Nature Conservation Research: Заповедная наука (Aug 2019)
Geographical variability of heavy metal concentrations in tissues of medical leeches (Hirudo medicinalis, Hirudo verbana) and in bottom deposit
Abstract
We present new data of the comparison of the geographical variability of heavy metal concentrations (Cu, Zn, Mn, Fe, Cd, Pb, Ni) in tissues of medical leeches (Hirudo medicinalis, Hirudo verbana) and in bottom deposit from places of their inhabitation in various regions of Russia and Ukraine. The geographical factor was found to have a significant impact on the elemental status of medical leeches and bottom sediments. It was shown that, irrespective of geographic and biotopic timing, both types of medicinal leeches are macroconcentrator Zn and deconcentrator Mn and Fe. A high cumulative activity of H. medicinalis and H. verbana in relation to ecotoxicants Cd, Pb and Ni in aquatic ecosystems of industrial regions was revealed. A decrease in bioaccumulation activity towards heavy metals in specimens of medical leeches living in adverse climatic conditions on the northern and eastern borders of the range is shown. The ability of leeches H. medicinalis and H. verbana to regulate the level of essential metals Mn and Zn in the body is established, while the content of Cu, Fe, Cd, Pb, Ni is determined by the concentration of these elements in the habitat (bottom sediments). A high variability of the studied parameters and the general laws of bioaccumulation activity of leeches in relation to heavy metals are caused of significant correlation with climatic and geographical features of the studied regions, and a degree of anthropogenically modified territories. It is shown that the microelemental status of leeches as a whole objectively reflects regional specificity of the ecological conditions of hydrobiocoenosises. Thus, the performed investigation can be used in monitoring actions for preservation of water resources and protection of natural biological resources of the hirudofauna.
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