A bloom of Noctiluca scintillans has lit up the seashore off Hong Kong in an eerie neon blue.

Noctiluca scintillans, also known as Sea Sparkle or Sea Ghost, is a species of dinoflagellate that exhibits bioluminescence when disturbed, such as in the crashing of waves.

Unlike similar organisms, Sea Sparkle is not harmful in itself and does not produce any neurotxins. However, blooms are a result of high concentrations of the plankton on which they feed, which is likely due to runoff from agricultural pollution, and should serve as a warning to better protect local waters and marine life.