In order to evaluate the capacity of mussels to accumulate pollutants and to enhance growth and physiological effects, an investigation was carried out in the Faroe Islands and in the Skagerrak. In March 2000, about 1500 mussels of proper dimensions (length ranging between 5 and 6 cm) were collected in the Kaldbak Fjord (Faroe Islands) on a 10m water column. Selected mussels were divided in 4 groups (320 each) and deployed in 4 different stations (one at the Faroe Islands and three in the Skagerrak). Semipermeable membrane devices (SPMDs) were also deployed in the same stations for the preconcentration of lipophilic pollutants. One month later (end of April-beginning of May) mussels and SPMDs were recollected and sent to different laboratories for the determination of various parameters.
Samples, mussels and SPMDs were analysed for the determination of PCBs, PAH and flame retardants concentrations, in order to assess bioconcentration factors in mussels. Only on mussel samples the determination of heavy metals was also performed. Before deployment at the different sites the mussels were individually marked at the edges of the shells which permitted measurement of shell growth. In order to find out any physiological effects in the deployed mussels measurements of energy budget "scope for growth", a method recomended by ICES, was performed. The measurements involved oxygen consumption, clearance rate, absorption efficiency and ammonia excretion were performed immediately after transportation from the field. In order to look for a connection between the health status and the water quality, the blood cell types have also been quantified and analysed with the help of a software image analysis. Also the gonadal condition were noted. Neutral red uptake assay, a method that uses the lysosomal membrane integrity in blood cells of the mussel Mytilus edulis as a biological indicator of water quality, was performed. A specific study to investigate a possible different activity of Cytochrome P450 1A1 in mussels, related to the area where the mussels were grown, was carried out.