Caspian Sea 2011

2010

River input Volga River

bons and chlorinated pesticides (DDT, and DDE). Whereas the annual discharge of some compo- nents (detergents, phenols and copper) has re- mained relatively unchanged, the flux of zinc has apparently doubled in recent years. In1977-1993 average annual loads of DDT and DDE were 3,710 kg and 1,320 kg respectively. Katunin et al. (2003, 2005, 2006) has estimated phosphorus and nitrogen loading from the Volga River. As Volga River represents the major water in- flux, it also indicates themain tendency of the whole region. Remarkable increase in the phosphorus and nitrogen loads was detected after 2000. Kura River In 2005, a pilot study was conducted in the Kura River, with a survey undertaken at seven sites from the Mingechaur Reservoir to the Kura River Delta. Although profond conclutions were difficult to determined, the study revealed that a wide range of elements such as As, Cd, Cr, Cu, Hg, Mo, Ni, Pb, and Zn had concentrations al- ways below the respective Maximum Contami- nant Level (MCL). Measurable levels of PAHs, PCBs, and several chlorinated pesticides were often, but not always, detected (CEP 2005). A radiological survey of the Kura and Araks River system in Azerbaijan conducted in 2005 by the Inter- national Atomic Energy Agency reported about ac- tivity of several radioisotopes ( 137 Cs, 238 U, 234 U, 240 Pu, 238 Pu, 90 Sr and 241 Am). They were measured in sedi- ment samples and some aquatic plants. The values obtained for the radionuclide levels in the freshwa- ter sediments were relatively low, and in most cases below the detection limit. Available information re- flects that radionuclides are natural and/or related to known atmospheric inputs (Shaw, at al., 1998). Terek River The data on Terek River refers to “A Desk Study Project to Determine the Fluxes of Major Con- taminants from the Terek River into the Caspian Sea” accomplished in 2007. Historical data sets about water quality are sparse and official data for water discharge statistics in the Terek River re-

Rivers are reported to be the main source of wa- ter pollution entering the Caspian Sea, however reliable data characterizing the concentration and sources of this pollution remains limited. Much of the available data was collected in the 1990’s and concentrations reported for a number of param- eters are highly variable, indicating perhaps differ- ent methodologies and analysis techniques. In 1994, Bukharitsin and Luneva reported that more than 23 km 3 of wastewater and industrial wastes containing approximately 387 thousand tonnes of suspended sediments entered the Cas- pian Sea from Volga River each year. As mentioned the bulk of the flow in the Volga River has been highly regulated by a series of hydro-engineering constructions since 1955. This flow regulation has changed the spring- summer flood regime, which is the main influence on transport of sediment into the Volga Delta. Studies indicate that the over a pe- riod of 1978-1991, 8.9 million tones of suspended solids per year on average entered the delta, at average water turbidity 33 g/m 3 . In 1992-2004 the average flow of sediments constituted 5.9 million tones per year, while average turbidity reduced down to 22 g/m 3 . Research carried out in 1997 by the Russian Academy of Sciences showed that a significant amount of the heavy metals in the wa- ters of the Lower Volga were transported on sus- pended solids (CEP, 2006 b). In 2006, «The Study and Review for Determination of Major Pollutants Flow from the Volga Cascade» estimated and summarized annual fluxes at differ- ent parts of the delta for some key pollutants. These averages are calculated for three zones of the Volga River delta, namely at the apex and the shoreline (DSL) at the western and eastern delta fronts. The fluxes of pollutants vary. The western part usually receives 60-70% of flow, except for lindane ( γ -HCH), which is more prevalent in the eastern discharge. Comparison of data from the period 1995-2004 to those from 1977-1993 illustrates significant declines in the fluxes of petroleum hydrocar-

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