A colorful set of gorgonians, reef-building corals, and other invertebrates grow on a diverse reef in the Caribbean Sea.

A beautiful coral reef, dominated by colorful gorgonians, grows along the edge of the Blue Hole in Lighthouse Reef in the Caribbean Sea. This reef is part of the massive Mesoamerican Reef System, the second largest barrier reef on Earth.

A beautiful coral reef, dominated by colorful gorgonians, grows along the edge of Turneffe Atoll in the Caribbean Sea. This reef is part of the massive Mesoamerican Reef System, the second largest barrier reef on Earth.

A large roughtail stingray, Dasyatis centroura, lays on the seagrass-covered seafloor of Turneffe Atoll off the coast of Belize. This reef is part of the massive Mesoamerican Reef System in the Caribbean Sea, the second largest barrier reef on Earth.

Horse-eye jacks (Caranx latus), schooling in Hol Chan Marine Preserve, inside the Mesoamerican Barrier Reef, Belize

Nurse sharks (Ginglymostoma cirratum), being fed in Hol Chan Marine Preserve, inside the Mesoamerican Barrier Reef, Belize

Nurse sharks (Ginglymostoma cirratum), being fed in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Nurse sharks (Ginglymostoma cirratum), being fed in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Nurse sharks (Ginglymostoma cirratum), being fed in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Nurse shark (Ginglymostoma cirratum), with boat in Hol Chan Marine Preserve, inside the Mesoamerican Barrier Reef, Belize

Nurse sharks (Ginglymostoma cirratum), massing in Hol Chan Marine Preserve, inside the Mesoamerican Barrier Reef, Belize

Southern stingray (Hypanus americanus), with snorkeler in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Southern stingray (Hypanus americanus) being fed in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Southern stingray (Hypanus americanus) buried in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Southern stingray (Hypanus americanus) over sand in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Southern stingray (Hypanus americanus) over sand in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Southern stingray (Hypanus americanus) over sand in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Southern stingray (Hypanus americanus) over sand in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Southern stingray (Hypanus americanus) over sand in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Tourists hand-feeding tarpon (Megalops atlaticus), at feeding station inside the Mesoamerican Barrier Reef, Belize

Tourists hand-feeding tarpon (Megalops atlaticus), at feeding station inside the Mesoamerican Barrier Reef, Belize

West Indian manatee (Trichechus manatus), on the sand near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

West Indian manatee (Trichechus manatus), with sharksucker, Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Spotted eagle ray (Aetobatus narinari), Hol Chan Marine Preserve, inside the Mesoamerican Barrier Reef, Belize

Tarpon (Megalops atlaticus), underwater at feeding station inside the Mesoamerican Barrier Reef, Belize

West Indian manatee (Trichechus manatus), with snorkelers near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

West Indian manatee (Trichechus manatus), with snorkeler near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

West Indian manatee (Trichechus manatus), with snorkeler near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

West Indian manatee (Trichechus manatus), with snorkeler near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Green sea turtle (Chelonia mydas), feeding on the sand near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Tourist hand-feeding magnificent frigatebird (Fregata magnificens), at feeding station, Mesoamerican Barrier Reef, Belize

Green sea turtle (Chelonia mydas), feeding on the sand near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Green sea turtle (Chelonia mydas), feeding on the sand near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Green sea turtle (Chelonia mydas), feeding on the sand near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Green sea turtle (Chelonia mydas), with snorkeler near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Green sea turtle (Chelonia mydas), surfacing for air near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Caribbean spiny lobster (Panulirus argus), underwater at Half Moon Caye, UNESCO, Mesoamerican Barrier Reef, Belize

Underwater view of of the reef system at Half Moon Caye, UNESCO, Mesoamerican Barrier Reef, Belize

A myriad of fish and coral underwater at Hol Chan Marine Preserve, inside the Mesoamerican Barrier Reef, Belize

A myriad of fish and coral underwater at Hol Chan Marine Preserve, inside the Mesoamerican Barrier Reef, Belize

Green sea turtle (Chelonia mydas), surfacing for air near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Green sea turtle (Chelonia mydas), with snorkeler near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Soft corals and sponges underwater on Long Caye in the Mesoamerican Barrier Reef, Belize

Brassy chubs (Kyphosus vaigiensis), being fed by boat operators inside the Mesoamerican Barrier Reef, Belize

Brassy chubs (Kyphosus vaigiensis), being fed by boat operators inside the Mesoamerican Barrier Reef, Belize

Adult dwarf minke whale (Balaenoptera acutorostrata), with snorkeler, Great Barrier Reef, Queensland, Australia, Pacific

A colorful set of gorgonians, reef-building corals, and other invertebrates grow on a diverse reef in the Caribbean Sea.

A well-camouflaged yellow stingray, Urobatis jamaicensis, swims over a shallow seagrass meadow growing within Turneffe Atoll's lagoon in the Caribbean Sea. This reef is part of the massive Mesoamerican Reef System, the second largest barrier reef on Earth

A colorful West Indian starfish, Oreaster reticulatus, crawls over a shallow, sandy seafloor in Turneffe Atoll in the Caribbean Sea. This reef is part of the massive Mesoamerican Reef System, the second largest barrier reef on Earth.

A colorful West Indian starfish, Oreaster reticulatus, crawls over a shallow, sandy seafloor in Turneffe Atoll in the Caribbean Sea. This reef is part of the massive Mesoamerican Reef System, the second largest barrier reef on Earth.

Tourists hand-feeding tarpon (Megalops atlaticus), at feeding station inside the Mesoamerican Barrier Reef, Belize

Adult dwarf minke whale (Balaenoptera acutorostrata), underwater near Ribbon 10 Reef, Great Barrier Reef, Queensland, Australia, Pacific

Adult dwarf minke whale (Balaenoptera acutorostrata) with snorkelers near Ribbon 10 Reef, Great Barrier Reef, Queensland, Australia, Pacific

A colorful set of gorgonians, reef-building corals, and other invertebrates grow on a diverse reef in the Caribbean Sea.

Adult dwarf minke whale (Balaenoptera acutorostrata), underwater with snorkeler near Ribbon 10 Reef, Great Barrier Reef, Queensland, Australia, Pacific

Adult female dwarf minke whale (Balaenoptera acutorostrata) underwater near Ribbon 10 Reef, Great Barrier Reef, Queensland, Australia, Pacific

Green Island, Great Barrier Reef, Cairns, Queensland, Australia, Pacific

Green Island, Great Barrier Reef, Cairns, Queensland, Australia, Pacific

Statue among palm trees of Dunk Island Resort, Great Barrier Reef, Mission Beach, Queensland, Australia, Pacific

Looking out from lounge of Dunk Island Resort into Pacific Ocean, Great Barrier Reef, at twilight, Mission Beach, Queensland, Australia, Pacific

Dunk Island beach with islands offshore, palm leaves, Great Barrier Reef, UNESCO World Heritage Site, Queensland, Australia, Pacific

People snorkelling on Outer Great Barrier Reef near Cairns, North Queensland, Australia, Pacific

People snorkelling on Outer Great Barrier Reef near Cairns, North Queensland, Australia, Pacific

Boat moored in Hamilton harbour, Whitsundays, off the Great Barrier reef, Queensland, Australia, Pacific

A boat moored on the beach on Green Island, Great Barrier Reef, Queensland, Australia, Pacific

Aerial view of Sand Cay, Great Barrier Reef, Queensland, Australia

Aerial view of Sand Cay, Great Barrier Reef, Queensland, Australia, Pacific

The Great Barrier Reef, UNESCO World Heritage Site, Cairns, Queensland, Australia, Pacific

Aerial view of Sand Cay, Great Barrier Reef, Queensland, Australia

The Great Barrier Reef, UNESCO World Heritage Site, Cairns, Queensland, Australia, Pacific

The Great Barrier Reef, UNESCO World Heritage Site, Cairns, Queensland, Australia, Pacific

The Great Barrier Reef, UNESCO World Heritage Site, Cairns, Queensland, Australia, Pacific

Coral on the Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

Tourists on a semi submersible, viewing the Great Barrier Reef off Cairns in Queensland, Australia, Pacific

Tourists snorkelling from a dive and snorkel platform anchored to the Great Barrier Reef off Cairns in Queensland, Australia, Pacific

Queen conch storage trap, Belize Barrier Reef, Caribbean

Liitter and mangrove roots, Belize Barrier Reef, Caribbean

English key, Belize barrier reef

coral key, Belize barrier reef

Tourists parasailing off Green Island on The Great Barrier Reef near Cairns in Queensland, Australia, Pacific

Person sitting in wooden chair watching sunset, Belize Barrier Reef, Caribbean (rr)

Giant clam amongst the soft coral on the Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

Coral on the Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

A Green turtle (Chelonia mydas) swimming over the Great Barrier Reef off Cairns, Queensland, Australia, Pacific

Dead and broken coral on the sea bed, Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

A coral atoll from the air, part of the Great Barrier Reef near Cairns, Queensland, Australia, Pacific

Coral on the Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

Atoll formation with barrier reef, Chuuk, Federated States of Micronesia, Caroline Islands, Micronesia, Pacific Ocean, Pacific

Coral on the Great Barrier Reef, off Cairns, Queensland, Australia, Pacific

Cairns in Northern Queensland, Australia, Pacific

Aerial view of Punta Allen Sian Ka'an Reserve, Yucatan Peninsula, Mexico. Red lagoon near Boca Paila Bridge. In the language of the Mayan peoples who once inhabited this region, Sian Ka'an means Origin of the Sky. Located on the east coast of the Yucatán peninsula, this biosphere reserve contains tropical forests, mangroves and marshes, as well as a large marine section intersected by a barrier reef. It provides a habitat for a remarkably rich flora and a fauna comprising more than 300 species of birds, as well as a large number of the region's characteristic terrestrial vertebrates, which cohabit in the diverse environment formed by its complex hydrological system. Along its roughly 120 kilometres of coastline, the property covers over 400,000 hectares of land ranging from sea level to only ten m.a.s.l. The property boasts diverse tropical forests, palm savannah, one of the most pristine wetlands in the region, lagoons, extensive mangrove stands, as well as sandy beaches and dunes. The 120,000 hectares of marine area protect a valuable part of the Mesoamerican Barrier Reef and seagrass beds in the shallow bays. The lush green of the forests and the many shades of blue of the lagoons and the Caribbean Sea under a wide sky offer fascinating visual impressions.

Aerial view of Punta Allen Sian Ka'an Reserve, Yucatan Peninsula, Mexico. Red lagoon near Boca Paila Bridge. In the language of the Mayan peoples who once inhabited this region, Sian Ka'an means Origin of the Sky. Located on the east coast of the Yucatán peninsula, this biosphere reserve contains tropical forests, mangroves and marshes, as well as a large marine section intersected by a barrier reef. It provides a habitat for a remarkably rich flora and a fauna comprising more than 300 species of birds, as well as a large number of the region's characteristic terrestrial vertebrates, which cohabit in the diverse environment formed by its complex hydrological system. Along its roughly 120 kilometres of coastline, the property covers over 400,000 hectares of land ranging from sea level to only ten m.a.s.l. The property boasts diverse tropical forests, palm savannah, one of the most pristine wetlands in the region, lagoons, extensive mangrove stands, as well as sandy beaches and dunes. The 120,000 hectares of marine area protect a valuable part of the Mesoamerican Barrier Reef and seagrass beds in the shallow bays. The lush green of the forests and the many shades of blue of the lagoons and the Caribbean Sea under a wide sky offer fascinating visual impressions.

Aerial view of Punta Allen Sian Ka'an Reserve, Yucatan Peninsula, Mexico. Red lagoon near Boca Paila Bridge. In the language of the Mayan peoples who once inhabited this region, Sian Ka'an means Origin of the Sky. Located on the east coast of the Yucatán peninsula, this biosphere reserve contains tropical forests, mangroves and marshes, as well as a large marine section intersected by a barrier reef. It provides a habitat for a remarkably rich flora and a fauna comprising more than 300 species of birds, as well as a large number of the region's characteristic terrestrial vertebrates, which cohabit in the diverse environment formed by its complex hydrological system. Along its roughly 120 kilometres of coastline, the property covers over 400,000 hectares of land ranging from sea level to only ten m.a.s.l. The property boasts diverse tropical forests, palm savannah, one of the most pristine wetlands in the region, lagoons, extensive mangrove stands, as well as sandy beaches and dunes. The 120,000 hectares of marine area protect a valuable part of the Mesoamerican Barrier Reef and seagrass beds in the shallow bays. The lush green of the forests and the many shades of blue of the lagoons and the Caribbean Sea under a wide sky offer fascinating visual impressions.

Snorkeling excursion in the shallow waters of the Bora Bora lagoon, Moorea, French Polynesia, Society Islands, South Pacific. Cook's Bay.

Moorea island french polynesia lagoon aerial view panorama. reef see, Moorea island (aerial view), Windward Islands, Society Islands, French Polynesia, Pacific Ocean. landscape

Snorkeling excursion in the shallow waters of the Bora Bora lagoon, Moorea, French Polynesia, Society Islands, South Pacific. Cook's Bay.

Snorkeling excursion in the shallow waters of the Bora Bora lagoon, Moorea, French Polynesia, Society Islands, South Pacific. Cook's Bay.

Typical houses, road, and reef see, Moorea island (aerial view), Windward Islands, Society Islands, French Polynesia, Pacific Ocean.

Pink anemonefish, Amphiprion perideraion, in sea anemone, Great barrier reef marine park, Australia (South Pacific).

Feather stars, Oxycomanthus bennetti, Temple of Doom, Great Barrier Reef, Australia (S. Pacific).