Topography of the Arctic Ocean

Polymastiidae (Porifera: Demospongiae) of the Nordic and Siberian Seas

“…The impact of the freshwater inflow, the ice movements and the summer heating is especially severe in the large shallow-water areas along the coast. The bottom here comprises spacious plains covered with mud and clay (Herman, 1974;Weber, 1989). Due to the unstable environment, both in the water body and on the seabed, the biodiversity, especially the diversity of sessile macrobenthos, of these areas is considerably poorer than along the coasts of the Nordic Seas (Golikov & Scarlato, 1989).…”

“…On the contrary, in the offshore areas of the Siberian Seas the salinity is more stable, a branch of the Atlantic current brings warm water to the deep (Coachman & Aagaard, 1974), and the northern coast of large offshore archipelagos, e.g. Severnaya Zemlya and New Siberian Islands, is characterized by the rock cliffs and steep slopes running to great depths (Herman, 1974; Weber, 1989). These areas are oases hosting a relatively rich bottom fauna, particularly some diverse sponge communities (Golikov et al ., 1990).…”