Fauna of Europe of the Baltic Sea has led to the evolution of many slightly divergent species, such as the Baltic Sea herring, which is a smaller variant of the Atlantic herring. The most frequent benthic species are "Saduria entomon" and "Monoporeia affinis", which is originally a freshwater species. A great part of its bottom is anoxic and without animal life. The Baltic Sea and North Sea are also home to a variety of marine mammals (common seals, grey seals). Europe contains several important freshwater ecoregions, including the heavily developed rivers of Europe, the rivers of Russia, which flow into the Arctic, Baltic,
History of the North Sea dumped in the Skagerrak and the Baltic, conventional weapons (grenades, mines, bazookas, and cartridges) were sunk in the German Bight. The estimates vary widely but it seems to be clear that more than a hundred thousand tons of munitions were sunk. The Maunsell Sea Forts were small fortified towers built in the Thames and Mersey estuaries during the Second World War to help defend the United Kingdom. One of which on HM Fort Roughs is now occupied by the controversial Principality of Sealand. Post Second World War period, the North Sea, bounded entirely by NATO allies became completely peaceful whilst