Classifying estuarine habitats and predicting their fish faunas – tools for managers and ecologists

This presentation will focus on a quantitative scheme for classifying nearshore habitat types and predicting their fish faunas, which has been developed for a range of estuaries in south-western Australia that differ widely in their geographical and geomorphological characteristics. This scheme provides a reliable framework for managers and ecologists to (i) investigate relationships between habitat types and faunal composition at local to regional scales and under different geographic and estuarytype scenarios, (ii) establish benchmarks against which the impact of future environmental change can be assessed and (iii) predict the habitat type and characteristic fauna of any nearshore site of interest within those systems. The habitat classification scheme has been based on the use of enduring environmental criteria that can be easily measured in GIS from mapped data sources such as satellite imagery and bathymetric charts, and has employed novel applications of relatively new multivariate routines. The results of this classification scheme, and the relationships between the derived habitat types and their fish assemblages, will be presented for five estuaries across south-western Australia, namely the permanently open Swan-Canning and Peel-Harvey estuaries, the seasonally-open Broke and Wilson inlets and the normally-closed Wellstead Estuary. Questions regarding the importance of geographical location and estuary type in structuring habitat types and their fish faunas will also be addressed.