By Mari Hansen After dark, a certain kind of silence descends upon Mosquito Bay in Vieques, accompanied only by the sound of frogs playing in the mangroves and the soft slap of a paddle against still water. The bay was hardly glowing on the night a reporter paddled out there for the first time, months after Hurricane Maria devastated the island.
A hand that had been dipped left behind a faint shimmer, perhaps a two out of ten. It resembled a patient recuperating in a hospital bed, blinking its eyes for the first time in weeks, rather than a natural marvel.
| Category | Details |
|---|---|
| Location | Mosquito Bay, Vieques, Puerto Rico |
| Bay Type | Bioluminescent lagoon |
| Primary Organism | Pyrodinium bahamense (dinoflagellates) |
| Glow Color | Blue-green |
| Named After | A legendary pirate ship |
| Island Size | Approximately 8 miles off the coast of Puerto Rico |
| Key Threat Events | Hurricane Maria (2017), chronic pollution |
| Global Bioluminescent Bays | Fewer than a handful remain worldwide |
| Research Body | Centro TORTUGA / Maryland Sea Grant / NSF |
| Conservation Group | Vieques Conservation and Historical Trust |
| Ecotourism Operator | Black Beard Sports, Vieques |
| Further Reading | UMCES Horn Point Laboratory |
Located on the tiny island of Vieques off the eastern coast of Puerto Rico, Mosquito Bay has long been known as one of the world’s brightest bioluminescent bays. Locals claim that a fish’s glowing wake can be used to track it on good nights.
The entire bay is said to become a lit chandelier when rain hits the surface. To paddle out and run their fingers through living light, tourists travel from all over the world. Without shame, both researchers and guides refer to it as magic.
The magic vanished when Maria struck in September 2017. The mangroves that surround the bay were battered by the storm; these mangroves provide vital vitamins to the single-celled organisms that produce the glow, a species known as Pyrodinium bahamense, or “the whirling fire of the Bahamas.”
The delicate chemical balance of the bay was upset by the storm’s surge of fresh water. High winds probably forced the glowing plankton out through the bay’s mouth and into the open ocean, according to guides like Angie Hernandez of Black Beard Sports. The water appeared normal for weeks.
Since then, researchers have been assembling a more accurate picture of the true fragility of this chemistry. Mosquito Bay’s illuminating dinoflagellates are more than just ornamental. As a defense mechanism, they glow, a flash that could warn larger predators of whatever creature is bothering them.
This is an incredibly intricate chain reaction for a single cell. Bioluminescence expert and co-founder of the Ocean Research and Conservation Association Edith Widder has called the behavior “spectacular,” which seems like an understatement if you’ve ever witnessed it.
Researchers like Widder and a group from the University of Maryland Center for Environmental Science have been delving deeper into the question of why bays like this one exist in the first place and why so few of them survive.
Following the hurricane, Mark Martin-Bras, the director of research at the Vieques Conservation and Historical Trust, spent weeks collecting water samples and monitoring the numbers. Timelines were a source of caution for him.
After earlier storms, the bay had also dimmed, and recovery was never quick or straightforward. However, he claimed that there was a feeling that the marine environment has a stubborn survival instinct of its own. To a certain extent, it cleans itself. How near that point is to the edge is always the question.
It turns out that the slower erosion occurring in between storms is what worries scientists more than hurricanes. For decades, bioluminescent bays around the world have been steadily declining due to pollution, which includes waste, chemical runoff, and substances released into water with little knowledge of their downstream effects.
These locations are not nearly as bright as they once were, to put it simply, according to Widder. any of them. That is not a tale of a storm. It’s a slow, drawn-out one, and it’s still unclear if it has a better conclusion.
Recently, sixteen undergraduates from two Puerto Rican universities joined researchers to conduct a more thorough investigation of the bay’s ecology, focusing not only on the activities of the dinoflagellates but also on why they are unique to these lagoons.
The National Science Foundation-funded research project Centro TORTUGA is the type of work that is typically overlooked outside of academic circles. However, the questions it poses—why here, why so dense, why so persistent—seem more pressing than they did prior to the storm.
Observing all of this, it’s difficult to ignore the fact that the bay’s recovery has mirrored a more significant aspect of Vieques. After Maria, Hernandez didn’t have running water for weeks. Bookings from tourists virtually vanished.
The bay served as the island’s main draw, attracting tourists and sustaining its economy. It wasn’t just economic; it also had psychological effects when it went dark. She described it as an indescribable relief to see the first faint trails of light reappear in the water.
After years of dimming, Puerto Rico’s bioluminescent bay has reappeared, and scientists now have a better understanding of why than before the storm. It is genuinely unclear if this knowledge will result in improved protection against pollution, exploitation, and the next Category 4. There’s no doubt that losing this place completely and forever would be a different kind of loss than most. Not merely a vanished tourist destination. Something older and stranger than that.