[BRIEF NOTE] Poor Macquarie island

[rfmcdonald]

While idly reading about the Antarctic region on Wikipedia yesterday, I happened upon the entry for Macquarie Island, a subantarctic island roughly midway between New Zealand and Antarctica that's under Australian jurisdiction. We've managed to inflict numerous ecological horrors on that isolated island with its unique ecology, of course.

The ecology of the island was affected soon after the beginning of European visits to the island in 1810. The island's fur seals, elephant seals and penguins were killed for fur and blubber. Rats and mice that were inadvertently introduced from the ships prospered due to lack of predators. Cats were subsequently introduced deliberately to keep the rodents from eating human food stores. In about 1870, rabbits were left on the island by sealers to breed for food. By the 1970s, the then 130,000 rabbits were causing tremendous damage to vegetation.^[4]

The feral cats introduced to the island have had a devastating effect on the native seabird population, with an estimated 60,000 seabird deaths per year. From 1985, efforts were undertaken to remove the cats. In June 2000, the last of the nearly 2500 cats were culled in an effort to save the seabirds.^[5] Although seabird numbers began to rise initially, the removal of the cats allowed a rapid growth in the number of rats and rabbits which together are causing widespread environmental damage.

The rabbits rapidly multiplied before numbers were reduced to about 10,000 in the early 1980s when myxomatosis was introduced. Rabbit numbers have grown again to around 100,000 on the island.^[6] The rodents feed on young chicks while rabbits nibbling on the grass layer has led to soil erosion and cliff collapses, destroying seabird nests. Large portions of the Macquarie Island bluffs are eroding as a result. In September 2006 a large landslip at Lusitania Bay, on the eastern side of the island, partially destroyed an important penguin breeding colony. Tasmania Parks and Wildlife Service attributed the landslip to a combination of heavy spring rains and severe erosion caused by rabbits.^[7]

Research by Australian Antarctic Division scientists, published in the 13 January 2009 edition of the British Ecological Society's Journal of Applied Ecology, showed that the success of the feral cat eradication program has allowed the rabbit population to increase, damaging the Macquarie Island ecosystem by altering significant areas of island vegetation.^[8]

On 4 June 2007 a media release by the Australian Federal Minister for the Environment and Water Resources, Malcolm Turnbull, announced that the Australian and Tasmanian Governments had reached an agreement to jointly fund the eradication of rodent pests, including rabbits, to protect Macquarie Island's World Heritage values.^[9] The plan, estimated to cost $24 million Australian dollars, will involve mass baiting the island similar to an eradication program on New Zealand's Campbell Island^[10] and is expected to take up to seven years.^[11]

There's something almost funny in the one-after-the-other chain of ecological catastrophes, isn't there?