Heard and McDonald Islands (577)
inscribed as a World Heritage Site in the year
1997, the Heard and McDonald Islands are volcanic
islands located in the Southern Ocean, in western
Australia. These islands are approximately 1700 km from
Antarctica and cover a total area of 658,903 hectares.
Heard Island recorded the last volcanic activity in the
1980s and the McDonald Islands in the 1990s. Heard
Island is dominated by snow and glaciers. Both these
islands are dominated by large volcanic mountains.
The islands are low in species diversity. Due to their
geographical remoteness, the number of visitors here is
very low, and hence the islands do not face any threats
caused by anthropogenic activities and non-native alien
species. Climate change serves as the major threat to
the site. It is responsible for the retreat of the glaciers,
increasing the chances for the invasive species to thrive.
The current management practices have been efficient
in dealing with the threats in the region, although it is
difficult to carry out regular onsite monitoring due to
the remoteness of the site. The islands are administered
under the Heard and McDonald Islands Act of 1953
and the Environment Protection and Management
Ordinance of 1987 by the Antarctic Division of the
National Department of Tourism, Arts and the
Environment. According to these acts, strict biosecurity
norms are to be followed while visiting the site.
The Heard and McDonald Islands are located
in the Southern Ocean, 4100 km southwest of Perth,
western Australia, and approximately 1700 km from
Antarctica. These islands are home to Australia’s only
active volcanoes. The site covers a total area of 658,903
hectares of which about 37,000 hectares is terrestrial.
The McDonald Islands are located 43 km west of Heard
Island. The last volcanic activity occurred during the mid1980s in Heard Island and in the 1990s in the McDonald
Islands. The size of the McDonald Islands doubled with
an increase in elevation by about 100 m, due to the
volcanic activity. These volcanic islands ‘open a window
into the earth’, and provide an opportunity to observe
ongoing geomorphic processes and glacial dynamics
(whc.unesco.org).
The islands are a typical example of a sub-Antarctic
island group with low species diversity but with huge
populations of certain species (Dasett 1990). These
islands has pristine ecosystems in the world, with
complete absence of alien animal and vegetal species
and with minimal impact from human activities. The
site provides a crucial habitat for large populations of marine birds and mammals.
The ongoing evolutionary process is demonstrated by the endemic species in the
region. According to Woehler et al. (1982), the seabird
and seal communities on the islands account for a total
of 27,893 tons of biomass, of which 70% is attributable to
15 breeding species of seabirds. The site is an important
habitat for a number of resident breeding and transitory
populations of seabirds, seals and the distributionrestricted black-faced sheathbill (IUCN World Heritage
Outlook Report 2020).
The volcanic activity on the McDonald Islands in the
1990s resulted in the complete loss of vegetation.
The main vegetation communities on Heard Island are
tussock grassland, herbfield and feldmark, with smaller
areas of meadow, pool complex and cushion carpet. The
overall biodiversity of Heard Island is contributed mostly
by non-vascular plants: there are 62 recorded species
of bryophytes and 71 recorded species of lichen. It is a
significant site for the study of plant colonization due
to the isolation of plant communities combined with
the increasing growth of habitat resulting from glacial
retreat (Ryan and Scott 2004).
Criterion (viii)
The islands contain outstanding examples of
significant on-going geological processes occurring in an
essentially undisturbed environment, particularly physical
processes which provide an understanding of the role
of crustal plates in the formation of ocean basins and
continents, and of atmospheric and oceanic warming.
The islands are distinctive among oceanic islands in being
founded upon a major submarine plateau which in this
case deflects Antarctic circumpolar waters northwards,
with striking consequences for geomorphological
processes. They also offer an active example of plume
volcanism, providing direct geological evidence of the
action of the longest operational plume system known
in the world. This includes information about plume
interaction with overlying crustal plates, as well as insights
into mantle plume composition due to the widest range of
isotopic compositions of strontium, neodymium, lead and
helium known from any oceanic island volcano system. Big
Ben on Heard Island is the only known continuously active
volcano on a sub-Antarctic island, whereas the volcano
on MacDonald Island recently became active again after a
75,000 year period of dormancy, increasing significantly
in size since inscription. Heard Island’s relatively shallow
and fast-flowing glaciers respond quickly to climate
change, faster than any glaciers elsewhere, making them
particularly important in monitoring climate change.
They have fluctuated dramatically in recent decades and
have retreated significantly.
Criterion (ix)
Heard Island and McDonald Islands are outstanding examples representing significant on-going ecological, biological, and evolutionary processes. As the only subAntarctic islands virtually free of introduced species and with negligible modification by humans, they are a classic example of a sub-Antarctic island group with large populations of marine birds and mammals numbering in the millions, but low species diversity. These intact ecosystems provide opportunities for ecological research investigating population dynamics and interactions of plant and animal species, as well as monitoring the health and stability of the larger southern oceans ecosystem. Areas of newly deglaciated land as well as areas isolated from each other by glaciers provide unparalleled opportunities for the study of the dispersal and establishment of plants and animals. The islands also furnish crucial, alien-free habitat for large populations of marine birds and mammals, including major breeding populations of seals, petrels, albatrosses and penguins. Endemic species demonstrating ongoing evolutionary processes include the Heard Island cormorant, the endemic subspecies of the Heard Island sheathbill, and a number of endemic invertebrates (some endemic to Heard and McDonald Islands, and some endemic to the Heard and McDonald Islands-Kerguelen region).
Status
The property is managed as a strict nature reserve
by the Australian Antarctic Division through Australian
Government’s Heard Island and McDonald Islands
Marine Reserve Management Plan primarily for scientific
research and environmental monitoring (whc.unesco.
org). Strict measures have been incorporated by the
management authorities to minimize the introduction
of non-native species in order to conserve the native
species of plants and animals and also prevent the
adverse impacts of waste and pollution (McIvor 2007).
According to the IUCN World Heritage Outlook Report
(2020), climate change is the biggest threat in the area
resulting in the colonization by the flora and fauna (IUCN
World Heritage Outlook Report 2020; Bergstrom et al.
2015) and also in ocean acidification (Kawaguchi et al.
2013). It is responsible for the accelerating retreat of
glaciers, causing the alien grass species Poa annua to
displace the native vegetation in deglaciated regions
on Heard Island. Visitors serve as the major factor
responsible for bringing the alien species to the islands
(IUCN Consultation 2020). Poa annua is expanding at an
alarming rate leading to competition among the native
vegetation, thus causing a disturbance in the ecosystem
(Meyere et al. 2000). If visits to this site occur without
proper biosecurity measures, it might have serious
environmental consequences (IUCN Consultation 2020).
Threats like accumulation of solid waste in the marine
area cause deterioration in the conditions of the marine
life. Issues like wildlife entanglement, ingestion of plastic
by the marine animals and oiling of seabirds are harming
the whole ecosystem (Auman et al. 2014). Plastics
and microplastics have been found in the Southern
Ocean and are regularly washed up on the Heard Island
beaches. The extreme geographical remoteness of
the site limits the Australian Government’s ability to
undertake regular onsite management operations. The
site has no native or permanent residents, and hence
it faces no threats due to significant anthropogenic
activities in the region (IUCN Consultation 2020). The
threat of fishing is low, but there are chances of some
illegal and unregulated fishing within the foraging range
of albatrosses, penguins, petrels etc. (Crawford et al.
2017).
In the Australian Antarctic Strategy and 20 Year Action
Plan (Commonwealth of Australia 2016), the Australian
Government has committed to undertaking Australia’s
first formal management and scientific research visit
to Heard Island and McDonald Islands since 2004;
however, this is yet to be undertaken (IUCN World
Heritage Outlook Report 2020).
