Molluscan fisheries, constituted by bivalves, gastropods and cephalopods account for 11.6% of the world aquatic production. Mussels are widely distributed in tropical and temperate conditions, found typically attached to hard substratum with their byssus threads, in the intertidal and subtidal zones. This thesis encompasses the study on temporal and spatial variations in selected physicochemical parameters of the mussel beds along Dakshina Kannada, Karnataka, India. It deals with the investigations on selected trace metals and organochlorine pesticides in the shellfish waters, their bioaccumulation in the soft tissue of green mussels and the biomarker response in the mussels.Extent of faecal contamination of mussel beds is also presented. Results of the study indicate that organochlorine pesticides and trace metals in the shellfish waters of the study area were very low with the concentrations below the detectable limit and they are unlikely to result in any significant environmental imapacts on the health of the green mussel in the near future.
