A surprising sight was seen on the coast facing the Yatsushiro Sea in Amakusa, Kumamoto Prefecture in southwestern Japan. 

The water has turned to a brilliant pink color… 

If you look closely, it appears that something pink is mixed in with the seawater. 

The change happened on the evening of April 17. 

At night, it appears quite differently. 

The surface of the sea glows blue in synch with the movement of the water. 

Standing at the water’s edge, it looks like blue waves are washing in. 

If you stir up the waves, you can watch a ring of light spread… 

What could this mysterious phenomenon be, that appears differently during the day and at night? 

S/ Samejima Mamoru,  Deputy Director of Kumamoto Prefectural Fisheries Research Center:  

This is definitely noctiluca. 

Noctiluca, a plankton that glows when stimulated. 

The day before the sea turned pink, a large amount of noctiluca were found about 15 kilometers away, and are believed to have flowed in. 

The noctiluca disappeared the next morning but reappeared in the evening. 

There may still be a chance to see this kind of breathtaking scenery.