Histopathological changes related to chemical contamination in Mytilus edulis from field and experimental conditions

Abstract

ABSTRACT: This comparative histopathological study, carried out at the GEEP Workshop, assesses tissue changes in mussels Mytilus edulis from a contaminated Norwegian fjord and from mesocosm basins where a contaminant gradient had been simulated. Parasitism by larval trematodes was observed in both circumstances, but was not related to contaminant levels. Mussels from the field exhibited granulocytomas in their interstitial tissues, with a greater incidence at polluted sites than at a reference site, suggesting that granulocytomas could be a consequence of chronic pollutant exposure. This pathological condition was not observed in experimentally treated mussels, which nevertheless had severe tissue alterations, especially in digestive tubules and gills, under exposure to high levels of a diesel oil and copper mixture. It is concluded that this type of histopathological analysis can provide useful information on the health of mussels, and that this information can be used successfully in the comparison of field samples. INTRODUCTION