Variations in the Heavy Metal Contents in Tissues of the Sea Cucumber Eupentacta fraudatrix in the Coastal Waters of the Sea of Japan: the Influence of Physiological and Anthropogenic Factors

Abstract—Data on temporal (July and September) and interannual variations in the content of several heavy metals are presented for the body wall, gonad, and gut of the sea cucumber Eupentacta fraudatrix from coastal waters of two inlets of Peter the Great Bay (Sea of Japan) with different levels of anthropogenic pollution. The gonads mostly accumulate Zn, Fe, Cu and Cd, while the body wall, presumably, Mn and Pb. Moreover, an increase in the heavy metal content in the gut below a certain threshold is asynchronous with changes in the content of most of them in the body wall and/or gonads, which are caused mainly by physiological factors during the spawning period. However, the influence of environmental pollution is significant during the postspawning period. When the heavy metal content in the gut exceeds a certain limit, synchronous variations in concentrations of heavy metals in the gut and tissues were recorded, which highlight impaired control of the heavy metal distribution in the organism. A correlation between the lead content in the gut and gonad indicates the possibility of determining this metal in the gonads as a bioindicator of environmental pollution.