EROS-2000: After five years spent in the Gulf of Lions and the western Mediterranean, EROS 2000 moves east. West and east European scientists have decided to pool their efforts to study the Danube Delta and the north-western Black Sea. This area represents the ultimate example of deterioration of the coastal and marine aquatic environment. It can be viewed as the best pilot site to understand the complex interactions between human activities and the marine environment and the production of various biogases of climatological significance. The specific questions addressed by the project will be: What would be the consequences of a reduction of the river input of nutrients for the eutrophication and the ecosystem structure of the north-western Black Sea? What are the riverine and atmospheric sources, levels and fates of key organic/inorganic pollutants in the Black sea environment? What are likely to be the short-and long-term consequences of the regulation of river discharge for sediment transport/erosion/deposition and water stratification? What is the significance of the Black Sea source of important key greenhouse gases? This project will be restricted to the EROS 2000 participants from Ukraine and Russia. Existing biogeochemical data will be reviewed. Samples will be collected and chemical and radioisotopic analysis will be carried out. Reports will be produced mid-term and at the end of the project. A data file and a summary report will be prepared and the results will be published in international journals.