Multi-variate Analysis of Biomarker Responses in Mytilus edulis and Carcinus maenas from the Tees Estuary (UK)

A suite of six biomarkers was measured in shore crabs (Carcinus maenas) and mussels (Mytilus edulis) deployed at, or native to, the Tees Estuary in north-east England, as well as at several control sites. LC-50 tests on water samples from the field sites were carried out using the marine copepod Tisbe battagliai and Microtox™ assays. Biomarker responses varied among the sites. Results were analysed using novel multivariate statistical procedures. A clearer overall picture was obtained from multi-dimensional scaling plots than by examining the data for different biomarkers individually. It was possible to distinguish among contaminated and control sites, with the contaminated sites being further differentiated to reflect a pollution gradient. It was concluded that multi-dimensional scaling procedures are a valuable additional tool for improving the analysis and interpretation of complex suites of biomarker data.