Risk Assessment and Environmental Guidelines
We are working to improve our protection of the Antarctic environment from contaminants. To do this in a scientifically robust way we are using a diverse range of methods to develop Environmental Quality Guidelines (EQGs) and remediation targets for a range of common contaminants (such as fuels and metals including copper, cadmium, zinc and lead), for marine and terrestrial environments in both Antarctic and subantarctic regions.
EQGs can be used in environmental risk assessments to predict whether there are likely to be impacts on the environment and biota caused by anthropogenic (human) activities. EQGs provide science-based goals for ecosystem quality and remediation targets to protect the environment. Once developed, these tools will be implemented onsite to inform Australia's remediation (clean-up) activities, including at fuel spill sites at Casey and Macquarie Island. The tools will allow us to determine when these sites are clean enough and no longer pose significant environmental risk, so we can enable site sign-off and approve soil reuse.
While guideline frameworks are well established in Australia and in temperate regions worldwide, no such guidelines for soils or for marine waters exist for the Antarctic and subantarctic regions. Our development of environmental management tools and guidelines that are specific to these regions will enable us to responsibly manage contaminants found at our impacted sites, such as adjacent to rubbish tips, in fuel spill sites, at sewage discharge sites, and around Antarctic stations.
To develop these tools, we are using a suite of ecotoxicology methods to assess how local species respond to contaminants. Toxicity tests are conducted both at our research stations during summer field seasons, and back at the Australian Antarctic Division headquarters in Kingston, year round.
Antarctic and subantarctic biota used for tests are cultured and kept healthy prior to testing in our portable purpose-built field aquarium in Antarctica, and in our cold water marine research facilities at Kingston. Tests include single species, microbial community genetic traits, and soil health indicators and processes, as well as more novel multispecies and community-based approaches to determine responses of biota to contaminants. These latter measures are more complex to assess but can provide more environmentally realistic results.
Results from toxicity tests indicate the levels of specific contaminants likely to impact local Antarctic biota. A major challenge for this work is that the number of species and communities available to work with are very limited, due to low biodiversity supported in our polar regions, particularly in terrestrial soil habitats. The data combined from these various approaches will be used to inform our EQGs and environmental risk assessments.
Another challenge for this work is that standard toxicity test methods have not previously been established for native polar biota. To determine if a species is sensitive to a given contaminant, we first need to establish standard test protocols for each species we work with. We are making good headway with this, and we now have developed protocols for a number of Antarctic species, including:
- three terrestrial mosses (Schistidium antarctici, Bryum pseudotriquetrum and Ceratodon purpureus)
- a terrestrial algae (Prasiola crispa)
- marine microalgae (Phaeocystis antarctica and Cryothecomonas armigera) and
- a range of marine invertebrates (including copepod Oncaea curvata, amphipods Orchomenella pinguides and Paramoera walkeri, microgastropod Skenella paludinoides, ostracod Bradleya antarctica, polychaete Spirorbis nordenskjoldi, and sea urchin Sterechinus neumayeri).
For the subantarctic, tests have been developed for:
- an earthworm (Microscolex macquariensis)
- plants (including Poa foliosa, Colobanthus muscoides and Luzula crinita) and
- a range of marine invertebrates (including isopod Exosphaeroma gigas, bivalve Gaimardia trapesina, copepod Tigriopus angulatus, flatworm Obrimoposthia ohlini, and sea cucumber Pseudopsolus macquariensis).
The sensitivity estimates we have determined for these taxa form the scientific basis for deriving our site specific guidelines and targets. These guidelines are used to inform and direct clean-up and remediation activities at contaminated sites, and operational upgrades to existing infrastructure and practises dealing with waste discharge from stations.
Australia is a leader within the Antarctic Treaty community in this field. This work will be adopted into the Antarctic Clean-up manual (2014), which will be promoted for use through the Committee for Environmental Protection (CEP) to improve our protection of the Antarctic continent.