Multivariate Approaches for Bioassessment of Water Quality

Multivariate methods for bioassessment of water quality aim to be more ‘objective’ than biotic indices (BI) and indices of biotic integrity (IBI) described in the preceding chapters. In the multivariate approaches, statistical tools are used to develop relationships between fauna and water quality for an ‘ideal’ or high-quality reference site. The relationships are used to predict the fauna at any test site in the absence of pollution (or other type of stress). The observed fauna at the test site is then compared with the fauna expected at that site to make assessments of water quality at the test site.