Aliens in an Ancient Landscape: Rabbits, Rats and Tourists on Macquarie Island
Macquarie Island, in the subantarctic south of Tasmania, Australia, is one ofthe few refuges in the vast Southern Ocean for seabirds, seals and penguins.Their presence contributes nutrients to the substrate upon which coldtemperature flora, grasses and mega-herbs (but not trees), rely. Exotic animal...
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| Format: | Book Part |
| Language: | English |
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CABI
2011
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| Online Access: | http://www.cabi.org/bookshop/book/2255 http://ecite.utas.edu.au/78244 |
| Summary: | Macquarie Island, in the subantarctic south of Tasmania, Australia, is one ofthe few refuges in the vast Southern Ocean for seabirds, seals and penguins.Their presence contributes nutrients to the substrate upon which coldtemperature flora, grasses and mega-herbs (but not trees), rely. Exotic animalssuch as elephant seals and king penguins, plants and, more generally, thephysical vista of the island, are integral to the island tourism experience. Thesustainability of Macquarie Island tourism relies in large part on the continuedexistence of an experience of this calibre and therefore its fortunes are tied tothe fortunes dictated by the physical processes that continue to shape theisland. Tourism is not a major contributing factor to island disturbance, but itmay be a hapless victim of these physical changes. The sustainability of futuretourism to Macquarie Island is discussed here in the context of contemporaryphysical changes to climate and the resulting ecological effects. Hundreds of thousands of years ago, oceanic crust that was about 9 millionyears old was thrust out of the Southern Ocean and Macquarie Island wasborn. It is the only one of the subantarctic islands (Fig. 2.1) to be formed in thisway, and earned it World Heritage Area status in 1997. Its modern historybegan with its discovery by sealers only 200 years ago; there followed a grizzlyhistory of mass slaughter of its wildlife, particularly of seals and penguins,which were clubbed to death or driven alive into trypots and boiled for their oil(Parks Tasmania, 2009a). The legacies from the island's first visitors are adouble-edged sword. Macquarie Island 's unusual genesis and the abuse of itswildlife have earned it a host of prestigious designations as a place of outstandinguniversal value, giving significant protection to its biodiversity. The downsidehas been the intentional and accidental introduction of non-native species.Today there is evidence of the significant effect of these aliens (especiallyrabbits and rats) on the endemic flora and fauna. This, in turn, threatens tocompromise the island's appeal as a tourist destination in its own right and asa stepping-stone for tourism to East Antarctica. The early 21st century is a time of transitional climate warming, with theeffects being noted first on the subantarctic islands. Early indications, althoughstill somewhat ambiguous, point to the possibility of more extreme localweather conditions, which are already extreme in the subantarctic; conditionsthat are more conducive to the survival and colonization of introduced species,including microorganisms, with the resultant biosecurity issues; and changingclimatic conditions, making Macquarie Island, for example, even wetter andpossibly less appealing to all but the hardy few (Pendlebury and Barnes-Keoghan,2007). Fragile is not an adjective that is usefully applied to this or the othersubantarctic islands that have stood in the path of keening winds, driving rainand chilling temperatures for millennia. Their plants and animals are relativelyrobust, otherwise they would not have survived in what humans would call an extreme environment. However, these remote subpolar ecosystems are mostcertainly vulnerable and, in contemporary times, it is the introduction of alienspecies in a warming climate that will continue to have the greatest effect. Itwill be impossible for the administrators of any of the subantarctic islands.including Macquarie Island, to ameliorate extrinsic factors, such as the effectsof climate warming, but it is possible to manage and regulate intrinsic factorssuch as the introduction of alien vertebrates and human activity. If the ecologicalintegrity of Macquarie Island can be maintained relatively free fromanthropocentric stressors, then there will be a better chance of withstandingthe pressure from sources that cannot be controlled. |
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