Assessment of contamination by heavy metals and petroleum hydrocarbons at Atlas Cove Station, Heard Island

Located on the northwest coast of Heard Island, a World Heritage-listed sub-Antarctic territory of Australia, Atlas Cove served as the site of the first permanently occupied Australian National Antarctic Research Expedition (ANARE) station (1947–55). Subsequent to its closure, Atlas Cove Station was abandoned and left largely to the mercy of the natural elements, although it has been visited and occupied on an infrequent basis by ANARE. All activities on the island are now subject to the provisions of the Heard Island Wilderness Reserve Management Plan. During 2000–2001 a major clean-up of the site was undertaken, with most of the remaining structures demolished and material collected for return to Australia and disposal. To assess the extent and intensity of contamination within the station area, soil and water samples were collected and analysed for petroleum hydrocarbons and heavy metals. Assessment of site contamination was made with reference to specific background control limits calculated for Atlas Cove Station, and comparison was also made with Australian and New Zealand guidelines for the protection of aquatic and terrestrial ecosystems. Contamination by heavy metals is evident throughout the station but not at levels of sufficient magnitude to infer a significant potential toxic impact on local ecosystems. Hence remedial action to reduce the concentration and mobility of heavy metals in soil and water is not a high priority, although monitoring of changes at the site through time is recommended. Contamination by petroleum hydrocarbons is at a level that may cause a significant toxic impact on the environment and requires further investigation to assess impacts and possibly to undertake remedial action. Given the large quantity of petroleum-contaminated soil present, remediation processes that can be carried out in situ are likely to be the preferable clean-up options. The benefits of remediation, however, must be balanced against any negative effect this might exert on the plant and animal wildlife that have recolonised this historically important site.