How Did This Puerto Rican Bay Lose Its Glow?

A rare wonder of nature has mysteriously stopped glowing. And this has some local residents worried about how they’re going to make a living.

Located in Fajardo, Puerto Rico, Laguna Grande is one of the world’s few bioluminescent bays. At night its waters glow like blue neon lights when they are stirred by boats, humans, or marine creatures.

For the past couple decades Laguna Grande —which is marketed in tourist websites as the “bio bay” — has been a popular destination for ecotourists, eager to take a swim in its surreal waters. But for the past nine days the “bio bay” has stopped glowing and locals are concerned.

A tourist swims at a bioluminescent bay in Vieques, Puerto Rico. [Nipunscorp.com]

“We’ve been organizing tours to the lagoon for 16 years, and we’ve never seen it stop glowing from one day to another,” tourist operator Nestor Martinez told the EFE news agency.

“On Saturday [Nov. 9] we did a tour, we rested on Sunday and when we came back on Monday the lagoon had turned itself off,” Martinez said.

According to EFE there are 11 companies currently offering boat and kayak tours of the lagoon, and up to 700 jobs in Fajardo benefit from bio bay tourism.

The lagoon’s glow is created by its large population of dinoflagellates, a special type of plankton that inhabits its waters.

While ocean currents and changes in the weather can affect the abundance of this plankton, locals suspect that two water treatment plants that are being built on the lagoon’s shores could be responsible for the current “blackout.”

The mayor of Fajardo has summoned a team of biologists to study why the lagoon has stopped glowing.

But locals complain that construction is still going on at the water treatment plants, which are owned by Puerto Rico’s National Aqueducts Agency.

“They should stop building those plants until we determine what effect they’re having,” tourist operator Nestor Martinez told EFE.

Puerto Rico has two more bioluminescent lagoons, which are currently glowing just fine. You can read more about them here and here.

Manuel Rueda is a correspondent for Fusion, covering Mexico and South America. He travels from donkey festivals, to salsa clubs to steamy places with cartel activity.