It’s midday off the coast of Cancún, Mexico. You’re on a boat getting ready for a reef dive. You check your gear one last time, then tip backward off the boat into the clear, cool water.


As you swim down, you start to see somethingsomething near the seabed. You continue your descent to nearly 10 meters (32 feet). And there, you come face-to-face with … another face. Not another diver, but a face made of stone! It is part of a statue, and it is covered in clumps of algae and crusty bits of coral. 


This is not the only statue you see. There are many here, all covered in and surrounded by sea life. What’s going on here?


You dove into the middle of MUSA, a 500sculpture underwater museum. This place is an artificial reef. It was created to protect some of Mexico’s natural reefs, which have been damaged by storms, boat anchors, and tourism. 

Bigeyes like these live near coral reefs.

The Value of Reefs

Our oceans cover 71 percent of Earth’s surface and hold 97 percent of the planet’s water. No matter where we live, we rely on our oceans for the air we breathe. Ocean plants produce half of the world’s oxygen, and ocean waters absorb almost one-third of human-caused carbon dioxide emissions. The oceans also regulate the weather and play a role in Earth’s water cycle.

Coral reefs are often called the rainforests of the ocean. They are the largest living structures on Earth and play a key role in keeping our oceans healthy. Reefs also protect shorelines from storm surges and high tides.


Reefs provide food, shelter, protection, and spawning areas for thousands of species of fish and other marine organisms. Reefs are study areas for scientists, such as those who study climate change. Reefs may hold the key to new types of medicine, too. Compounds taken from coral reef species have already been used to treat many infections and diseases. And millions of people worldwide count on coral reefs every day to provide some food or income from fishing.

This natural reef in the Red Sea is full of marine life. 

Reefs in Trouble

Unfortunately, increased human pressures are putting a tremendous strain on the health of our oceans and reef systems. Threats include fishing methods that damage reefs, careless tourism, pollution, and climate change.


Here in Cancún, Mexico, the tourism industry was bringing more than 400,000 people to the natural reefs every year. Many of them were beginning divers who typically caused more damage to the reefs than experienced divers.

This reef was damaged by people blast fishing with dynamite.

Mexico’s National Marine Park created the underwater museum, MUSA, in an attempt to draw people away from natural reefs and toward artificial ones instead. It’s working. Forty percent of the people who would have visited the natural reefs now visit MUSA, including 95 percent of the beginners. That’s a lot less wear and tear on natural reefs. When natural reefs are in trouble, there are things we can do!