A field course survey of three English river systems

A hydrobiological field course for undergraduates in the Department of Biology, University of Salford has proved useful in investigating river pollution, and parts of the course may be suitable for upper school studies. The course compares the Lancashire rivers Lune, Ribble and Irwell, but could be adapted for still waters. The water quality was assessed by simple chemical methods and the bacteriological quality by multiple tube and membrane filtration techniques. These assessments were then related to the benthic inverte-brates in the rivers—dipteran larvae, oligochaete worms, leeches, molluscs, stoneflies and mayflies. The Irwell was found to be grossly polluted, the Ribble mildly polluted and the Lune relatively unpolluted.