Cozumel’s Glowing Waters Are Disappearing—Here’s Why

Cozumel, Mexico — When night falls in the Caribbean, Cozumel transforms from a paradise of beaches into an island that glows—not from artificial lights, but from a natural chemical reaction produced by living organisms. This magical display of natural light occurs under ideal conditions: a starry sky and warm waters. It is one of nature’s most spectacular phenomena: bioluminescence in Cozumel.

The bioluminescence in Cozumel is caused by tiny marine organisms such as dinoflagellates, which turn the sea into a mesmerizing dance of shimmering lights. However, this phenomenon should not be viewed merely as a tourist attraction. There is an urgent need to protect marine ecosystems, and the bioluminescence in Cozumel serves as a call to safeguard one of the planet’s most beautiful and fragile environments. The proposed construction of a fourth cruise ship pier in Cozumel could prove devastating.

What Is Bioluminescence?

Bioluminescence is a natural chemical reaction in which living organisms along coastlines and reefs emit their own light. In Mexico, this phenomenon is primarily caused by organisms such as dinoflagellates, jellyfish, bacteria, and certain species of crustaceans or fish. The light is produced through internal chemical reactions.

The bioluminescence in Cozumel is particularly striking due to the clarity of its waters and the richness of its marine ecosystem, which is part of the Mesoamerican Reef System (SAM).

Bioluminescence and Reefs in Danger: The Spectacle We Could Lose

However, the bioluminescence in Cozumel is under threat due to unchecked tourism development, particularly from mass cruise tourism. Since the construction of the first pier in the 1970s, pressure on the reefs has grown exponentially. Today, the proposed fourth pier has raised concerns among scientists, environmentalists, and local residents.

According to data from the 2022 Atlantic and Gulf Rapid Reef Assessment (AGRRA), more than 97% of coral populations near the three existing piers have already died. This not only harms the ecosystem but also jeopardizes the future of bioluminescence in Cozumel. If corals die, many bioluminescent and fluorescent species will disappear.

One such species at risk is Ophionereis commutabilis, a marine species endemic to Cozumel. Discovered in 2020 by scientists from the Institute of Marine Sciences and Limnology at the National Autonomous University of Mexico (UNAM), its origins trace back to prehistoric times.

Responsible Tourism: The Key to Protecting Bioluminescence in Cozumel

To prevent the loss of bioluminescence in Cozumel, promoting responsible tourism is essential. Governments, businesses, and residents must work together to avoid uncontrolled infrastructure expansion, such as the proposed fourth pier.

For Greenpeace, it is vital that Cozumel becomes an environmental priority in Mexico. Preserving bioluminescence is not just about protecting glowing species—it is about sustaining entire ecosystems. Although the fourth pier project is currently under review by Mexico’s Ministry of Environment and Natural Resources (SEMARNAT), the threat remains.

Greenpeace urges the public to remain vigilant and join the effort to protect this incredible ecosystem. The organization calls on supporters to voice their opposition to the fourth pier in Cozumel.

Mass tourism is dimming the sea’s natural glow. Protecting marine life requires action today.