The Contents of Heavy Metals in Long-Lived Mytilids from Ussuriisky Bay

The contents of heavy metals (HM) Fe, Cu, Mn, Zn, Cd, and Ni were determined in common species of long-lived mussels Crenomytilus grayanus (Dunker, 1853) and Modiolus kurilensis F.R. Bernard, 1983 from Ussuriisky Bay. Fe and Mn are indicators of the influence of terrigenous runoff; Cu and Zn, industrial and municipal waste pollution; and Cd and Ni, technogenic impacts. C. grayanus was sampled at eight stations, M. kurilensis was collected at one station (Cape Basargin); therefore, the HM content in organisms and the environment was mainly assessed from analysis of Gray's mussel samples. The current distribution of HM levels in mollusks of Ussuriisky Bay was generally more or less uniform. The concentration of Cu was only increased in Gray's mussel from Cape Telyakovsky, and increased Cd and Ni levels were found in mollusks collected from the pier of the port of Vera. In comparison with 2006, the upper values of the concentration ranges increased 1.5 times for Zn, more than 2 times for Cu, and almost 1.5 times for Cd. In mollusks from Lazurnaya Bay (a popular recreation site), the concentrations of Zn and Cu, tracers of anthropogenic impacts, increased by 10 and 20%, respectively. Since the mollusks studied are commercially valuable their HM content was compared with the maximum permissible concentration levels (MPCL). The content of Cd exceeded the MPCL in two specimens of Gray's mussels from the pier of the port of Vera and in a single specimen from Cape Sedlovidny.