Beautiful but Toxic 'Sea Sparkle' on the Rise

Eerie fluorescent blue patches of water seen glimmering off Hong Kong's seashore are magnificent, disturbing, and potentially toxic, marine biologists say. The glow is an indicator of a harmful algal bloom created by something called Noctiluca scintillans, nicknamed "Sea Sparkle." It looks like algae and can act like algae, but it's not quite: It's a single-celled organism that technically can function as both animal and plant. These blooms are triggered by farm pollution that can be devastating to marine life and local fisheries, says University of Georgia oceanographer Samantha Joye.

"Those pictures are magnificent. It's just extremely unfortunate that the mysterious and majestic blue hue is created by a Noctiluca," Joye says. This is part of a problem that's growing worldwide, according to Joye and other scientists. Noctiluca is a type of single-cell life that eats plankton and is eaten by other species. Unlike similar organisms, Noctiluca doesn't directly produce chemicals that can attack the nervous system or parts of the body, but scientists say its role as both prey and predator can eventually magnify the accumulation of algae toxins in the food chain. (More marine biology stories.)