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 significant Cold War confrontation began in the Baltic. Its economic importance grew in the 1960s as surrounding countries began to exploit oil and gas resources. The largest environmental catastrophe in the North Sea was the destruction of the offshore oil platform Piper Alpha in 1988 in which 167 people lost their lives. Although de facto control of the North Sea played a decisive role in the political power relationships in north-west Europe since the time of the Vikings, and became a question of world politics after the First Anglo-Dutch War, until after the Second World War the bordering countries officially