See that ethereal blue glow riding the waves? While it may have caused delight to locals along Preservation Bay in Tasmania, it’s actually a sign of danger. The glow comes from bioluminescent algae called Noctiluca scintillans, known to disrupt marine food webs.
These microscopic plankton or sea sparkles as commonly known, chemically emit light when it’s disturbed, using it for protection. "It acts a bit like a burglar alarm," aquatic botanist Prof Gustaaf Hallegraeff told BBC
. "Something wants to eat you, you flash at it and then you scare it away." Sea sparkles don’t always emit just blue lights. According to a 2017 study in the Marine Pollution Bulletin, they can sometimes be green and even red just like when they bloomed in 2012 at Sydney's Bondi Beach.
While such luminous algae aren’t toxic to people and may just cause skin irritation to some, they can harm the larger part of the ecosystem. Specifically, a study published in the journal Nature in 2014
reported that low oxygen levels of water in the Arabian Sea led to three similar huge outbreaks of these N. scintillans. The blooms displaced microscopic algae, diatoms, making it the lowest link in the food chain thus, altering the entire food web. As the researchers wrote, "N. scintillans blooms could disrupt the traditional diatom-sustained food chain to the detriment of regional fisheries and long-term health of an ecosystem supporting a coastal population of nearly 120 million people.”
Though it is still uncertain how the bloom will affect Preservation Bay now, researchers are still keeping an eye on it. But hey, it’s still undeniably eerily beautiful, right? So, if you’re from the place, you can still visit the bay to catch a glimpse of its glow. Take it from the words of Brett Chatwin to the BBC, “I was gobsmacked; it was just an amazing sight."