| Environmental problems in the Black Sea continue to be serious, even though governments have initiated a regional approach to the management and protection of the marine environment. Following the Chernobyl accident in 1986, the Black Sea riparian countries (viz., Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine) identified radioactive pollution as a serious problem. This paper presents some results of the project which is part of the fundamental research carried out by the P.P.Shirshov Institute of Oceanology of the Russian Academy of Sciences. The aim of the project is to develop the policy and methods for assessing the risk and fate of the Chernobyl radionuclides in the Black Sea.The risk assessment mathematical model has been designed to investigate the fate and distribution of the Chernobyl radionuclides in sediments of the Black Sea. One of the regions of intensive radioactive precipitation during the Chernobyl disaster was the nothwestern Black Sea region. There are some canyon systems in this region, where bottom sediments of the shelf zone are removed to the continental slope region and finally to the abyssal part of the sea. Occasionally there are dramatic velocity increases in the near-bottom current, the so-called ″bottom or benthic storms″. Different eddies above the area studied are supposed to be the cause of the observed events. In the following it is suggested that additional mechanisms are needed to explain some observations of bottom storms and mixing processes in the Black Sea. The importance of periodic bottom storms springs from the fact that they stir up bottom sediments with radionuclides incorporated, which are then captured and transported over large distances by weaker but stable currents. Some so-called ″warm″ bottom storms are connected with lutite flows, forming in the upper horizon of the slopes. This is due to bottom erosion, resulting from landslides and creeps of sediment, frequently shaken by local submarine earthquakes. As a result of this work scientifically provided recommendations have been elaborated for assessing risk of pollutants in the Black Sea and near-bottom dynamics interaction with the environment in natural and man-induced hazards and also suggestions for monitoring the near-bottom environment, aimed at minimizing negative ecological effects. The results of this work have confirmed once again by research that the Black Sea crisis calls for a concerted international approach and that it is critical for the future of the Black Sea that various programs addressing the Black Sea′s environmental problems be coordinated to work together. It will promote sustainable development of efforts towards improved environmental management and risk assessment in the Black Sea region. The results obtained for the Black Sea can be used in comparable regions of Russia for elaborating a policy, strategy and methodology of predicting the fate of pollution in the sea. Solution of these problems is particularly acute for the new social and economic conditions in Russia. |
|
|