Recent Tendencies Characterizing the Populations of Margaritifera margaritifera and the Results of Activities on their Conservation and Restoration

Abstract

One of the largest pearl mussel populations in the study area, that in the Peipia River, was observed from 2008 to 2014. It was found to be affected by several negative impacts such as the extermination of host fishes, pollution, beaver dams, and, finally, direct extermination of the habitats and the molluscs during the construction of new electric power line. The number of pearl mussels reduced from 40,000 to 25,000, and further decline is expected. The other two rivers, the Gladychevka and the Roshinka, were observed from 2006 to 2011. There were several dozens of pearl mussels in them. Salmon parrs had been released in these rivers. According to the performed assessment, a release of several thousand salmon parrs in a pearl mussel habitat during optimal season may be expected to result in the survival of several juveniles of pearl mussels. A more definite conclusion cannot be made.