Spatial-temporal variability of mercury content in the river perch Perca fluviatilis Linnaeus, 1758 (Perciformes: Percidae) of the Rybinsk Reservoir at the turn of the XX–XXI centuries

Abstract

The amount of mercury (Hg) in the muscle tissue of the river perch (Perca fluviatilis Linnaeus, 1758) from different stretches of the Rybinsk reservoir was measured in a period from 1997 to 2012. Mercury concentrations were higher in muscles of perches from the Sheksna and Volga reaches, and lower in the Glavnyi and Mologa reaches, as well as Hg in bottom sediments from fish habitats. These values are shown to depend on the size of the fish and were found to increase in recent decades. The amount of mercury was determined in various organs and tissues of the perch. A positive correlation was established between the mercury content in all the studied samples and the mercury concentration in the muscle tissue in which it was the highest (up to 0.91 mg/kg wet weight). The bulk of the accumulated mercury present in the fish was found to be in the muscle tissue.

Keywords

• reservoirs
• accumulation of mercury
• bottom sediments
• ichthyofauna
• abiotic and biotic environmental factors