Measuring and assessing the risk of metal contaminants in the Antarctic nearshore marine environment

ANTARCTICA is generally considered to be pristine; however, localised contamination around research stations is causing disturbances in the nearshore marine environment. Mixtures of metal contaminants enter the nearshore marine environment by leaching from historical waste during summer ice-melt events, in station wastewater discharge, and from anthropogenic activities such as fuel burning. To address these and other human impacts, the Protocol on Environmental Protection to the Antarctic Treaty System came into force in 1998 and required more stringent environmental management practices from nations, such as cleaning up historical waste and limiting the impact of anthropogenic activities. Despite being in place for 20 years, very few waste sites have been remediated across the continent and environmental management practices lack defined guidelines and benchmarks. Hindering good environmental management practices is the lack of Antarctic-specific environmental quality standards and contaminant monitoring tools. Organisms in the Antarctic marine ecosystem have unique adaptations to their cold environment which may influence their sensitivity to contaminants; including, longer developmental times, high lipid contents, and slower metabolic rates. These differences mean that ecotoxicological data needs to be generated using native Antarctic organisms to ensure environmental quality standards will protect the unique ecosystem. These standards also need to consider the risk of contaminants in mixtures, and the potential for toxicity from a variety of exposure pathways. Environmental quality standards should be supported by contaminant monitoring tools that account for the high variability in contaminant concentrations over time as well as environmental factors that may modify contaminant toxicity. This thesis investigated the toxicity of five common metal contaminants (cadmium, copper, nickel, lead, and zinc), singly and in mixtures, to two Antarctic marine microalgae...