Baltic Sea as species in 2005 and 2018 respectively, having formerly been confused with more widespread relatives. The tiny Copenhagen cockle ("Parvicardium hauniense"), a rare mussel, is sometimes considered endemic, but has now been recorded in the Mediterranean. However, some consider non-Baltic records to be misidentifications of juvenile lagoon cockles ("Cerastoderma glaucum"). Several widespread marine species have distinctive subpopulations in the Baltic Sea adapted to the low salinity, such as the Baltic Sea forms of the Atlantic herring and lumpsucker, which are smaller than the widespread forms in the North Atlantic. A peculiar feature of the fauna is that it contains a
History of the North Sea the main action was not in the North Sea but rather the Atlantic. Also different from the first war, the North Sea was no longer the exclusive territory of the Allies. Rather, it was, above all in the first years of the war, the stage for an intensive coastal war, featuring mainly small vessels like submarines, minesweepers, and Fast Attack Craft. However, despite early successes, which brought about a supply crisis in Britain, the Germans did not succeed in breaking the British resistance. Like in the first war, the allies soon controlled the seas, especially due to air superiority and