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  • Writer's pictureWorld Half Full

Macquarie Island still pest-free ten years after

ENVIRONMENT/ANIMALS



As Andrea Turbett looks out over the steep, green slopes of Macquarie Island, she’s filled with a sense of pride. “It’s such an immense privilege to watch [the island] recover,” says the Tasmania Parks and Wildlife Service manager.


Less than 20 years ago, the tiny outcrop in the middle of the Southern Ocean was facing an environmental crisis caused by a plague of pests. But a radical plan involving millions of dollars and years of dedication has resulted in an extraordinary transformation of the World Heritage-listed island.


“I think some people didn’t quite realise how ambitious [the plan] really was,” Turbett says. “And it really was a miraculous achievement because of all the different challenges that were thrown up to the project.”


Rabbits, rats, mice and cats began to proliferate on the remote island following the arrival of explorers in the 1800s. And the impact was devastating.


Two endemic birds — the Macquarie Island parakeet and Macquarie Island rail — became extinct, and by the early 2000s, more than a dozen others were under serious threat. The island’s tussock grasslands and mega-herbs had also become severely degraded, with widespread erosion resulting in the loss of vital habitat for nesting seabirds.


But a decade after the world’s largest pest eradication program, Macquarie Island is returning to its former glory. “Now it’s flourishing with mega-herbs, cabbage [and] the tussock we have all around, and it’s just incredible everywhere,” Turbett says. “It's definitely been an excellent result that everyone’s really proud of.”


The $24-million program, jointly funded by the Tasmanian and Australian governments, kicked off in 2007. Calicivirus was released on the island in 2011, followed by a combination of aerial baiting, shooting and hunting dogs. This approach saw the removal of more than 125,000 rabbits and countless rodents.





By 2014, the island was declared pest-free, with no introduced species spotted in the previous two years.


“The vegetation recovery that we are seeing with the removal of rabbits is absolutely extraordinary,” says wildlife biologist Kris Carlyon. “We ended up walking through tussock at the bottom of some of the slopes that was twice as high as my head. It was quite amazing to see.”


While the baiting program resulted in the unintended deaths of some birds, including giant petrels and skuas that fed on dead rodents, Dr Carlyon says the long-term benefits for the island were clear.


“This eradication effort was the largest eradication of rodents undertaken anywhere in the world, so it was a huge feat to pull off,” he notes. “The efforts were completely validated in my view. We’re seeing just such outstanding results now.”


To keep the island pest-free, a range of protocols are in place, including biosecurity dogs to check cargo before it’s sent on ships travelling to the island.


Australian Antarctic Division spatial ecologist Aleks Terauds believes ongoing monitoring of the island’s flora and fauna is still imperative. “Without this long-term data, it’s really hard to identify change,” he says. “At the moment, we’re seeing change in relation to the vegetation improving. But we’ve got climate changes on Macquarie Island, we’ve got the spectre of avian influenza. And without this monitoring, we really can’t understand what the trajectories are and what we can do to help manage it.”


Last year, the Australian government committed $380,000 to fund ongoing monitoring.


TOP Andrea Turbett amidst a “flourishing” island

PHOTO AAD/Pete Harmsen

ABOVE Before pest eradication

PHOTO AAD/DanaBergstrom

MIDDLE After eradication

PHOTO AAD/Pete Harmsen

BOTTOM Shoreline

PHOTO AAD/Pete Harmsen


This eradication effort was the largest eradication of rodents undertaken anywhere in the world, so it was a huge feat to pull off. The efforts were completely validated in my view. We’re seeing just such outstanding results now.

Kris Carlyon


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