Objective: To evaluate the potential local benthic biomonitor organism, Orchomenella pinguis (O. pinguis), for mining contamination by addressing accumulation and toxicity of mining related metals in this arctic marine amphipod. Methods: A toxicity study exposed O. pinguis to four commonly occurring heavy metals (Cd, Cu, Zn and Pb) associated to the mining industry in Greenland using: 1) a 5-day water-only bioassay; 2) a water-only bioassay evaluating the response between metal accumulation in O. pinguis and metal concentrations in water during a 5-day period; and finally 3) a sediment bioassay evaluating the response between metal accumulation in O. pinguis and metal concentrations in sediment as a function of time during a 20-day period using different mixtures of mining-contaminated sediments. Results: LC50 values for the four metals were 2.8, 5.4, 10.4 and 21.4 µmol/L, for Cu, Cd, Pb and Zn, respectively, with corresponding modelled metal concentrations of 3.4, 1.0, 11.1 and 6.1 µmol/g dry weight. During the sediment exposure experiments, a similar concentration of Zn did not induce lethal effects at the same level. Conclusions: This study demonstrates that the appliance of metal organism concentrations as an estimate of effects is not a sufficient biomonitor of environmental effects. The organism may sequester metals into cellular compartments thus rendering the metals inert for toxic effects. More studies are needed to investigate effects of metal bioavailability. Additional biomarkers such as effects on functional responses e.g. feeding and burial behavior or effects on reproductive success are suggested in order enhance to the ecological significance.
|Journal||Journal of Coastal Life Medicine|
|Publication status||Published - 28 Feb 2014|