River evaluation using ecotoxicological and microbiological procedures.

One of the many problems researchers and managers face is to try and interpret data collected from various river studies. There is an underlying awareness of the incompleteness of most data bases due to a variety of problems outside of those concerning sample processing.In this study we have attempted, by using the battery of tests approach (12 tests) and the examination of different types of samples such as water, Milli-Q water extracted sediments, and organic solvent extracted sediments, to explore the implication of spacial and temporal sampling programmes.The results obtained were not unexpected: there were spatial and temporal influences, sometimes so great that it would appear that you were examining samples from different parts of the country. However, data arising from solvent extracted sediments were found to be much less influenced by temporal sampling than by spatial variation. Another interesting and important observation was that sediment composition appeared to have no relationship to toxicant content.In this study, the first field application of the Mutatox test (genotoxicity) was carried out and it was found to be a very responsive test in all three types of samples. This test shows great promise as laboratory studies indicate it is sensitive to many of the chemicals which trigger the Ames test.