­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 water.

You swim down. You see something near the seabed. There, you come face-to-face with … another face. It is part of a stone statue covered in clumps of algae and bits of corals. There are many statues here. What’s going on? You dove into the middle of MUSA. It’s an underwater museum of sculptures. It’s also an artificial reef. It was created to protect some of Mexico’s natural reefs.

Bigeyes like these live near coral reefs.

The Value of Reefs

Oceans cover 71 percent of Earth’s surface. They hold 97 percent of the planet’s water. We depend on oceans for the air we breathe. Ocean plants produce half of the world’s oxygen. Ocean waters absorb carbon dioxide. The oceans also control the weather.

Coral reefs are the largest living structures on Earth. They play a big role in keeping our oceans healthy. Reefs also protect shorelines from storms and high tides.

Reefs provide food, protection, and spawning areas for fish and other marine life. And millions of people count on coral reefs for their food or income.

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

Reefs in Trouble

Unfortunately, increased human activity puts a strain on our oceans and reefs. Certain fishing methods damage reefs. Careless tourists, pollution, and climate change threaten the reefs, too.

This reef was damaged by people blast fishing with dynamite.

In Cancún, Mexico, more than 400,000 tourists visited the natural reefs every year. Many were beginning divers. Their lack of skill caused damage. MUSA was created to draw people away from natural reefs toward artificial ones. It’s working. Many people now visit MUSA instead of the natural reefs.