MELBOURNE, Feb. 23 (Xinhua) -- Antarctic scientists in Australia have trialed a DNA "barcoding" technique that could help prevent invasive marine species from reaching polar ecosystems.
Researchers from the Australian Antarctic Program (AAP) used environmental DNA, or eDNA shed by all organisms into the environment, to detect species known to hitch-hike on ships' hulls during a 2022 voyage from the island state of Tasmania to sub-Antarctic Macquarie Island, an AAP statement said Monday.
The research, published in Science of The Total Environment, showed that eDNA sampling could help ensure effective biosecurity practices, such as hull cleaning, and identify invasive species before they can establish, said AAP molecular biologist Leonie Suter from Australia's University of Tasmania.
"By collecting environmental samples, such as soil or water, we can analyze this DNA and identify what organisms are present," Suter said.
The research showed that eDNA monitoring could validate biofouling management to protect sub-Antarctic and Antarctic marine environments.
To collect the eDNA samples, the team used small sponges contained inside perforated plastic balls, to absorb seawater containing DNA fragments shed by organisms.
Visual checks identified 24 species attached to the ship hull, while eDNA detected 41, including worms, sea stars, molluscs, sponges, algae, crabs and sea squirts, the study showed.
Researchers found evidence of hull-associated species both in the waters of the Tasmanian state capital Hobart and around Macquarie Island.
"Additional assessments, such as visual surveys and further sampling, are needed to determine whether living organisms are transported on the ship's hull, and whether they could pose a risk to the environment," Suter said.
The researchers said eDNA monitoring offers a valuable new tool as climate change and increased human activity heighten biosecurity risks. ■