Environmental and fisheries managers urgently need reliable data to underpin strategies to conserve or improve the ecosystems of normally-closed estuaries in the central region of the south coast of Western Australia. These managers thus need:
1. An understanding of the current status of the fish fauna of the highly-degraded Culham Inlet, and particularly of its population of black bream, and how that status has been influenced by extreme environmental perturbations in the recent past.
2. Reliable information on the extent to which the extreme environmental conditions experienced in certain of the last ten to fifteen years influenced either the spawning success and/or survival of the 0+ age class of black bream in Culham Inlet.
3. An understanding of the current status of the fish fauna of Stokes Inlet, which is less degraded than Culham Inlet but is still the subject of concern for local residents and visitors, and of Hamersley Inlet in whose catchment the vegetation has been the subject of only a relatively low level of clearing.
4. An ability to predict, qualitatively, the extent to which continuing degradation of any normally-closed estuary in the central region of the south coast of Western Australia will affect the fish faunas of those estuaries and, in particular, their recreational and commercial fish species. This information is required by the Department of Fisheries WA for developing its overall plan for managing the recreational and commercial fisheries in these estuaries (R. Lenanton, pers. comm.) and by other governmental authorities for developing strategies for conserving or restoring the quality of the important environments afforded by these estuaries.