Simon Linke, Gail Ransom, Peter Liston and Richard Norris
Co-operative Research Centre for Freshwater Ecology, University of Canberra
Department of the Environment and Heritage, 2003
ISBN 0 642 55050 6
- Australian River Assessment System: Improving AusRivAS Analytical Methods - ANNA Phase II (PDF - 856 KB)
About the report
An Australia-wide assessment of river health has been completed under the National River Health program. This assessment uses a rapid, standardised and integrated method for assessing riverine ecological health, referred to as AusRivAS (the Australian River Assessment System).
The bioassessment component of AusRivAS uses a series of models, which predict the composition of the macroinvertebrate community at a river site in the absence of any impacts (Expected taxa (E)) which is compared with the macroinvertebrate community actually found at a site (Observed taxa (O)). These models are based on data derived from the 1,500 reference sites across Australia previously collected and analysed under the National River Health Program. AusRivAS assessments are reported as the ratio of observed to expected (O/E) taxa for the site. The O/E ratio is then assigned to a band indicating a level of impact.
The statistical methods for assessing the health of Australian rivers are derivations of approaches being used in Britain involving a semi-subjective classification approach to establish groups of reference sites from which to develop predictive models. This project aims to further develop and implement an analytical approach which uses the multivariate characteristics of the whole reference data set to compare a test site against based on methods (e-ball) conceived and refined in previous research projects recently completed under the National River Health Program.