Using an expert judgment response matrix to assess the risk of groundwater discharges from remediated fuel spill sites to the marine environment at sub-Antarctic Macquarie Island, Australia

Residual contamination from remediated fuel spill sites at Macquarie Island poses minimal risk to adjacent marine communities, according to a comprehensive toxicity assessment. The study, using an expert judgment response matrix, found that even under worst-case exposure conditions—undiluted and continuous—native marine invertebrates showed variable and slow responses, with some species exhibiting no adverse effects. Natural site dynamics, such as rapid dilution due to high rainfall and energetic receiving environments, further mitigate potential risks. While toxicity was observed in certain species over extended periods (up to 21 days), no consistent patterns linked to hydrocarbon concentrations were identified. This research provides robust evidence that residual groundwater contamination at remediated sites is unlikely to harm marine ecosystems, offering critical insights for environmental risk assessment in sub-Antarctic regions.

King, C. K., Wasley, J., Holan, J., Richardson, J., & Spedding, T. (2020). Using an expert judgment response matrix to assess the risk of groundwater discharges from remediated fuel spill sites to the marine environment at sub-Antarctic Macquarie Island, Australia. Integrated Environmental Assessment and Management, 17(4), 785–801. https://doi.org/10.1002/ieam.4382