Biomonitoring of estuaries of the Peter the Great Bay (the Sea of Japan) using Corbicula japonica (Prime, 1864)

The estuaries of the Razdolnaya and Partizanskaya Rivers in the Peter the Great Bay were chosen to conduct the comparative studies of the effects of pollution on aquatic organisms. Corbicula japonica, a bivalve mollusk, was used as an indicator species. Molecular biomarkers in the digestive gland and gills of C. japonica were used to determine the indicators of oxidative stress, such as lipid peroxidation (malondialdehyde), antiradical activity, DNA damage and microelement composition of tissues. High concentrations of iron, zinc and lead were identified in the tissues of C. japonica from the Partizanskaya River. A high concentration of copper was found in the tissues of those from the Razdolnaya River. The level of lipid peroxidation products in the digestive gland of C. japonica from the Partizanskaya was higher than that of the other areas under study, Moreover, the level of antiradical activity and the genetic damage index in its tissues were two times higher. It is found that chronic oxidative stress is observed in all the estuaries under study. The proposed biomarkers clearly show the state of C. japonica in the biotopes of different pollution levels, indicating that the worst state is attributable to the estuary of the Razdolnaya River.