Antarctica vulnerable to invasive species on floating debris: study

SYDNEY, Aug. 22 (Xinhua) — Antarctica could be vulnerable to invasive species carried to the continent on floating plastic and organic debris, according to new oceanographic modeling.
In a new research published on Thursday, researchers led by a team from the University of New South Wales (UNSW) in Australia found that floating objects can reach the Antarctic coastline from all southern continents.
The finding triggered a warning that non-native species could be carried to Antarctica on floating objects including plastic, kelp and driftwood and dramatically change marine ecosystems in the region.
Hannah Dawson, who led the research as part of her PhD at the UNSW and is now based at the University of Tasmania, said that it was previously thought that debris only drifted to Antarctica from remote and unpopulated islands in the Southern Ocean.
However, by building an oceanographic model based on surface current and wave data from 1997 to 2015 the research team found that floating debris reaches Antarctica from various Southern Ocean land sources every year.
Dawson said in a media release that an increasing abundance of plastics and other human-made debris in the oceans means more opportunities for non-native biota to reach Antarctica.
“We knew that kelp could raft to Antarctica from sub-Antarctic islands, such as Macquarie and Kerguelen Islands, but our study suggests that floating objects can reach Antarctica from much further north, including South America, New Zealand, Australia, and South Africa,” she said.
“The shortest time it took for particles to reach the Antarctic coastline was from Macquarie Island, south of New Zealand, some of which arrived in just under nine months. On average, the longest journey was for objects released from South America.”
The study was co-authored by researchers from the Australian National University, the University of South Florida in the United States and New Zealand’s University of Otago.
They found that most of the rafting objects arrive at the tip of the Antarctic Peninsula — a region with relatively warm ocean temperatures and regular ice-free periods — making it a likely area for non-native species to first establish on the continent. ■