Abstract
Rivers are among the main sources of marine litter, especially for semi-isolated sea areas with high populations and intense economic activity. The semi-isolated Black Sea located in the Eastern Europe is an example of such an area, whose watershed basin is under high anthropogenic pressure. In this study, we report the results of the first long-term monitoring program of floating litter at several rivers inflowing to the northeastern part of the Black Sea. We describe the main characteristics of registered marine litter, including the distribution of its type and size. Based on the obtained results, we reveal the relation between river discharge rate and the litter flux for the considered rivers. Using this relation extended to all rivers of the study area, we assess the total annual flux of riverine litter to the northeastern part of the Black Sea.