TOTAL UNSATURATED-COMPOUNDS AND POLYCYCLIC AROMATIC-HYDROCARBONS IN MOLLUSKS COLLECTED FROM WATERS AROUND NEWFOUNDLAND

Baseline concentrations of total unsaturated compounds extracted from six species of molluscs, collected from waters around Newfoundland and Labrador were determined by ultraviolet/fluorescence spectroscopy (uv/f, chrysene equivalents, IOC recommendation). Extracts of muscle tissue from scallops, Placopecten magellanicus, clams, Mya arenaria, whelks, Buccinum undatum and propeller clams, Cyrtoderia siliqua had negligible hydrocarbon concentrations compared to the corresponding visceral mass. The pattern of concentration (GC-MS) of the 16 PAH priority pollutants (EPA recommendation) was similar in the visceral mass of these species and in whole mussels (Mytilus edulis) and periwinkles (Nucella lapillus). When the 16 PAH were detected (>5 ng/g, dry weight), fluoranthene dominated (<200 ng/g), followed by phenanthrene-anthracene (<50 ng/g). Extracts of the visceral mass of scallops appeared to contain a relatively larger amount of uv/f absorbing hydrocarbons; therefore, a further investigation was undertaken. A C-25 unsaturated hydrocarbon of molecular weight 346 was identified as the major component of the extraction mixture. Overall, hydrocarbon levels were very low in comparison to other geographical regions.