Australian Antarctic Territory, Territory of Heard Island and McDonald Islands, and observations on Macquarie Island Tasmania
Australian National Committee on Antarctic Research
prepared for the 2006 Australian State of the Environment Committee, 2006
There are nine permanent stations in Australia’s Antarctic Territory, not including the United States’ Amundsen-Scott base at the south geographic pole. Six are coastal, and include the three Australian stations: Mawson, Davis and Casey. When considered against the almost six million square kilometres of Australia’s Antarctic Territory (42 per cent of Antarctica), this is an extremely low density, and far lower than either the Antarctic Peninsula or West Antarctica, which together share the other fifty-odd permanent stations.
Some environmental disturbance is an inevitable consequence of human activities in Antarctica. There are five main human activities with a potential for adverse impact on the Antarctic environment: the conduct of scientific research, logistic operations, tourism, construction of buildings and infrastructure, and commercial harvesting of living resources. The major concerns associated with these activities are the transport, transfer and storage of large quantities of diesel fuel, introduction of non-native species and disease, generation of waste and pollution , disturbance of the physical environment, and wildlife disturbance by visitors and vehicles .
Some proxy indicators of environmental pressure, such as fuel use, visitor numbers and wastewater production, indicate the potential environmental impacts of human activities and provide a benchmark against which to frame management measures. Data on these indicators are difficult to obtain for the non-Australian stations, and so the overall picture of station pressures on Australia’s Antarctic Territory environment cannot be determined accurately.
Australian research is being directed towards reducing the impact of human pressures by improving renewable energy sources, understanding the environmental effects of terrestrial and marine contaminants, and establishing the minimum-approach distances to wildlife. The Australian Government Antarctic Division has implemented procedures and guidelines to prevent and detect the introduction of non-native species to Antarctica and the sub-Antarctic, and is working with its Antarctic Treaty partners to refine and implement them throughout all Antarctic operations.
Managing tourism and non-government visits is far from straightforward. The multi-national nature of Antarctic tourism, the complex political and juridical situation in Antarctica and the sparseness of Antarctic infrastructure create a layer of management challenges on top of the more obvious environmental protection and safety aspects.
Tourist visits to Australian sub-Antarctic islands and the Australian Antarctic Territory account for a small proportion (less than one per cent) of the world total of Antarctic-bound shipborne tourists. The data suggest no increase in tourist visits to Australian sites, in contrast with a clear trend of increasing numbers of visitors to Antarctica as a whole: the total number continues to grow at a rate of over 10 per cent per annum, to over 30 000 shipborne tourists in 2004–05, not counting guides and crew (IAATO 2005). Since 2002–03, 100 tourists on four vessels have visited Commonwealth Bay, the site of Mawson’s huts.
Tourist visits are concentrated on the Antarctic Peninsula and the Ross Sea region (ASOC, and UNEP 2005), which is not part of Australia’s Antarctic Territory. Most tourists visiting Antarctica do not stay ashore overnight, and most Antarctic Treaty parties allow no more than incidental use of their facilities by tourists.
Increased tourism in Antarctica gives rise to various concerns, including the potential for direct and cumulative environmental impacts resulting from wildlife disturbance, pollution from increased shipping, and the possible introduction of exotic pests or diseases.
Visits to Heard Island are infrequent, with only 202 tourists on six vessels between 1995 and 2004. There were no authorised visits in six of the last ten years, and the last visit was in 2002–03, involving one ship visiting for two days accompanied by an Australian Government Antarctic Division guide. One private visit to Heard Island is mooted for the 2006–07 summer. The low level of visitation is probably best explained by the substantial travel time and costs arising from the island’s remoteness, rather than a lack of features of interest to tourists.
In the 18 years since 1987, 5180 tourists on 75 vessels have visited Macquarie Island. Tourist visits have been recorded at Macquarie Island every year since 1992–93.
Tourists have visited Macquarie Island at a relatively constant rate over the past ten years. To date the seasonal total has remained below the limit set by the Tasmanian management plan, which is currently 750 tourists per year. 2005–06 is expected to be the first season in which approvals exceed the limit. However, this is viewed as a one-off, and the Parks and Wildlife Service has no plans to change the overall limit or to modify site limits. In addition to its own attractions, Macquarie Island is a half-way point for voyages between Hobart and East Antarctica, most of which also use the ports of Lyttelton and Bluff in New Zealand.
The Australian Antarctic program makes between five and seven voyages each summer: between 1987–88 and 2004–05, there were 147 voyages to the Antarctic, recording nearly 374 000 person-ship-days. RSV Aurora Australis is the main means of transporting Australian Antarctic personnel and has a maximum carrying capacity of 116 expeditioners.
Since 1987–88 Davis has had the largest aggregate population, with 251 294 person-days, followed by Casey with 221 200, Mawson with 202 574 and Macquarie Island with 162 362. Since 1994, there has been a decrease in the number of people travelling to Australia’s Antarctic Territory and a decrease in average station population, and there is strong seasonal variation, with the summer station population two to four times that of the winter. The peak in continental station population in the 1980s and early 1990s was due to an increase in the number of trades personnel completing a major rebuilding programme. Although some replacement of buildings as a result of ageing and wear and tear will take place, it is not envisaged that the current stations will be expanded. The heritage values and conservation needs of structures from earlier years are being assessed under the Environment Protection and Biodiversity Conservation Act 1999 and the heritage strategy of the Department of the Environment and Heritage (DEH 2005).
Davis is the base of investigations into the biology, geology and glaciology of the Prince Charles Mountains – Lambert Glacier – Amery Ice Shelf region, and the home of a major atmospheric physics programme using laser technology, radar and other equipment to investigate the stratosphere and mesosphere.
It is expected that the introduction of intercontinental air transport in 2007–08 will result in short-term increases in the population of Casey, which is the Antarctic terminus.
In the sub-Antarctic, the Commonwealth’s management and research focus is shifting from Macquarie Island to Heard Island. The Australian Government Antarctic Division has reduced its ship visitation to Macquarie Island to one visit per year, and tourist vessels have been used to fill the gap.
There is expected to be a small increase in person-days on continental stations from 2007 as a result of the commencement of direct flights from Hobart to Antarctica: while more expeditioners will visit, the duration of their stay will be shorter.
Wastewater is a source of local environmental pollution. Environmentalists, ecologists, wastewater specialists and others have been critical of the disposal of untreated sewage into the sea in Antarctica (Meyer-Rochow 1992). While the biological impacts are not well understood (Meyer-Rochow 1992), studies have noted:
- the potential for sewage microorganisms to remain viable in Antarctica’s environment for prolonged periods (for example Meyer et al 1962, Hughes and Blenkharn 2003)
- that faeces in Antarctica’s terrestrial environment may contain viable microorganisms some 30–40 years after deposition (Hughes and Nobbs 2004)
- that, along with contaminated food, the release of untreated sewage is the most likely risk factor for the introduction of pathogenic bacteria and viruses to Antarctica (Bonnedahl et al 2005).
At Casey and Mawson, sewage waste and grey water are processed through rotating biological contactors (RBCs), using a combination of mechanical and microbial action to treat sewage waste. Effluent is discharged into the sea adjacent to the stations, and sludge is removed to Australia for disposal.
When the RBCs are bypassed due to equipment failure, for annual maintenance or because the station population exceeds system capacity, waste is macerated by being passed through a pump, but is otherwise untreated before being discharged into the sea.
There is a strong correlation between the quality of the effluent and the annual summer population increase. This is evidenced by the spikes in the Casey and Davis graphs, where the station population tripled or quadrupled over the summer period. The relatively flat response on the Mawson graph further illustrates the correlation, as the station population only doubles over the summer period. The collection of effluent data has been intermittent during the summer periods at Casey and Davis because of the necessity to by-pass the RBCs when the stations’ population exceeds the RBCs’ capacity. The Davis RBC failed irreparably in 2004, and options are under development to improve sewage treatment at all Australian stations.
A co-generation system is used to provide both electrical and thermal energy to the Australian stations. Waste heat created by diesel generators heats water that is then pumped around the station to heat each building. This is usually only sufficient to heat the station for three months during summer, and fuel-fired boilers are used to boost the system during winter.
Annual fuel consumption for the production of thermal and electrical energy at the stations has been decreasing over the past 10 years as a result of an energy management program. The significant decrease in fuel consumption at Mawson is due to the introduction of large-scale wind turbines with sophisticated control systems, and a computerised building management and control system.
Each station has a high-temperature incinerator that is used to incinerate kitchen waste, some packaging waste, and other waste such as field waste that is not suitable for return to Australia. Incinerator waste is stockpiled until there is sufficient waste to warrant a burn. Over winter this can be weekly; over summer it is often daily. The quantity of fuel used provides some indication of the quantity of waste produced, which depends on the stations’ population and the nature of the programs conducted.
In 2004–05 the Australian Antarctic stations incinerated a total of 56 190 kg of waste, which is 14 per cent of all waste produced by Australian Antarctic operations in that period. Most waste from Antarctic stations is returned to Australia where it is recycled, reused, or treated and disposed of to landfill. The total fuel used in incinerators has dropped by 10 per cent over the past five years.
The annual peaks and troughs in waste figures correspond to the stations’ populations. The spike in the Mawson data in 2002–03 is due to a large field-based program.
The incinerators are quite old (over 20 years) and are rapidly approaching the end of their serviceable lives. Alternative methods of organic waste disposal and more efficient incinerators are being investigated.
The energy management strategies put in place by Australia’s Antarctic Division over the past decade have been successful. Further significant reductions in fuel usage, however, will be difficult without a large investment in alternative energy systems.
Australia’s stations have a reticulated water system which provides for all potable, cleaning, heating, domestic and industrial uses from one station source. Water consumption is regulated according to the abundance of supply, and also varies according to the nature of the activities being undertaken (such as construction and concrete mixing), the station’s population, and, for the continental stations, the extent of the summer thaw.
Because of the high rainfall, catchment configuration and small station population, water use at Macquarie Island is not considered to have any negative environmental impacts.
Although freshwater in the Vestfold Hills is abundant in the summer months, Davis station is several kilometres distant from the nearest source. Potable water is produced by reverse-osmosis of saline water from a nearby tarn and stored in tanks with a total capacity of 1 430 000 litres, which is considered adequate for a maximum population of around 65 people. Brine from the reverse-osmosis plant is discharged to the sea. Increasing summer populations are stretching the station’s water-making capacity, leading to regular summer water restrictions and the investigation of alternative water sources.
At Casey and Mawson, meltwater from the summer thaw is captured and stored in 270 000-litre tanks, and drawn from melt-lakes during the winter. Predicted future peaks in the Casey population due to the air transport system are expected to strain its water supply, and storage capacity may have to be increased.
The environmental aspects of water supply at the continental stations are the use of fuel to generate electricity to maintain the water in a liquid state, and at Davis to run the reverse-osmosis plant. These effects are not considered to be significant.