Recent taxonomic discoveries concerning the mussel mytilus : implications for biomonitoring

Mytilus edulis is the most commonly used bioindicator for marine pollution. Recent taxonomic findings based on studies of allozyme variation had shown that the species consists of 3 separate evolutionary lines and of 3 separate species Mytilus edulis, Mytilus galloprovincialis and Mytilus trossulus. Specimens of M. edulis and M. trossulus from the same habitat were compared for concentrations of 25 elements using inductively coupled plasma mass spectrometry. M. trossulus had higher element concentrations than M. edulis. The differences were related to differences in growth rate; these differences could be corrected by standardizing the mussels to a fixed width/height ratio.