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
Ports of the Baltic Sea Ports of the Baltic Sea There are over 200 ports in the Baltic Sea. When only those ports that handle a minimum of 50,000 tonnes of cargo annually, and where at least part of this cargo is international are taken into account, the number of ports reaches approximately 190. In 2008, the total amount of cargo handled in the Baltic Sea ports amounted to 822.4 million tonnes, which was 0.4 per cent less than in 2007. Primorsk, Saint Petersburg and Muuga were the biggest ports in the Baltic Sea in 2008. Together the three top ports handled over one fifth