Toxicity of copper to two endemic Antarctic bdelloid rotifers <i>Adineta</i> sp. and <i>Habrotrocha</i> sp. (Bd14)

Past waste management practices and ongoing human activities at Antarctic research stations have resulted in contamination of terrestrial environments. Antarctic bdelloid rotifers are often endemic and biodiverse, inhabiting the ice-free areas that humans commonly occupy. Although waste and environmental management practices have improved, the impacts on native biota of exposure to contaminants, including metals, from legacy sources is largely unknown. To determine their sensitivity to copper, chronic toxicity tests of 28 days duration were performed on two endemic bdelloid rotifer species, Adineta sp. and Habrotrocha sp. (Bd14). Rotifer activity was dramatically reduced over the first 1 to 3 days of exposure, after which normal activity was observed through the continuation of their life cycle. Mortality increased with increasing exposure duration for the first 18 days of the test. Estimated lethal concentrations causing 50% mortality (LC50) were 227 and 170 µg L-1 Cu at 4 days and 104 and 68 µg L-1 Cu at 18 days for Adineta sp. and Habrotrocha sp. (Bd14), respectively. Reproduction in both species was impacted by exposure to Cu with 50% reduction in reproductive output (EC50) at 53 and 38 µg L-1 Cu at 28 days, respectively. Results from this project will be used to inform risk assessments at contaminated sites in Antarctica and can be used in the development of Antarctic-specific environmental quality guidelines.