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Bioluminescent Wonders Experience the dazzling twinkle of Puerto Rico’s glowing waters.

Glide to reveal the magic.

Puerto Rico is more than a place—it’s a feeling, a rhythm, a light that stays with you. Just like the bioluminescent bays, the Island shines in ways you won’t find anywhere else.

 

What is Bioluminescence?

Bioluminescence occurs when a living organism produces and emits light caused by a chemical reaction within it. While it is incredibly useful for animals' survival, it is also one of the most breathtaking and magical natural wonders of the world! In Puerto Rico, this phenomenon transforms the water into a shimmering spectacle, a reminder of nature’s hidden beauty waiting to be discovered.

Puerto Rico’s Bio Bays

Of the only five bioluminescent bays in the world, three are in Puerto Rico—a testament to the Island’s rich and vibrant ecosystems. These rare natural wonders are more than just breathtaking sights; they are living, glowing reminders of the delicate balance of nature and Puerto Rico’s deep connection to its waters.

 

Located in the municipalities of Lajas, Fajardo, and Vieques, these bio bays offer visitors a chance to experience something truly extraordinary. Paddling through the still waters of Mosquito Bay, gliding across Laguna Grande, or exploring La Parguera is not just an adventure—it’s an invitation to connect with nature in one of its most mesmerizing forms. The glow beneath the surface is a reflection of something greater: the Island’s beauty, resilience, and the magic that stays with you long after you leave.

Map of Puerto Rico's Bio Bays

What Are Bio Bays?

Bioluminescent bays or "bio bays" are bodies of water where microscopic organisms called dinoflagellates grow in quantities large enough to produce a "glow-in-the-dark" effect called bioluminescence. When you paddle or splash the water, these organisms shine in a neon blue-green color, making the water look as if it was lit by billions of glowing stars.

Mosquito Bay in Vieques is one of the brightest bioluminescent bays in the world

Puerto Rico Bay

Laguna Grande in Fajardo is technically not a bay but a lagoon, and it is the closest to San Juan

Glowing Bioluminescence
Hand in water at a bioluminescent bay.

Shaking up the dinoflagellate organisms in a bioluminescent bay will feel like playing with stars.

The bio bay at La Parguera, located in Lajas, allows swimming and scuba diving.

Dos and Don'ts of Visiting the Bio Bays

Plan your visit to Puerto Rico’s enchanting bio bays with care. Our do’s and don’ts offer essential tips to help you protect and enjoy this natural wonder.
DO

keep an eye on the moon phases and try to avoid the full moon. The darker, the better!
DON'T

bring your camera or other electronic devices, and avoid bright lights.
DO

call ahead to make sure that the bay's brightness has been above 30% before visiting.
DON'T

litter. It’s important to do what we can to preserve the dinoflagellate’s ecosystem so others can enjoy the “light show.”
DO

wear comfy clothing for paddling, as most bays use kayaks.
DON'T

wear lotions, hand creams, sunscreens, or any products that could cause harm to the organisms.
DO

stick to designated paths and respect the wildlife!

Conservation Efforts in the Bio Bays

Types of Bio Bay Trips

Traveling to the Island’s bio bays is the recipe for unforgettable memories and a great option for different types of travelers.

Solo Traveler

With several tour options, you don’t need to be part of a group to visit. It’s also a great way to meet people with similar interests.

Event Organizer

What conference attendees can say that they experienced the magic of bioluminescence during their corporate seminar?

Couples

There’s nothing more romantic than a nighttime boat ride among glowing waves!

Family

Name a better family bonding time — staying up past their bedtime is also a fun bonus. 

How many bioluminescent bays are there in the world?

There are about five year-round bio bays worldwide, and many others will pop up with the seasons as the conditions required to maintain a high enough number of dinoflagellates is a tight balance. Puerto Rico is home to three of those year-round bio bays because the Island’s biodiversity has the necessary ingredients to keep those population numbers!

What is special about the bioluminescent bays in Puerto Rico?

Puerto Rico’s bio bays are unique for several reasons, in no small part because there are three of them, and they are year-round. Additionally, the Island’s bio bays have three key factors that ensure their glow: narrow entrances that keep salinity high, shallow waters that keep the dinoflagellates concentrated, and tidal waters that help them stay replenished.

Are bioluminescent bays safe to swim in?

The bio bays in Puerto Rico are safe to swim in since the variety of dinoflagellate they contain, the Pyrodinium bahamense is non-toxic. However, swimming isn’t allowed in Mosquito Bay and Laguna Grande, but it is permitted in La Parguera.

What makes bioluminescent bays glow?

The glowing you see is caused by tiny microorganisms called dinoflagellates, also known as dinophytes. These microorganisms contain luciferin, similar to chloroform, which reacts with oxygen to produce the blue glow. These microorganisms use light as a protection method, triggering that chemical reaction when you gently move the water.

When are the bioluminescent bays in Puerto Rico brightest?

The bays are brightest during a new moon and warm, calm nights with little winds and rain. For that reason, the summer and fall are great times to see them because that’s when these weather conditions are most common. That said, their brightness can fluctuate greatly due to tidal movement and salinity, so don’t let the time of year discourage you!

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