An ethereal blue glow occasionally lights up the beaches in Pingtan, becoming an online sensation and tourist magnet every April to October.

The rare natural phenomenon was first spotted in Pingtan in August 2013. Local oceanologists suggested the light was emitted by Noctiluca Scientillans, a kind of marine plankton that exhibits bioluminescence when disturbed. After some time, thrilled netizens eventually named the eerie blue glow "Sea Sparkle".

It comes once in a blue moon when the humid auster sets in on a fine evening just as the tide rises.

The phenomenon is said to exhibit various degrees of intensity ranging from speckled dots, patches, and swathes in the waters. During its weakest, the blue light is almost invisible to the naked eye, while at its strongest, a tiny ripple in the waters could light up the whole stretch of coastline.  

[Photo/Yu Min]

“Sea Sparkle” shimmers on the shore, like a blue Milky Way, beautiful to behold. Some people say the “Sea Sparkle” is something that you must see at least once in your lifetime.

"Sea Sparkle" hunt in Pingtan