Metal uptake and toxicity to freshwater algae: From the laboratory to the field
TUESDAY, JANUARY 31, 2012 - 3:30 PM IN EIT 3142 AT THE UNIVERSITY OF WATERLOO
Abstract:
Within the biotic ligand model (BLM) construct, major cations are considered to be simple competitors for metal binding to uptake sites and may offer some protection against metal-induced toxicity, but the influence of essential trace elements on metal uptake and toxicity is considered to be negligible. We recently showed however that a 100-fold increase in [Zn2+] and [Co2+] from 10-11 to 10-9 M significantly decreased Cd2+ uptake and toxicity in Chlamydomonas reinhardtii by more than 2-fold. Low essential trace metal concentrations may thus strongly affect the uptake and toxicity of cadmium in freshwater algae. Such findings imply that the prediction of metal uptake by algae in natural systems where many species are present is likely to be challenging. Yet, the response of natural periphythic algal communities to chronic metal contamination downstream from an abandoned mine tailings site showed highly significant relationships between intracellular metal and calculated free metal ion concentrations.