What makes the Mesoamerican Reef extraordinary

From a description of the work of the WWF in the Mesoamerian
Reef:

The jewel of the Caribbean Sea, the Mesoamerican Reef is a rich tapestry of fringing reefs, atolls,patch reefs, sea grass pastures and mangrove forests. An ancient natural system dating back 225 million years, it acts as a natural barrier against severe storms for Mexico, Guatemala, Belize and Honduras, and its presence is vital to the survival of many plants and animals as well
as humans.

As the most important barrier reef in the Western Hemisphere and the second largest in the world, the Mesoamerican Reef provides shelter for fascinating species, such as the mammoth whale shark and the endangered salt water crocodile. It is also home to one of
the world’s largest populations of manatees.

The place. A large mosaic of ecosystems, the Mesoamerican Reef covers nearly 115 million acres—from the northern end of the Yucatán Peninsula in Mexico and the Caribbean coasts of Belize and Guatemala, to the Bay Islands in northern Honduras. It includes ocean habitats, coastal zones, tropical and cloud forests, and watersheds that drain the Caribbean slope.

The species. The Mesoamerican Reef hosts more than 65 species of stony coral and more than 500 species of fish—including commercially-vital grouper, snapper and spiny lobster. It also provides refuge for sea turtles that feed and nest along the shoreline. Its watershed is home to jaguars, howler monkeys and birds such as the quetzal.

The people. More than two million people live in the coastal communities that span four countries. This population of great cultural and ethnic diversity depends on economic activities linked to coastal and marine resources, such as fishing and tourism. The region is also experiencing rapid population growth and increased exploitation of land and resources.