Acid DNase activity in marine organisms displays a sensitive response to pollutants. In the present study, ex situ effect of toxic seawater organic extracts (Rijeka, Vranjic, Ploče) and in situ impact of environmental factors at referent (St. Andrew) and a polluted site (ACI Rovinj) on acid DNase in the digestive gland and gills of mussels was investigated. In the digestive gland, enzyme activity was related to potential toxicity of seawater organic extracts. Seawater organic extracts showed an increase of the enzyme activity in digestive gland following exposure. In in situ study, polluted environment affected mussel's acid DNase activity in digestive gland, when compared to gills. Acid DNase activity in the digestive gland expressed significant difference between the referent and polluted site, particularly from early spring through summer. Both ex situ and in situ studies displayed more sensitive acid DNase response to the presence of toxic mixtures in the digestive gland.
Keywords: Acid DNase; Environmental pollutant mixtures; In situ study; Mussel; Mytilus galloprovincialis.