Microelements and Heavy Metals in the Muscles of the Muskrat (Ondatra zibethica) from the Selenga River Delta

摘要

The Selenga River accounts for more than half of the total flow discharge to Lake Baikal. The extensive delta of this river with a total area of 780 km~2 is the region of reproduction and fattening of fish, birds, and the muskrat. The muskrat (Ondatra zibethicus) was brought to Transbaikalia from Finland in 1932. Today, its population in the wetlands of the Selenga River delta is most abundant in the Buryat Republic and yields up to 50 percent of the pelts procured in the region (Pronin et al., 1983). The long-term practice of muskrat breeding in the republic has shown that the natural population growth within the range of biological potential of this species depends not only on fluctuations of water supply to the wetlands and the epizootic situation (Pronin et al., 1983), but also on other factors, including the effects of pollutants on the state of biocenoses. Until recently, the biogeochemical situation in the Selenga River delta was poorly understood (Breslav and Taganov, 1978; Vetrov and Belova, 1979). Information on the element composition of vertebrates, including the muskrat, was lacking, although data on the concentrations of heavy metals and trace elements in aquatic animals could be used for comprehensively monitoring the ecological situation in water bodies and streams.