Oral Presentation Society of Environmental Toxicology and Chemistry Australasia 2023

Environmental Protection of sub-Antarctic Macquarie Island: Derivation and application of site-specific Environmental Guidelines for soils at remediated fuel spill sites. (#96)

Catherine K King 1 , Jane Wasley 1 , Jeremy Richardson 1
  1. Australian Antarctic Division, Kingston, TAS, Australia

To ensure effective restoration and environmental protection of fuel spill sites on Macquarie Island that have undergone remediation, the Australian Antarctic Division has developed site-specific Environmental Quality Guidelines and Remediation Targets. Contemporary best practice ecotoxicological and statistical modelling methods, following Australia/New Zealand Water Quality Guidelines and the National Environmental Protection Measure were used. This body of work includes compilation of more than a decade of ecotoxicology research that has produced a comprehensive suite of toxicity tests for a representative range of native biota, including invertebrates, plants and soil microbes. Tests were conducted using a range of soil conditions, representative of that found on the island (fresh to aged diesel fuel and wide soil carbon range). The most robust and representative sensitivity data were selected using expert judgement for incorporation into a cumulative species sensitivity distribution (SSD) model. From this model, we quantitatively estimate Protective Concentrations for fuel at levels appropriate to the ongoing land use status. Our results estimate that protection of 90% of biota requires concentrations of total hydrocarbons (TPH) not exceed 72 mg TPH/kg soil. A less conservative level of 80% protection (achieved at 140 mg TPH/kg soil) is considered more appropriate for impacted areas and was used in the assessment of ongoing risk of remediated soils within the station footprint. These site-specific Remediation Targets for Macquarie Island directly inform site management and may be suitable for the broader subantarctic region.