Herring Herring Herring are forage fish, mostly belonging to the family Clupeidae. Herring often move in large schools around fishing banks and near the coast. The most abundant and commercially important species belong to the genus "Clupea", found particularly in shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea, as well as off the west coast of South America. Three species of "Clupea" are recognised, and provide about 90% of all herrings captured in fisheries. Most abundant of all is the Atlantic herring, providing over half of all herring capture. Fishes called herring are
Geology of the Baltic Sea in the early Holocene (ca. 10,000 years ago) glacier meltwater accumulated between the front of the ice sheet and the southern shores that were free of glacier ice. This accumulation of freshwater constituted a lake known as the Baltic Ice Lake. This lake did not mix with seawater from the west because the ground on the whole depression rose faster than sea level did. Eventually mixing and connection to the ocean did occur when the glacier front retreated to the north beyond Billingen about 11,500 years ago. The Baltic Ice Lake drained then rapidly reaching sea level. From this point