Clupea Clupea Clupea is genus of planktivorous bony fish belonging to the family Clupeidae, commonly known as herrings. They are found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of "Clupea" are recognized. The main taxa, the Atlantic herring ("Clupea harengus") and the Pacific herring ("Clupea pallasii") may each be divided into subspecies. Herrings are forage fish moving in vast schools, coming in spring to the shores of Europe and America, where they form important commercial fisheries. The species of "Clupea" belong to the larger family Clupeidae (herrings, shads,
Coastline of the North Sea have formed the Frisian Islands. In the micro tidal area, (a tidal range of up to , such as on the Dutch or Danish coasts, barrier beaches with dunes are formed. In the mesotidal area (a tidal range of between ), barrier islands are formed; in the macrotidal area (above tidal range), intertidal deposits raise the spring tide range . A soft rock coast is formed in the meso-macro tidal areas located in the southern North Sea. These soft rock coastal bedrock plains are interspersed with soft rock (shale and sandstone) cliffs. The small, historically strategic island of Heligoland was