The largest reef system in the world is of course the Great Barrier Reef in Australia, but the second largest is in the Caribbean. The Mesoamerican Barrier Reef System stretches along the coasts of Mexico, Belize, Guatemala, and Honduras and is a dazzling display of the rich diversity of life just below the waves.

Next time in Cancun or on the tropical beaches of Belize, take a scuba diving tour or snorkeling tour of this great underwater marvel. If one visits Australia, visit the Great Barrier Reef - one of the world's greatest treasures and is currently under threat from bleaching and other threats.

The Size And Ecosystem of The Mesoamerican Barrier Reef System

The Mesoamerican Reef is also called the Great Mayan Reef or Great Maya Reef. It extends for over 1,126 kilometers or 700 miles. in the Caribbean.

The reef system starts at the northern tip of the Yucatan Peninsula at Isla Contoy and goes south to the Bay Islands of Honduras. Much of it is protected in various national parts and protected areas like Cayos Cochinos Marine Park, Sian Ka'an biosphere reserve, Belize Barrier Reef, Arrecifes de Cozumel National Park, and others.

  • Length: 600-700 Miles Long
  • Great Barrier Reef: 1,429 Miles Long (Australia)

The reefs system is a tripartite world of mangroves, seagrass, and coral reefs. Due to its proximity to the shore, it is connected to the inshore habitats. The areas of mangroves, seagrass, and coral reef are bound so tightly by the tides, currents, and mutual dependency that they can't be teased apart.

  • Tripartite World: Of Mangroves, Seagrass, and Coral Reefs

One of the advantages the Mesoamerican Reef has over its Australian counterpart is its proximity to the shore. In places, the reef begins just within a few hundred yards of the shore and in other places, it extends to as much as 20 miles offshore. It is the home of a wide variety of reef types.

  • Begins: From A Few Hundred Yards to 20 Miles Off Shore

The reef system encompasses a rich mosaic of habitats spanning coast wetlands, lagoons, beaches and dunes, mangrove forests, seagrass beds, and (of course) coral reefs.

Along its sandy beaches one will find azure waters papers will fishing villages and an eye-watering beauty that draws thousands of holidaymakers every year to the likes of Cancun and Belize.

Related: A Shocking Comparison: 5 Photos Of The Great Barrier Reef 10 Years Ago & 5 Of It Today

Marine Wildlife and Threats

It is home to a plethora of marine life, here one will find over 500 species of fish, 60 coral species, 350 mollusk, and other marine mammals. One will see whales sharks congregate in northern areas around Isla Contoy. Whale sharks are normally solitary, but they come here in social groups to eat and to mate.

  • Fish: Over 500 Fish Species
  • Isla Contoy: Whale Sharks Congregate and Breed Around Isla Contoy

Some of the more notable residents of the reef include:

  • Crocodiles: The Saltwater Crocodile
  • Sea Turtles: Including the Green, Hawksbill, and Loggerhead Sea Turtles
  • Grouper: The Nassau and Goliath Groupers
  • Manatees: The Largest Population of Manatees in The Western Caribbean (Estimated Population of 1,000 to 1,500)
  • Whale Sharks: The Largest Aggregation of Whale Sharks Anywhere

Come here and enjoy some of the ocean's best seafood. Dine on fresh lobster, snapper, grouper, and conch.

Unfortunately, there are a number of threats that are damaging this fragile ecosystem and now much of it is stressed. Many of the threats are human-related like climate change, overfishing, agricultural runoff, and irresponsible tourism.

  • Lionfish: Invading Lionfish Are Damaging The System

Additionally, the reef system is suffering an invasion of red lionfish. These are native to the Indo-Pacific region and they severely damage the reef by eating nearly every reef tending species (like cleaner shrimp). Animals like cleaner shrimp keep the corals clean and disease-free.

Related: These Are The Best Places In The World To Dive With Manta Rays

Tours of The Mesoamerican Reef

There are many tours of this magnificent reef all along the coasts of the four countries it spans, here is an example of a snorkeling tour.

Small-Group Snorkeling in Puerto Morelos: This tour leaves from Puerto Morelos in Cancun, Mexico, and is a great way to skip the line for a snorkel tour of the Mesoamerican Barrier Reef. The groups are limited to 10 and are a great option for tourists with limited time. Here one will discover one of the world's most diverse marine environments. This tour is also great for families.

  • Gear: Includes All Snorkel Equipment, Wet Suits
  • Duration: 2 Hours - 2x 45 Minutes Snorkels
  • Included: Refreshments, Park Fees
  • Cost: From $45.00

Snorkeling is fun, but perhaps the best way to discover the reef is by scuba diving. Two companies offering scuba diving tours are Aquaworld and Scuba Diving Cancun.

For those who love diving wrecks, a paradise for wreck divers is Chuuk (Truk) Lagoon in Micronesia where one can see a whole sunken fleet.

Next: Want to Learn to Scuba Dive? Here Are The Best Places For Beginners To Take The Plunge