Influence of body length, life-history status and sex on trace metal concentrations in selected zooplankton collectives from the Greenland Sea

An important pre-condition for using aquatic invertebrates as biomonitors is a quantification of their biological attributes or life-history traits on trace metal levels accumulated under field conditions. In the present study we report data obtained for the amphipods Themisto libellula and T. abyssorum and the copepod Calanus hyperboreus from the Greenland Sea. Regarding T. libellula we obtained exponential relationships between Cd, Pb, Cu and Ni concentrations and their body length, while for Zn no length dependency was noted. Further, substantial differences between juveniles from the marsupium versus adults were recorded for both amphipod collectives investigated (0.06–0.21 vs 26–50 mg Cd kg−1 dry wt and 3 vs 26–37 mg Cu kg−1). Significant differences were also noted for copepods, with juveniles showing, for example, somewhat enhanced Cd levels, but they were not as pronounced as those for amphipods (0.54–0.67 vs 0.94 mg Cd kg−1). Results are discussed focussing on potential for trophic transfer and on metabolic requirements. Finally, we recommend utilization of only adult individuals in routine biomonitoring studies.