Evidence for environmentally derived immunomodulation in mussels from the Venice Lagoon

Abstract

Mussels, Mytilus galloprovincialis, were sampled at three times of year, from various sites within the Venice Lagoon and a reference Platform site in the north Adriatic. The immune response of the mussels was assessed using a range of assays which included total and differential cell counts, phagocytosis, degradative enzyme levels and release of reactive oxygen metabolites. Chlorinated hydrocarbons, including lindane, DDT and PCBs, together with trace metal levels were measured in digestive gland tissues from the mussels. The measurements of immune response and the contaminant levels showed seasonal fluctuations. However, the results did demonstrate significant differences in a number of immunocompetence assays which in some instances showed some correlation with the levels of contaminants measured in the tissues. In particular, total and differential cell counts, phagocytosis and release of reactive oxygen metabolites showed a degree of correlation with contaminant burdens although other factors were clearly involved. The results confirm the requirement for using a range of assays for monitoring pollution effects.