bioluminescent plankton in Mosquito Bay

Located on the southern shore of Vieques Island in Puerto Rico, Mosquito Bay is known as the brightest bioluminescent bay in the world (declared by Guinness World Record in 2006).

This magical bay is filled with millions of dinoflagellates (or plankton-like bioluminescent microorganisms), about 1,000,000 to 2,100,000 per gallon, one of the highest concentration of them in the world. When these microorganisms are disturbed or touched by something like a boat, paddle or part of the body, they produce a bright burst of natural light (supposed to be a defense mechanism). Although they are extremely small, the size of the light they emit is a hundred times larger than their bodies.

Mosquito Bay

The bay is the perfect environment for these organisms to thrive, as the mouth of the bay is small and protect them from outer threats, and is surrounded by mangroves, they provide ideal nutrients for their survival. Please be aware that swimming in the bay is forbidden (as the chemicals we apply on our skin could harm the organisms). Instead, there are kayak and boat tours available.

The absences of pollution also helps enhance this spectacular phenomenon.

The bay is best experienced during new moon, as the absence of light allows you to maximize the bioluminescent light. It is recommended to book a tour.

There are only 5 bioluminescent bays in the world, one in Jamaica, one in Vietnam and three of them are located in Puerto Rico. The other two are the Laguna Grande in Fajardo and La Parguera in Lajas. However, these are less bright due to tourists exploitation and poor conservation.

You can learn more about vieques and how to get there here.