Both the King George whiting and the Black bream are important commercial and recreational finfish species in south-western Australia. The fisheries for Black bream are restricted to estuaries, whereas the King George whiting recreational fisheries is based in both estuaries and protected marine waters. Due to the increase in catches of King George whiting and Black bream, the Western Australian Fisheries Department required research to develop management policies that will benefit both the commercial and recreational fishers who target these two species. The main biological information needed was the growth rate, maximum age, age and length at sexual maturity, spawning period and location, habitat requirements and the selectivity of gill net meshes for these species in south-western Australia.