The occurrence of the copepods Stephos longipes (Calanoida) and Drescheriella glacialis (Harpacticoida) in summer sea ice in the Weddell Sea, Antarctica

In January to March 1997, a RV Polarstern cruise that transected the Weddel l Sea resulted in samples being taken in thick pack ice in the south-easter n Weddell Sea and then along the marginal ice edge towards the Antarctic Pe ninsula. Several ice types were thus sampled over a wide geographic area du ring late summer/early autumn. Common features of the first warm period was the occurrence of surface ponds, and that many floes had quasi-continuous horizontal gaps, underlying a layer of ice and metamorphic snow. With the o nset of cold air temperatures in late February the gaps rapidly refroze. Th e calanoid copepod Stephos longipes occurred in all habitats encountered an d showed highest numbers in the surface ice in summer, in the gap water dur ing both seasons and in the refrozen gap water in autumn. Nauplii outnumber ed copepodids in the surface ice and refrozen gap water, while in the gap w ater copepodids, mainly stages CI-CIII in summer and CII-CIV in autumn, com prised about 70% of the total population. The harpacticoid species Drescher iella glacialis did not occur in all habitats and was missing in surface po nds and new ice. Nauplii of D. glacialis were rarely found in gap water, bu t predominated in the refrozen gaps.