A behavioural bioassay for impaired sea-water quality using the plantigrades of the common mussel Mytilus edulis L.: the response to copper

A bioassay has been developed, using the crawling and attachment behaviour of plantigrades of the common mussel, Mytilus edulis, for copper-impaired sea water. Potentiometric stripping analysis has been used to quantify the total and electrochemically labile species of copper. The threshold of sensitivity for the bioresponse lies between 13 ppb total, 8 ppb labile and 25 ppb total, 15 ppb labile copper, for a bioassay of 1 h duration. There is an example of hormesis for the bioresponse of the number of plantigrades that crawl for levels of copper at and below 13 ppb total, 8 ppb labile metal. The effects of light and gravity as directional cues and the effect of animal size and density in the bioassay have also been considered.