Baltic and Eastern Continental Rivers

The four major rivers that flow into the eastern Baltic Sea (the Vistula, the Nemunas, the Western Dvina, and the Narva) are described. All of these are lowland rivers. Most of the Vistula catchment is located in Poland, the Nemunas catchment-mainly in Belarus and Lithuania, the Western Dvina catchment-mainly in Russia, Belarus, and Latvia, and the Narva catchment-mainly in Russia and Estonia. The main human threats to these rivers are point and nonpoint pollution, water abstraction, flow regulation, and sediment loads. Several nonnative macroinvertebrate and fish species inhabit the basins. The largest cities near the rivers are Warszawa (at the Vistula), Kaunas (at the Nemunas), Riga (at the Western Dvina), and Pskov (at the Narva).