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

As you swim down, you see something near the seabed. You descend to nearly 10 meters (32 feet). There, you come face-to-face with … another face. A face made of stone! It is part of a statue covered in clumps of algae and corals.

This is not the only statue you see. There are many. What’s going on here? You dove into the middle of MUSA, a 500-sculpture underwater museum. This place is an artificial reef. It was created to protect some of Mexico’s natural reefs. Many 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. They hold 97 percent of the planet’s water. We rely on our oceans for the air we breathe. Ocean plants produce half of the world’s oxygen. Ocean waters absorb almost one-third of carbon dioxide emissions. The oceans also regulate the weather and play a crucial role in Earth’s water cycle.

Coral reefs are the largest living structures on Earth. They play a key role in keeping our oceans healthy. Reefs also protect shorelines from storms and high tides. Reefs provide food, shelter, and protection. They are spawning areas for fish and other marine organisms. They are study areas for scientists. And millions of people worldwide count on coral reefs every day for food or income from fishing.

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

Reefs in Trouble

Unfortunately, increased human activity is putting a strain on the health of our oceans and reefs. Threats include fishing methods that damage reefs. Careless tourism, pollution, and climate change threaten the reefs, too.

Here in Cancún, Mexico, more than 400,000 tourists visited the natural reefs every year. Many of them were beginning divers who caused more damage than experienced divers.

This reef was damaged by people blast fishing with dynamite.

Mexico’s National Marine Park created the underwater museum, MUSA, to draw people away from natural reefs and toward artificial ones instead. It’s working. Forty percent of the people who would have visited natural reefs now visit MUSA.