Trace metals in field samples of zooplankton from the Fram Strait and the Greenland Sea.

Trace metals (Cd, Pb, Ni, Cu, Zn and Hg) were evaluated in 14 zooplankton taxa collected on cruise ARK IX/Ib of RV 'Polarstern' to the Fram Strait and the Greenland Sea in March and April 1993. We found a substantial interspecific heterogeneity, e.g. with rather low Cd concentrations in calanoid copepods (0.1-0.7 mg kg-1, dry wt.) but remarkably high levels in the decapod Hymenodora glacialis (7-9 mg kg-1) and in the amphipods Themisto abyssorum and T. libellula (24-34 kg-1). In general, Pb was low (< 1 mg kg-1), while some enhanced Ni concentrations were found in the ostracod Conchoecia borealis (66-86 mg kg-1). A comparison to world-wide reported data on marine crustaceans did not reveal any suggestions on increased metal availabilities in both areas investigated, although one might expect a transport of some metals from Siberian rivers across the pole by the Transpolar Ice Drift Stream. However, more information on accumulation strategies of zooplankton under winter and summer conditions is necessary before a full assessment of metals in Arctic waters will be possible.