TY JOUR TI MIGRATION OF SELENIUM IN AQUATIC ECOSYSTEMS OF THE VOLGA RIVER WITHIN THE BORDERS OF THE SARATOV REGION KW aquatic ecosystem KW migration of selenium KW macrophytes KW plankton and benthic forms KW mollusks KW carp species JO Vestnik of Astrakhan State Technical University. Series: Fishing industry AU Smutnev, P.. AU Pudovkin, N.. PY 2016 IS 2016 PB Astrakhan State Technical University