Researching the control of invasive species in the fragile sub-Antarctic

Published 03 February 2015

Macquarie IslandIn the wild waters of the Southern Ocean, halfway between Tasmania and Antarctica, lies the tiny, sub-Antarctic speck of Macquarie Island – an island that is under threat from invasive species.

The control of these invasive species is the subject of new research being undertaken by the University of New England in a bid to protect the fragile ecosystem and abundant populations of wildlife and seabirds.

University of New England PhD candidate Laura Williams has spent the past two summers on Macquarie Island studying the most common alien plant species in the sub-Antarctic, Poa annua or ‘Wintergrass’, which has been widely spread by humans and wildlife.

Laura says Poa annua competes with native plant species, many of which are found nowhere else on Earth.

“On Macquarie Island, which is well known for the recent eradication of all rats, rabbits and mice, there are only three alien plant species, and Poa annua is the most common and widespread,” Laura said.

“While it is unlikely that Poa annua can be eradicated from Macquarie Island altogether, we are studying the ecology and potential control methods of this plant in the hope that control of the species will be possible in parts of the sub-Antarctic and Antarctic.”

Laura, who plans to return to Macquarie Island in April, says this study is important to understand more about threatening invasive species in the sub-Antarctic.

“Studying factors such as the lifespan of this plant, its impact on native species, and how we might be able to control its abundance is essential to improving our knowledge of invasive species in sub-Antarctic ecosystems.

“This is especially important in light of future climate change and increased visitation to the Antarctic region, both of which are predicted to increase the distribution and spread of alien species,” Laura said.