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
Migration of marine species in the Northern Atlantic Ocean from 1970-2006. Using fisheries data and computer models, Cheung was able to estimate the shift of species. Species are migrating north at an average rate of per decade. The study predicted that there will be a 60% shift of species towards northern waters within the next 41 years. Migration of marine species in the Northern Atlantic Ocean The world's oceans are warming due to climate change. Climate change is caused by three major factors which are the greenhouse effect, variation in the sun's energy that reaches Earth, and changes in reflectivity within Earth's atmosphere and its surface. The greenhouse effect