Calculation of the Assimilation Capacity of the Volga River Estuary Area Using the Example of Heavy Metals

Abstract

The purpose is to obtain the value of assimilation capacity and assess the state of the ecosystem of the Volga estuary territory by its importance. Materials and methods. The data for the study were the results of monitoring conducted by the Federal Service for Hydrometeorology and Environmental Monitoring in 2012-2014 in the Russian sector of the Caspian Sea. The assimila tion capacity was calculated using the method proposed by Yu.A. Israel. To calculate the reserve coeffi cient, the maximum permissible concentrations values or the average values obtained from the open database on the toxic eff ects of chemical substances on living organisms ECOTOX were used. The estimation of the amount of pollution time in the ecosystem was carried out based on hydrodynamic conditions. The current velocity at the initial section of the estuarine seaside was taken from the operational model of the Federal Service for Hydrometeorology and Environmental Monitoring. Results and discussion. The calculations revealed that the assimilation capacity values for toxic metals (lead, cadmium, mercury) are signifi cantly lower than the assimilation capacity values for essential metals (iron, copper, zinc, nickel). A compar ison of the assimilation capacity with the average long-term fl ow of the studied metals by the Volga showed that the assimilation capacity value in most cases is signifi cantly higher than the value of metals input to the northern part of the Caspian Sea. Conclusion The obtained values of the assimilation capacity levels of the Volga estuary for heavy metals indicate that the current infl ux of metals does not cause signifi cant damage to the ecosystem under study.