Amazing Places

Mosquito Bay Is Teeming with Eerie, Glowing Plankton

Have you ever wanted to kayak in the glow of the moonlight? Well, this Caribbean island just off the coast of Puerto Rico called Vieques can do you one better. This little gem is home to Mosquito Bay, the brightest bioluminescent bay in the world. That's right: it's a bay with glow-in-the-dark water. How is that possible? The water is full of a species of plankton with special properties that cause them to blaze with blue light — and even hurricanes aren't enough to dim their dazzling glow.

Thar She Glows!

Allow us to introduce you to Pyrodinium bahamense, the little critters responsible for lighting up Mosquito Bay. Categorized as dinoflagellates, a type of marine unicellular plankton, their name translates to "swirling fire." Whenever they're agitated by the touch of water currents or even by bumping into each other, they produce a light that spreads to more than 100 times their size. Despite the fact that Pyrodinium bahamense isn't physiologically the brightest bioluminescent species out there, Guinness World Records named this Bio Bay the brightest in the world in 2008. That's because Mosquito Bay has the largest concentration of these glowing sea creatures — about 700,000 per gallon of water.

Don't let the name turn you off: it's not called Mosquito Bay because it's overrun by bloodsucking insects. It's actually named after "El Mosquito," a small ship owned by Roberto Cofresí... better known as "El Pirata Cofresí." Yes, you read that correctly: he's a pirate. Known for his Robin Hood-esque "good thief" pirate practices, Cofresí often hid El Mosquito in the bioluminescent bay since it connected to the ocean through a small inlet.

Agitating the waters of Mosquito Bay causes bioluminescent plankton to glow blue.

A Dimming Light

Like many natural, beautiful things, Mosquito Bay is fragile. In September 2017, Puerto Rico was battered by Hurricane Maria, its worst natural disaster on record. The storm did a lot of damage to Mosquito Bay: the rain threw off its delicate chemistry and the winds damaged the nutrient-rich mangroves that surround it and blew the tiny glowing creatures out to sea. As a result, the bay went dark and stayed that way for weeks. But just months later, NPR reported, you could see flickers of light. Mosquito Bay's dinoflagellates were coming back to life.

Hurricanes aren't their only threat, though. Back in the day, locals swam in the bioluminescent water whenever they pleased, but the recent influx of visitors is believed to be slowly affecting the bay's overall brightness. All the shampoos, lotions, and perfumes we use seem to be damaging the dinoflagellates. Even if the bay bounces back to its original glory, you won't be able to take a dive into the glowing water. But you can dip your hands and feet in from your kayak. That's still pretty good in our book.

The Glowing Bio Bay In Vieques, Puerto Rico

Written by Sam Suarez May 16, 2017

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