The scope of this program is the estimation of pollution in Thermaikos Gulf using cellular and molecular biomarkers in tissues of mussels. Mussels Mytilus galloprovincialis were collected from 4 stations in Thermaikos Gulf and one station in Strymonikos Gulf (Fig. 1) every six months. Mussels were sampled from Aggelochori (cultured population), Peraia (natural population), from a natural population located near the Outlet tube of the sewage treatment plant of Kalohori, as well as from cultured populations in Halastra. Mussels were also sampled from a cultured population in Olympiada located in Strymonikos Gulf, which was selected as a reference station. The biomarkers which were evaluated in the digestive gland of mussels were
