MEPS 289:201-213 (2005)  -  doi:10.3354/meps289201

ABSTRACT: Assessments of the potential for metal and radionuclide contamination of arctic organisms have been based in part on experiments on organisms collected from temperate zones, even though adaptation to Arctic environments may enhance bioaccumulation of contaminants. Here, we compare the potential for blue mussels Mytilus edulis originating from the Arctic and from temperate zones to accumulate trace metals from filtered algal food at 2 temperatures. Geographic origin had little effect on either the percentage of metal assimilated from food (the assimilation efficiency, AE) or the rate at which ingested metal was excreted (measured by the efflux constant, k_e). By comparison, experimental temperature had much larger effects, causing AE for Ag, Am and Zn to be 122 to 945% higher, and k_e for Cd and Co to be 50 to 80% lower at 2°C than at 12°C. The effect of temperature on the trophic accumulation factor (TAF = AE/k_e) was even more pronounced and systematic, with all metals characterized by larger TAFs at 2°C than at 12°C. The effects on the TAF were largest for the non-essential metals Ag and Am (6 to 7-fold), smallest for the required elements Co, Se and Zn (2 to 3-fold) and intermediate for Cd (4-fold). Geographic origin affected the TAF for Cd only, with temperate mussels displaying slightly higher potential for biomagnification. Our study suggests that, with the exception of Cd, mussels from temperate and Arctic zones accumulate metals from food similarly, and that temperature has a much larger impact on accumulation than population origin.

KEY WORDS: Metals · Dietary uptake · Bioaccumulation · Temperature · Arctic · Mytilus · Assimilation efficiency · Efflux constant