The sea in Tasmania’s Preservation Bay has been glowing bright blue, much to the awe and delight of its visitors.
The glow is caused by single-celled algae or plant plankton called Noctiluca scintillans, which illuminate when waves or currents disturb them. Gustaaf Hallegraeff, a professor in aquatic botany at the University of Tasmania, told the ABC that the algae flashes as a defence mechanism, “There’s actually evidence that shows if you offer an animal a choice between a luminescent plankton and a non-luminescent plankton, they avoid the luminescent one,” he said.
While the phenomenon is not harmful to humans, it can still pose a threat to biodiversity as the plankton move on en masse and consume other food sources. “This is an organism that eats other species,” explains Professor Hallegraeff. “So if there is a huge amount of it, and basically it behaves like a vacuum cleaner and it eats away at the other plankton.”
Still, there is no doubt that the phenomenon makes for incredible viewing. “It exposes people to the wonder of nature, and they should be able to enjoy that,” says Professor Haellegraeff. “It’s spectacular.”
