An unforgettable scene in the 2012 movie "Life of Pi" featured a boat floating in glowing sea water. This phenomenon isn't fiction – it happens in China.

It occurs between April and August in temperate, subtropical and tropical coastal areas. Onlookers have given it the beautiful name of "blue tear".

This is caused by the bioluminescence of plankton. Their luminous organs react to certain stimulation, like the wave or a swimmer passing them in the sea, and when this pushes the plankton to the shore or onto rocks, it looks like it is crying "blue tears."

Though the "blue tear" is beautiful, because it shows high activity of algae and plankton along the seashore, it can lead to a "red tide." Thankfully, none of these creatures are toxic, but it is still recommended that you stay away from the luminous sea water as it is likely to cause an allergic reaction.

(Cover image via VCG)

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