HONG KONG, Jan. 27 (UPI) -- The waters of Hong Kong's harbor are sparkling a bright electric blue at night, as boats and thrown stones send ripples through the growing mats of Sea Sparkle. And local photographers there have been capturing the surreal phenomenon.
Sea Sparkle (Noctiluca scintillans) is a species of dinoflagellate, single-cell microorganisms that collect in algae-like blooms in the ocean. The blooms of phytoplankton often make up what are referred to as a red tide, though red tides can include the amalgamation of all kids of algae species.
Sea Sparkle, like most red tide organisms, is red or brown in color in the light of day, but its bioluminescence gives it a bright blue glow at night. The algae's bioluminescence is only triggered when the water is disturbed.
"You can see the blue light if there is a wave, a boat moving, or a stone thrown in the water," Lit Wai Kwong, a local photographer, told CNN. "There was no blue light when the water was calm, therefore many people threw stones into the water in order to see it."
While this particular algae bloom doesn't give off toxins, it can threaten marine life if it grows too large. Expansive mats of dinoflagellates can suck oxygen from the water, squeezing out vulnerable species and momentarily wreaking havoc on local food chains.
Large algae blooms are prone to expansion when waters are particularly warm and typically congregate in places where fertilizer-rich runoff waters feed into the ocean.
"Hong Kong and the entire Pearl River Delta has a big problem with wastewater, and that is surely a factor with these plankton blooms," David Baker, a researcher at the Swire Institute of Marine Science at the University of Hong Kong, told CNN.
"I guess the analogy is they're like locusts that feed on agricultural crops," Baker added. "And once they find a good abundant food source they will multiply until the food source is exhausted. In Hong Kong unfortunately most of the nutrients are coming from our own sewage."
In the United States, red tides in the Gulf of Mexico regularly haunt the coasts of the Southeast, as massive amounts of fertilizer runoff makes its way down the Mississippi and congregates in open water.