When Chilean researcher Erasmo Macaya stumbled upon foreign kelp washed up on an Antarctic beach, he knew he had found something significant. With an international team, including Utrecht oceanographer Erik van Sebille, Macaya found out that the kelp had drifted 20,000 km to the Antarctic shore: the longest known biological rafting event ever recorded. The results are published in Nature Climate Change on 16 July.
To get to Antarctica, the kelp had to pass through barriers created by polar winds and currents that were, until now, thought to be impenetrable. It means Antarctica is not as isolated from the rest of the world as scientists have thought, which has implications for how Antarctic ecosystems will change with global warming.
The results might have implications for floating plastic debris too. While there are few sources of plastic litter on Antarctica itself, there are garbage patches in the South Atlantic and South Pacific, just a few 1000 km north of Antarctica. “The storms and Stokes drift that transport the kelp could also transport plastic debris to Antarctica, putting extra pressure on the vulnerable ecosystem there”, says Erik van Sebille of Utrecht University. “This is something we need to find out urgently.”