South African estuaries and their importance to fishes

In this article environmental conditions typical of South African estuaries are contrasted with those of marine inshore waters in order to emphasize that estuarine fishes comprise a specialised component of the marine fauna. The life cycle of estuarine fishes is described and related to important physical and biological characteristics of estuaries. The fish fauna is divided into six categories according to the extent of their dependence on estuaries. This is followed by discussion of the effects of estuarine degradation on these groups. It is concluded that continuing degradation will result in a decline in South Africa's estuarine fish fauna.