Abundances of the life stages of zooplankton taxa were calculated in the Arctic Ocean during Polarstern cruise ARK-II/2. Samples were collected in vertically hauled nets with a Multinet midi (Hydrobios, Kiel), which is equipped with five nets (mesh size: 200 µm). The water volume filtered was measured with a flowmeter attached in the net. Further details on sampling and analysis methodology can be found at Smith et al. (1986). The zooplankton samples were taken as part of the international Marginal Ice Zone Experiment (MIZEX) that was designed to study the atmospheric, oceanic, and ice interactions in the Fram Strait region of the Greenland Sea.