Significance and interspecific variability of accumulated trace metal concentrations in Antarctic benthic polychaetes

Trace metals were analysed in polychaetes collected on Polarstern cruise ANT XXI/2 (2003/04) to the Weddell Sea. Pb concentrations were largely less than 1.3 mg kg−1 DW in all samples analysed. Statistical results indicate that the accumulated Cd, Cu and Zn concentrations are related to the feeding guild to which the animals are belonging. Relatively low Cd and Cu concentrations are found in macrophagous carnivores and relatively high concentrations in microphagous detritus feeders. The relationship between Zn concentrations and the feeding guilds of polychaetes is reverse. Cd concentrations range from (median values and interquantile ranges in brackets) 2.6 (1.5–3.2) mg kg−1 DW in the carnivorous Trypanosyllis gigantea to 133 (37–176) mg kg−1 in the microphagous detritus feeder Lanicides bilobata; Cu concentrations from 16 (11–19) mg kg−1 in the carnivorous Antarctinoe spicoides to 40 (23–68) mg kg−1 in the microphagous detritus feeder Phyllocomus crocea and Zn from 89 (69–97) mg kg−1 in the microphagous detritus feeder Isocirrus yungi to 396 (372–404) mg kg−1 in the carnivorous Aglaophamus trissophyllus. Ni is ranging from 3.7 (1.8–6.0) mg kg−1 in Polyeunoa laevis to 34 (20–41) mg kg−1 in A. spicoides, but no significant differences are obvious regarding the feeding guilds. Since information on metals in Antarctic polychaetes is almost completely lacking, our results suggest further studies to clarify the role of feeding in the bioaccumulation of metals in this ecologically important taxonomic group.

Research Highlights
► First information on trace-metal concentrations in polychaetes from the Weddell Sea.
► Low Cd and high Zn concentrations in macrophagous carnivores.
► High Cd and low Zn concentrations in microphagous detritus feeders.
► Comparison to worldwide reported data on metals in polychaetes.
► Evidence for hyperaccumulation of Cd and Ni in some polychaete species.