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
Islands of the North Atlantic one of the regions which appoint a representative onto the committee of the World Universities Debating Council. Greenland, the Faroe Islands and Iceland would be included in the definition of IONA used in this context, while Newfoundland and Prince Edward Island would be in North America. However, none of these islands have yet participated in the World Universities Debating Championships. Otherwise, the term has achieved very little popular usage in any context. Islands of the North Atlantic IONA (Islands of the North Atlantic) is an acronym suggested in 1980 by Sir John Biggs-Davison to refer to a loose linkage of