Research recently published in the journal Current Biology determined that, in recent years, these organisms have frequently crossed oceanographic barriers to reach different islands in the Southern Ocean.
In 2018, a walk along the Fildes Bay beach on the Antarctic Peninsula became an international discovery. The researcher from the Center for Dynamic Research of High Latitude Marine Ecosystems (IDEAL) of the Austral University of Chile (UACh), Dr. Erasmo Macaya Horta, found a specimen of cochayuyo, whose scientific name is Durvillaea antarctica. Until then, the scientific literature indicated that the geographical distribution of this species only reached the sub Antarctic zone.
Four years after this scientific finding, new research published in the journal Current Biology revealed that in 2019, 25 new samples were detected on the white continent. The multidisciplinary study, led by researchers from the University of Otago (New Zealand), carried out various genomic analyzes of algae that were carried by ocean currents to Antarctica, New Zealand, Tasmania and the Macquarie Island (Australia). According to the authors of the study, the DNA of these species has confirmed how interconnected the coastal communities of the Southern Ocean are.
“The pieces found in 2018 demolished the myth that Antarctica was an isolated continent in biological terms. The analysis of almost 30 samples of seaweed that arrived in the southern territory this year alone shows that these trips are much more frequent than previously thought. They are not random events,” commented Dr. Macaya, also an academic from the University of Concepción (UdeC) and co-author of the work.
The investigation also revealed that the seaweed found on the beaches of southeastern New Zealand came from South Georgia and Marion Islands, while the specimens found in Tasmania came from the Kerguelen Islands.
According to the study, for the first time, completely reproductive algae were found, with male and female specimens, which shows that they have a high potential to complete their life cycle and colonize new territories, if environmental conditions allow it.
“I was very surprised to find so many sub Antarctic algae on the beaches of the Southern Ocean, which had already been described, but not with the frequency and abundance that we found at the time. This opens up a whole line of research and monitoring needs, especially since the fauna associated with these species are potential invaders of the Antarctic community,” said Dr. Miguel Pardo, director of the Graduate School of the Faculty of Sciences of the UACh, researcher at the IDEAL Center and co-author of the study.
“Many organisms are trying to shift their distribution to the south because it’s too hot in the north. Floating algae and their passengers can disperse very well and reach distant land masses, so they are in a very good position to colonize new territories,” said Dr Ceridwen Fraser, Research Fellow in the Department of Marine Sciences, University of Otago and author of the work. “It is an interesting challenge that we scientists will have to face. Perhaps we need to move away from the idea that conservation is about maintaining the status quo and focus on managing change to maximize biodiversity and ecosystem outcomes,” she concluded.
To read the study, click here.