A stunning natural phenomenon called "blue tears" illuminated the sea off Pingtan Island in east China's Fujian Province on Saturday.

Luminescent blue spots appeared in the waves and along Pingtan's beaches, lighting up like a mini-Milky Way and lapping at onlookers' feet.

The phenomenon is a chemical reaction caused by two types of sea organisms, cypridina and noctiluca scientillans. It usually occurs between May and October, but its appearance this year was a little early, according to locals.

When stimulated by the external environment, cypridina will excrete luciferin and luciferase into the water, resulting in a chemical reaction. In addition, noctiluca scientillans, a type of red tide organism found in all seas, can produce bioluminescence in turbulent water, which explains why the sea can give off bluish light.

Pingtan's location with special currents and tides gathering in that spot also contributes to the effect.  

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