Evaluation of a ?mussel watch? project for heavy metals in Scottish coastal waters

Results are presented of an extensive survey of the heavy metal content of intertidal mussels, Mytilus edulis (L.), from around the Scottish coasts. An important first conclusion is that areas can be identified in which mussels acquire relatively elevated concentrations of certain heavy metals. In general, areas of known pollution display elevated concentrations of several metals, but some areas not greatly influenced by man's activities also show elevated concentrations of a single metal. Comparisons are made of the strategies employed in this and other similar surveys and suggestions made for the design of future exercises.