Dr Estelle Lazer
prepared for the 2006 Australian State of the Environment Committee, 2006
A number of the risks to these sites are shared, though certain sites do have specific problems:
- Isolation poses an acknowledged risk to the preservation of these sites (for example, see Godden et al. 2001, p. 121). Structures in any environment will deteriorate without regular maintenance. Access is limited to all Antarctic and Sub-Antarctic sites, but some sites, notably Mawson’s Huts and Heard Island, are particularly vulnerable to neglect as they are only visited as part of dedicated and very expensive expeditions. Any site that is not associated with stations or that is irregularly visited is subject to this risk.
- Tourists can damage sites by inadvertent trampling of artefacts, especially in extreme weather. Increasing numbers of visitors entering buildings, like Mawson’s Hut, put pressure on the structures and may inadvertently damage portable elements.
- Uncontrolled or illegal visits are a potential problem for the more remote sites at Mawson’s Huts and Heard Island. Although permits are required to visit these sites, it is possible that unmonitored landings could occur.
- Weather presents a risk through the extreme conditions, with high wind speeds, ice accumulation and snow loads, which all contribute to the deterioration of elements of cultural heritage sites on the continent. High winds, storm driven seas, rain and associated growth of vegetation pose a threat to Sub-Antarctic sites.
- Climate change . This is a problem for all Antarctic and sub-Antarctic sites. At Mawson’s Huts, for example, increasing summer melt would increase the already high relative humidity inside the Main Hut and may contribute to the destabilisation of the structure. Mould growth would also be increased. Furthermore, the external surfaces of the hut would be more exposed to the harsh environment, as would artefacts scattered across the site (Hayman et al. 1999, pp. 113–118). At Heard Island, glaciers have retreated dramatically in recent decades. In the 1980s, about 80 per cent of the island was covered with glacial ice, though even then there was evidence of significant glacial retreat. Comparison with nineteenth century sealers’ maps indicates that, in just one century, there was a very substantial decrease in the amount of ice-covered areas (Gressitt and Temple 1970, p. 24; Allison and Keage 1986, pp. 255–71). The rate of retreat has increased in the last 20 years (Australian Antarctic Division and Director of Parks 2005, p. 84). The increased size of Stephenson’s Lagoon, for example, poses the risk of erosion and loss of sealers’ sites in the southern portion of the island. Another problem posed by a decrease in ice cover is the exposure of objects previously protected by being encased in ice. Exposed objects could then be threatened by corrosion, corrasion, loss due to exposure to high winds, disturbance by wildlife or visiting humans and accelerated rates of deterioration as a result of the freeze-thaw cycle.
- A specific risk to Heard Island is the dynamic coastline. In 1986, for example, there was a site that comprised 35 wooden oil barrels that had been left by sealers. The number has been diminishing steadily over the last few decades as the barrels have been eroding out of the beach cliff. Less than a quarter of those recorded in the 1980s are still in situ. Some of these were excavated and returned to Australia in 1986, while several more that were under threat were relocated on the island during the summer field season of 2003–04 (Lazer and McGowan 1990, pp. 31, 70, 72; Bruce Hull pers. comm.; Eric Woehler pers. comm.). Erosion and exposure of artefacts is also a problem at Macquarie Island.
- Seismic activity has been identified as a specific threat to structures on Macquarie Island, although most of the Australian National Antarctic Research Expeditions buildings have been built to withstand tremors. Land slippage is also a potential problem (Vincent 2002, p. 109).
- Volcanic activity is a potential threat to sites on Heard Island.
- Wildlife such as elephant seals can exert considerable impact when they move across sites. Overgrowth by plants on Sub-Antarctic islands can lead to obscuring of items, such as the headboards of graves at Heard Island.
- Pressure by continued use of the sites can damage artefacts; however, continued use may secure survival through regular maintenance. Equipment and facilities that are made redundant may not be maintained and may deteriorate.
- A number of the historically significant expeditions left hazardous material behind, including explosives and dangerous chemicals. These now pose a threat to the cultural and natural environment. Some material, such as explosives used by Mawson’s 1911–14 expedition to Cape Denison, has recently been destroyed (Hayman et. al. 1999, p. 27).
- There can be a conflict of interest between the requirements of the Madrid Protocol for site clean-up and the conservation of heritage material.