Hydrologic input, nutrient and pollutant budgets, and biotic components of the North Caspian Sea

Title	Hydrologic input, nutrient and pollutant budgets, and biotic components of the North Caspian Sea
Publication Type	Conference Paper
Year of Publication	2003
Authors	Butler T.J., Tartowski S., Bashkin V., Lychagin M.Y., Sisengalieva G., Yergaliyev T.
Conference Name	17th Biennial Meeting of the Estuarine Research Federation
Date Published	September 2003
Conference Location	Seattle, WA
ARIS Log Number	160060
Abstract	The North Basin of the Caspian Sea is predominantly a shallow water estuary of the Volga River. The Volga River provides approximately 80% of the total riverine water input to the entire Caspian and represents the largest source of nutrients (N, P, and Si etc.) and pollutants (hydrocarbons, pesticides etc.). The Ural River also contributes inputs but on a much smaller scale, representing less than 5% of the riverine input to the Caspian Sea. In order to understand the ecological functioning and current status of the North Caspian, we will present hydrologic, carbon, organic and inorganic nutrient, and pollutant budgets impacting this rich estuarine system, as well as estimates of biomass and productivity of major components of the food web. These include phytoplankton, zooplankton and zoobenthic communities, invading species such as the comb jelly Mnemiopsis leidyi, several species of fish which are important both ecologically and commercially, and the endemic Caspian Seal. Comparing data collected during the Soviet era to more recent analyses, it appears that the North Caspian is less polluted today. However, illegal fishing has endangered some economically important commercial fish stocks such as the Beluga sturgeon (Huso huso) and, to a lesser extent, other sturgeon species.