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The waters of Guanacaste have a secret. An organism living in the warm waters of the Pacific that can only be seen at night. Aimee knew exactly what it was; she’d seen it before.


Like fireflies, the tiny creatures light up with the gentle agitation of our hands moving back and forth in the dark water. Instantly, the phosphorescence appeared as if by magic – bluish green light emanating from our fingertips and on our faces as we splashed. We giggled like schoolgirls, delighted in our secret discovery.

There's something special in the waters off Playa Conchal Costa Rica. Living lights of ocean phosphorescence are tiny marine organisms rarely found.
The living light of marine phosphorescence in the waters off Guanacaste

The marine magic is real. Phosphorescence of the sea is the product of microscopic animals living in the ocean, generating heatless bioluminescence when disturbed. The phenomenon is especially frequent in certain tropical and temperate regions like Costa Rica, Puerto Rico, and also in the waters off of British Columbia.

The science behind the light was unknown to us as we played in the surf, marveling at the natural wonder. We invited others to share in our moment of discovery, as the secret was too good to keep to ourselves.

Lightening in the distance forced us to abandon the marine spectacle. Walking out of the ocean, we were reluctant to towel off the evidence of living light on our bodies. It’s not every day you can experience magic.

Thinking about visiting Costa Rica? Read about how to plan an awesome backpacking trip to Costa Rica.

Photo Credits: C Laroye, Flickr

Have you ever experienced phosphorescence in the ocean? What did you think was happening? Share your experience.

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