<P> Since the end of World War II, various nations, including the Soviet Union, the United Kingdom and the United States, have disposed of chemical weapons in the Baltic Sea, raising concerns of environmental contamination . Even now fishermen accidentally retrieve some of these materials: the most recent available report from the Helsinki Commission notes that four small scale catches of chemical munitions representing approximately 105 kg (231 lb) of material were reported in 2005 . This is a reduction from the 25 incidents representing 1,110 kg (2,450 lb) of material in 2003 . Until now, the U.S. Government refuses to disclose the exact coordinates of the wreck sites . Rotting bottles leak Lost and other substances, thus slowly poisoning a substantial part of the Baltic Sea . </P> <P> After 1945, the German population was expelled from all areas east of the Oder - Neisse line, making room for displaced Poles and Russians . Poland gained most of the southern shore . The Soviet Union gained another access to the Baltic with the Kaliningrad Oblast . The Baltic states on the eastern shore were annexed by the Soviet Union . The Baltic then separated opposing military blocs: NATO and the Warsaw Pact . Had war broken out, the Polish navy was prepared to invade the Danish isles . This border status restricted trade and travel . It ended only after the collapse of the Communist regimes in Central and Eastern Europe in the late 1980s . </P> <P> Since May 2004, with the accession of the Baltic states and Poland, the Baltic Sea has been almost entirely surrounded by countries of the European Union (EU). The only remaining non-EU shore areas are Russian: the Saint Petersburg area and the exclave of the Kaliningrad Oblast . </P> <P> Winter storms begin arriving in the region during October . These have caused numerous shipwrecks, and contributed to the extreme difficulties of rescuing passengers of the ferry M / S Estonia en route from Tallinn, Estonia, to Stockholm, Sweden, in September 1994, which claimed the lives of 852 people . Older, wood - based shipwrecks such as the Vasa tend to remain well - preserved, as the Baltic's cold and brackish water does not suit the shipworm . </P>

Which major russian city borders the baltic sea