Zooplankton is mostly copepods "Calanus finmarchicus" and "Calanus hyperboreus". "C. hyperboreus" is strongest in the Arctic waters. They are the main diet of most marine predators. The most important krill species are "Meganyctiphanes norvegica", "Thyssanoessa inermis", and "Thyssanoessa longicaudata". In contrast to the Greenland Sea, there are a lot of calcareous plankton (Coccolithophore and Globigerinida).