This luminescent blue glow in these waters around Hong Kong is the rsult of an algal bloom created by Noctiluca scintillans – also known as “sea sparkle.” Wave action or currents cause Noctiluca scintillans to glow.
It’s beautiful, but it’s also toxic. Run-off pollution from farms increases levels of nitrogen and phosphorous, which leads to Noctiluca scintillans, which in turn leads to dead zones:
But Noctiluca scintillans can be lethal to plants and animals. Scientists think the dead zone was created when the species killed off native algae and compromised the fish population. Gwynn Guilford of Quartz wrote: “Few animals can survive ‘dead zones’ of oxygen-poor water. As the scientists discovered, N. scintillans thrives in these conditions…. And once a dead zone sets in, it’s hard for the ocean to recover.”