Logo of State of the Environment 2011; Photo by Andrew Griffiths, Lensaloft

State of the Environment 2011 (SoE 2011)

State of the Environment 2011 Committee. Australia state of the environment 2011.
Independent report to the Australian Government Minister for Sustainability, Environment, Water, Population and Communities.
Canberra: DSEWPaC, 2011.

7 Antarctic environment

3.3 Pressures on Antarctic historic heritage

The buildings and structures that make up Australia's historic heritage were built up to 100 years ago. At the time of their construction, they were built to last only a few years (e.g. Mawson's Huts at Commonwealth Bay). It was never anticipated that they would still be standing a century later and considered a valuable part of Australia's Antarctic heritage.

The building materials are vulnerable to deterioration and the greatest threat to the integrity of the buildings and structures lies in the natural elements. Wind, weather, frost, ice and melt water all contribute to the deterioration of buildings. Corrosion, fungal growth, wind and snow loads, exposure to ultraviolet radiation, the freeze-thaw cycle and high relative humidity inside the main hut affect the conservation of structures and artefacts.182 An artefacts conservation program was instigated in 2008.214-216

The illegal removal of artefacts is also a concern. All visitors require permits if they intend to visit the island; however, the region's remoteness-which has protected its natural values-also makes it extremely difficult to control unauthorised access. For example, fishers on illegal fishing vessels operating in the area may visit and remove artefacts.

On the subantarctic islands, the maritime climate promotes corrosion of metal artefacts. Wooden items are abraded by windborne sand and salt particles. Disturbance by wildlife, land erosion and slippage is also a potential problem,186,217-218 as is erosion and exposure of artefacts. Cultural heritage on the islands may also be damaged by volcanic and seismic activities. Seismic activity has been identified as a specific threat to structures on Macquarie Island, although most of the research expedition buildings have been built to withstand tremors.182

Heard Island is a long way from Australia and caring for the components of historic heritage on the island is an enormous challenge. The cultural heritage of Heard Island is conserved through a process of managed decay. This is a pragmatic management option, which acknowledges the practical impossibility of conserving all elements of the cultural environment in a remote area where access is extremely limited.182,217 Permitted visits are highly infrequent and tend to be restricted to the short summer. The management plan states that heritage values, such as buildings, are and have been in a greatly deteriorated state for a long time and are permitted to disintegrate under the influences of weather and climate. There are several sealers' graves in the south-eastern part of the island, not far from a large king penguin colony. The vegetation cover is dense and continues to engulf and cover the old graves.

A specific risk to Heard Island is the changing coastline. For example, wooden oil barrels that were left by sealers at Oil Barrel Point have disappeared steadily over the past few decades as the barrels have eroded out of the beach cliff.219 Fewer than a quarter of those recorded in the 1980s are still in place.

Assessment summary 7.13-pressures affecting Antarctic historic heritage
Component Summary Assessment grade Confidence in grade Confidence in trend
Very high impact High impact Low impact Very low impact
Melt water

Fine snow particles penetrate the buildings and fill the buildings; causes structural damage and damage to artefacts

Recent trends: Deteriorating Confidence: Adequate high-quality evidence and high consensus Confidence: Adequate high-quality evidence and high consensus
Wind

Can limit conservation work and destroy weakened structures

Recent trends: Deteriorating Confidence: Adequate high-quality evidence and high consensus Confidence: Adequate high-quality evidence and high consensus
Climate change

Increased wind strength and frequency of storms puts pressure on huts

Recent trends: Deteriorating Confidence: Adequate high-quality evidence and high consensus Confidence: Adequate high-quality evidence and high consensus
Coastal erosion

Dynamic coastline at Heard Island changes and threatens some artefacts

Recent trends: Deteriorating Confidence: Adequate high-quality evidence and high consensus Confidence: Adequate high-quality evidence and high consensus
Fauna and flora

Wildlife such as elephant seals can exert considerable impact when they move across sites

Overgrowth by plants on subantarctic islands can lead to obscuring of items, such as the headstones of graves at Heard Island
Recent trends: Deteriorating Confidence: Adequate high-quality evidence and high consensus Confidence: Adequate high-quality evidence and high consensus
Unauthorised collections

Could occur at Heard Island; unauthorised visits possibly occur

Confidence: Evidence and consensus too low to make an assessment Confidence: Evidence and consensus too low to make an assessment
Recent trends  Improving  Stable Confidence  Adequate high-quality evidence and high level of consensus
 Deteriorating  Unclear  Limited evidence or limited consensus
 Evidence and consensus too low to make an assessment
Grades  Very low impact: Component is hardly impacted by factor and requires no further conservation efforts
 Low impact: Factor impacts on part of the component and may require further conservation efforts
 High impact: Factor impacts component moderately and requires further conservation efforts
 Very high impact: Factor impacts component significantly and limits further conservation efforts
Antarctic chapter title page