Land Theme Report
Australia State of the Environment Report 2001 (Theme Report)
Prepared by: Ann Hamblin, Bureau of Rural Sciences, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06748 5
Australia's environmental responsibilities in Antarctica are considerable. Since 1936 Australia has claimed 42% of Antarctica, or 5.5 million km2 of this vast continent, equal to two-thirds of Australia itself, together with the island territories of Macquarie, Heard and McDonald islands.
The Antarctic Treaty (first convened in 1961) covers most activities carried out in Antarctica, and the Madrid Protocol (1991), enshrined in Australian law, bans mining on the continent. Australia's program is devoted to strategic scientific investigations on climate, astronomy, biology of all Antarctic organisms, geosciences, glaciology, oceanography and human impacts. There is strong collaboration between the Treaty nations.
This section was written by John Gibson, Antarctic Division, Environment Australia, Hobart.
Figure 75: Antarctica and Southern Ocean.
Source: ERIN, Environment Australia
A massive ice sheet, in places over 4000 m thick, covers most of the Antarctic continent. This sheet was formed from snow that fell in the interior of the continent and was slowly converted to ice as it was buried by further snowfalls.
The ice flows slowly to the continental margin, where it breaks away as icebergs. The ice sheet has been present for at least 16 million years, and now contains over 80% of the world's freshwater. The surface of the ice sheet is generally a smooth, featureless plain sloping up from the coast to a plateau around 3000 metres above sea level in the continent's interior.
In contrast to the ice sheet, about 0.5% of Antarctica is ice-free, and it is here that most human activities and impacts have occurred. The ice-free areas fall into two major categories: mountainous areas, such as the Transantarctic Mountains, where the terrain and climate limit snow and ice accumulation; and rocky coastal outcrops, where relatively mild conditions, low precipitation, solar heating of the exposed rock, and the presence of large outlet glaciers nearby, combine to maintain the ice-free conditions. The term 'oasis' is often used for these areas, as the exposed rock contrasts dramatically with the ice that covers most of the continent. Most of the scientific bases scattered around the coast of Antarctica are located on small coastal oases.
All the ice-free areas are rocky, being made up of exposed bedrock often covered by a layer of glacially deposited boulders and rocks. In general, there has been very little pedogenesis, with most of the soil present consisting of coarse mineral material produced by physical erosion of the rock. The soil is frozen for much of the year, though in summer the surface warms and interstitial moisture melts. This freeze-thaw cycle helps to break down grains and provides a mixing force to the soil that precludes formation of the structure seen in soils in more temperate areas. The absence of structure results in the soil being unstable, and considerable amounts are blown away during blizzards.
The organic carbon and nutrient content of the soil is generally low, reflecting the paucity of plants and other organisms that can provide organic carbon and can trap nutrients. An exception to this occurs near concentrations of wildlife, including penguin rookeries and seal wallows, where nutrient and organic carbon levels can be very high. The mineral soils, however, are not sterile. Small streams and wetlands formed by melting snow banks are often colonised by communities containing cyanobacteria and algae that are active over short periods during summer.
This productivity in turn supports a community of grazers, including bacteria, nematodes, tardigrades, rotifers and a very limited array of insects. The chemical and biological processes that occur in the soils are generally poorly known, though the productivity (in terms of grams of organic material per square metre) is on average very low.
The Antarctic ice sheet leaves only rocky outcrops free of ice.
Source: Bureau of Resource Sciences
The three permanently occupied Australian National Antarctic Research Expeditions (ANARE) scientific stations-Casey, Davis and Mawson-are all located in coastal oases. Russia, China and Poland also maintain permanently or sporadically occupied bases within the Australian Antarctic Territory. The presence of the stations and the human activity associated with them provide some of the major environmental pressures on the landscape. Impact stems to a large extent from the stations' physical presence, with a considerable area taken up by the direct footprint of the buildings and services, such as water and sewerage pipes. Equipment stores, roads and communications aerials affect a larger area. It is now part of the Antarctic Treaty system that, if a station is permanently closed down, all buildings and other indications of human habitation must be removed. However, Wilkes, a major base originally built in the 1950s but abandoned in the early 1960s, remains largely intact. The buildings and stores, including rusting fuel drums and explosives, are slowly being buried by snow and ice, and are sources for pollution of the local environment. The encroaching ice has made it particularly difficult to rehabilitate the site.
The Australian stations are currently run on sound environmental guidelines, but this has not always been the case. In the 1950s and 1960s, large waste dumps developed near the station and other rubbish was disposed of directly into the marine environment.
The legacy of this activity is only now becoming clear, and major research projects are being undertaken at Casey to investigate and ameliorate the effects of this dumping both on land and in the sea. For example, methods are being developed to intercept and contain groundwater flows containing high levels of toxic heavy metals before they are discharged to the sea. Another area of particular concern is the Larsemann Hills, where Australia, China and Russia have a presence. The intensity of the habitation and differing rationales for the presence of the bases has resulted in extensive pressure on the environment over a relatively large area. This pressure is due to the development, in some cases, of unnecessary or poorly designed roads, release of rubbish, and changes in the hydrology and nutrient loading of lakes. Improved environmental guidelines are now in place in this area, and attempts are being made to develop an international management scheme.
There has been little direct impact of mankind on the ice sheet, as there has still been relatively little exploration of the interior. Permanent scientific bases are limited to the South Pole and Vostok, where Russia has maintained a base since 1957. There have, however, been indirect impacts, largely from long distance transport of pollutants from the north. For example, lead concentrations increased in Antarctic snowfall, and therefore continental ice, with the introduction of lead as a fuel additive, but have now begun to decrease with the wider usage of unleaded fuel.
Pristine areas need to be protected and maintained for future generations.
Source: Bureau of Resource Sciences
An increasing pressure on the Antarctic environment comes from tourism. More and more people are visiting the continent by ship, with many voyages aimed at reaching rarely visited areas or sites of particular historical or scientific importance. Although these tours are generally run under strict environmental guidelines, some degradation of the environment will occur. The nature of the Antarctic environment is that damage may be long lasting, with vehicle tracks or footprints in muddy ground being visible for many years. Very few, if any, of the ice-free areas of the Australian Antarctic Territory remain to be visited, either by scientists or tourists.
The responses to these human-derived environmental pressures have largely involved the sequential development of better environmental practices, many of which are now enshrined in law. For example, the Madrid Protocol to the Antarctic Treaty bans all mining activity south of 60S and provides strict guidelines on waste management and disposal.
Environmental impact assessments must now be prepared for all activities that might affect the environment, such as building and road construction, as well as scientific projects. Most non-human waste is now returned from Australian bases, and sewerage systems have been installed to preclude negative impacts on the inshore marine environment. Reduction in energy usage is an aim for the Australian bases, and active research is being undertaken into the use of renewable energy sources. Use of vehicles outside the stations is limited to on-ice use only, and some regions have been protected as Sites of Special Scientific Importance or Specially Protected areas to protect particular environmental attributes.
Education of all people going to Antarctica, whether they are scientists, tourists or support staff, is very important. If visitors have an appreciation of the environment they are visiting, they are more likely to comply with rules and modify their own actions to protect the fragile environment they have travelled a long distance to study or see.