Humans maintain a presence in Antarctica and have a direct influence on some areas, particularly ice-free areas, through various activities. Continent-wide, there are about 1,100 people in winter and 4,400 people in summer on the various research stations (World Population Review 2021).
Before the COVID-19 pandemic, more ships and aircraft were visiting Antarctica than ever before, making pollution with hydrocarbons (fuel, oil) through leakage and spills a real risk to the environment, particularly for benthic communities (Polmear et al. 2015). Disturbance to wildlife can be an issue; this includes visits to breeding areas, and noise pollution by aircraft, ships and machinery. Even simple activities such as walking can affect habitat, particularly soils. Trampling of soils can result in their compaction, which alters the surface structure, nutrient cycles, and soil and plant communities (Tejedo et al. 2014).
Antarctic stations
In 2017, 29 nations collectively occupied 40 Antarctic year-round stations, and another 36 facilities operated only during summer (October to March) (COMNAP 2017). Some 27 stations had been constructed before the adoption of the Environmental Protocol to the Antarctic Treaty (Brooks et al. 2019). Several old, abandoned stations continue to deteriorate. In addition, field huts and refuges, weather stations, runways, historical huts and tourist camps increase the human footprint in Antarctica (Brooks et al. 2019). On the continent, construction of stations is continuing; for example, in 2018, China constructed a temporary station at Inexpressible Island, Ross Sea, while finalising a Comprehensive Environmental Evaluation for the construction of a permanent base there.
Sixty stations have been built on gravel or soil sites and 17 on rock. Gravel or soil sites occupy areas that are often breeding habitat of wildlife or where terrestrial vegetation is abundant. Permanent alteration of the substratum can lead to changes in the geomorphology and water cycle, and loss of wilderness and aesthetic values (Brooks et al. 2019).
Australian Antarctic stations
Australia maintains 3 year-round continental research stations (Casey, Davis and Mawson), and 1 at subantarctic Macquarie Island. Remote field bases operate during the summer season, including Wilkins Aerodrome, 70 km inland from Casey Station. The station populations range from 40 to 100 expeditioners over summer, and 15 to 20 over winter. Each season, about 500 expeditioners travel south with the Australian Antarctic Program.
The Australian Antarctic Division (AAD) maintains an Environmental Management System (EMS) consistent with AS/NZS ISO 14001. The EMS is a systematic means of managing the AAD’s activities, using a set of operational indicators to monitor and assess human impact on the environment associated with the Australian Antarctic Program during the planning, operational and continual improvement stages.
The operation of Antarctic stations requires a significant amount of energy. The total fuel consumption of Antarctic operations was relatively steady over 2015–16 to 2019–20, and ranged from 6.4 to 7.1 megalitres (ML). Shipping and aircraft operations use 40–45% and 21–24% of the total fuel, respectively (see Shipping and air operations). The remainder is used in station operations, mainly to generate electricity (Table 5).
Electricity is needed to heat buildings and water tanks, to provide light, especially through the long Antarctic winter, to operate workshops, and so on. From 2015–16 to 2019–20, overall electricity use per person increased by 11.4%, from 0.166 terajoules (TJ) to 0.185 TJ (46,100 kilowatt hours (kWh) to 51,390 kWh).
The total electricity generated by diesel increased by 6.5% from 18.5 TJ in 2015–16 to 21.5 TJ in 2019–20. At Mawson Station, the wind turbine has suffered some technical issues in recent years. In 2019–20, it produced only 1.7 TJ (420,200 kWh), compared with 5.9 TJ (1.64 × 106 kWh) in 2016–17, a decrease of 68% (DAWE 2020a).
Water
Free-flowing water for human use is greatly limited in Antarctica. On stations, water is required for domestic uses (kitchen, showers, laundries), in workshops and in other operational buildings. Water is stored in large tanks. Special tanks designated for firefighting in case of an emergency comprise two-thirds of the water stores on stations. These tanks are heated so that the water can be used all the time. Water is produced by melting snow and ice in special facilities, or, at times during summer, from seawater using reverse osmosis.
Water-saving behaviours are encouraged among expeditioners. However, the consumption of water (and energy) does not always reflect the size of the station population but may reflect an increase in, or change of, activities. For example, overall water consumption increased during 2018–19 compared with previous years, as did energy consumption, although there were fewer expeditioners than in previous years (DEE 2019).
Overall, water consumption increased from 6.27 ML in 2015–16 to 6.83 ML in 2018–19. As a result of the COVID-19 pandemic in 2019–20 and reduced operational activities, water consumption dropped slightly to 6.15 ML (Table 5).
Waste management
Each year, waste and materials no longer required on station are returned to Australia for recycling, re-use or disposal. Waste typically includes general landfill and commingled recycling, such as paper, glass, aluminium and plastic (polyethylene terephthalate – PET, and high-density polyethylene – HDPE), sewage sludge, paint, oil, steel, copper, brass, building materials and laboratory chemicals.
Quantities of waste returned to Australia vary annually and with capacity of ships to transport these materials. From 2015–16 to 2019–20, the amounts of liquid taken from Antarctica ranged from 10 to 54 t. Over the same period, the quantities of materials sent to landfill ranged from 90 to 191 t, but 73% more recyclable material was returned to Australia (DAWE 2020b, DAWE 2020a).
Wastewater derives from various parts of a station, and includes greywater from the kitchen, showers, workshops and laboratories. This water contains a mix of contaminants, including chemicals, detergents, medications and cosmetics. Generally, wastewater treatments are used to reduce the level of nutrients and microorganisms (Corbett et al. 2014). The treated water is released into the nearshore environment, and solids are returned to Australia.
Shipping and air operations
Each year, various ships and aircraft transport people and goods to and from Australia’s 4 permanently occupied research stations of Casey, Davis, Mawson and Macquarie Island. During recent years, the winter populations at the Australian stations have remained relatively stable; there have typically been 16–22 people on each of the continental stations, and 13–15 on Macquarie Island. For many years, Davis Station had the largest summer population, with up to 100 personnel. However, with efforts to modernise station facilities, this number is likely to increase over the coming years. Casey Station has a much larger number of expeditioners coming and going throughout the summer season because of the improved access to Antarctica by air transport. Prevailing weather conditions do not allow use of the runway during winter.
The AAD undertakes voyages for a range of purposes, primarily resupply of the stations, and deployment and retrieval of personnel, as well as marine science research. The new icebreaker RSV Nuyina (see case study: Cultural connections of RSV Nuyina) arrived in Hobart in October 2021, and will be the primary vessel used for logistics and research conducted under the Australian Antarctic Program. Occasionally, the AAD charters other vessels to augment activities, such as waste removal, Southern Ocean and marine science research activities, and transport of personnel to and from Macquarie Island.
The AAD also uses a variety of aircraft to transport passengers and cargo, including the Royal Australian Air Force’s C-17 Globemaster III, which has delivered heavy cargo to Wilkins Aerodrome in support of the Australian Antarctic Program. Use of this type of heavy-lift aircraft has improved the AAD’s logistical and scientific capabilities.
Fuel consumption by vessels decreased by 34.7% from 3.34 ML in 2015–16 to 2.48 ML in 2019–20; fuel use by aircraft remained relatively steady, averaging 1.49 ML in this period (DAWE 2020a).
Over the past 5 years, total greenhouse gas emissions (tonnes of CO2 equivalent) decreased by 10% from 19,894 t in 2015–16 to 17,917 t in 2019–20 (Table 6), partly due to variations in operational demands. Variations in the use of fuel for ships is related to the size and number of vessels used and whether or not marine science voyages are undertaken. For example, in 2017–18, the RSV Aurora Australis undertook 4 voyages, and no additional vessel was chartered as in the previous 2 seasons (Australian Antarctic Program 2021). Sea ice conditions also influence fuel use; when the sea ice extent is reduced, less fuel is required to break ice.
Many aspects of the station environment are good. The treatment of waste is good, and remediation of contaminated sites is improving contamination levels. However, the overall footprint is increasing, and fuel use at stations and by vehicles is high and increasing.
The human footprint is increasing through modernisation of stations and logistical requirements.
The amount of waste returned to Australia depends on the cargo limits of ships and varies from year to year.
Return of recyclable waste increased by 73% to 111 t over the past 5 years.
The amount of water required varies with the number of people and operational activities.
Quantity of fuel used is high but relatively steady at all stations.
Fuel use is highly variable at all stations. Increase in fuel use at Casey and Davis stations due to increased activities.
Use of electricity is linked to fuel use. The loss of wind turbines increased electricity production by diesel.
Vessels transport goods and people, and undertake marine science voyages. Annual fuel consumption varies, and depends on the number of voyages and sea ice conditions.
This is variable from year to year and is dependent on quantities of goods and numbers of people transported by aircraft.
Remediation work is continuing and progressing.
Management plans are in place for all protected areas.