techniques.

The comprehensive statistical approach to the survey design proposed for this project, although not previously applied to the development of finfish recruitment indices, will enable the dimensions, and hence cost, of the long term field sampling to be minimised.