Duncan Murrell / Coral formations at low tide in Prony Bay in the Southern Lagoon, Lagoons of New Caledonia: Reef Diversity and Associated Ecosystems UNESCO World Heritage Site. New Caledonia.

Claudio Contreras / Aerial view of Red mangrove (Rhizophora mangle) coastal lagoon, Sian Ka'an Biosphere Reserve, Caribbean Sea, Mexico, January

Claudio Contreras / Aerial view of Contoy island from the north, Contoy Island National Park, Mesoamerican Reef System, near Cancun, Caribbean Sea, Mexico, January

Juergen Freund / Gorgonian fan coral (Gorgonaceae) in the shallow mangroves, split level. North Raja Ampat, West Papua, Indonesia. Second Place in the Portfolio Award of the Terre Sauvage Nature Images Awards Competit...

Juergen Freund / Split level view of coral reef, Komodo National Park, Flores, Lesser Sunda Islands, Indonesia. Second Place in the Portfolio Award of the Terre Sauvage Nature Images Awards Competition 2015.

Richard Robinson / Featherstar (Crinoidea) on red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand.

Juergen Freund / Aerial view of Whitehaven Beach - a seven kilometre stretch of pure white sand, Coral Sea, Pacific Ocean, August 2011

Juergen Freund / Aerial view of Hardy Reef with float planes, Great Barrier Reef, Australia, August 2011

Juergen Freund / Aerial view of Hamilton Island sailing race, off the coast of Queensland, Australia, August 2011

Juergen Freund / Aerial view of Hamilton Island sailing race, off the coast of Queensland, Australia, August 2011

Floris van Breugel / Staghorn corals (Acropora) on the coast of tropical island Ofu, one of the Manu'a islands, American Samoa. 2012.

Juergen Freund / Baby green turtle (Chelonia mydas) hatchling in the shallows of the beach, swimming out to sea. Anano Island, Wakatobi, South Sulawesi, Indonesia, November

Duncan Murrell / Coral formations at low tide and Cook pine trees (Araucaria columnaris) on an island, Prony Bay, New Caledonia.

Duncan Murrell / Coral formations at low tide in Prony Bay in the Southern Lagoon, Lagoons of New Caledonia: Reef Diversity and Associated Ecosystems UNESCO World Heritage Site. New Caledonia.

Duncan Murrell / Coral formations at low tide in Prony Bay in the Southern Lagoon, Lagoons of New Caledonia: Reef Diversity and Associated Ecosystems UNESCO World Heritage Site. New Caledonia.

Chris Gomersall / Walkers on coral sand beach on the isle of Eriskay in the Western Isles, Scotland. July 2017.

David Fleetham / Beach and hotels along coastline, aerial image. Tumon Bay, Guam, Mariana Islands, Micronesia. September 2017.

David Fleetham / Slender spongegoby (Phyllogobius platycephalops) and two Crabs of different species on Sponge. Several parasites with egg cases on the side of the Goby. Philippines.

Juergen Freund / Aerial tracking shot looking down on Daintree Rainforest, flying towards the beach and the coral reef shallows, Wet Tropics World Heritage Area, North Queensland, Australia. 2017.

Juergen Freund / Aerial tracking shot looking down on Daintree Rainforest, flying towards the beach and the coral reef shallows, Wet Tropics World Heritage Area, North Queensland, Australia. 2017.

Tim Fitzharris / Butterflyfish (Chaetodon sp) group and male Horned Boxfish (Lactoria cornuta), Coral Coast, Australia

Tim Fitzharris / Australian Sea Lion (Neophoca cinerea) trio, Coral Coast, Australia

Ashley Cooper / Man pushing out boat in Funafuti Atoll, Tuvalu. March 2007. This area is low lying and very susceptable to sea level rise.

Ashley Cooper / Man in boat in Funafuti Atoll, Tuvalu. MArch 2007. This area is low lying and very susceptable to sea level rise.

Ashley Cooper / Funafuti Atoll, Tuvalu. These low lying islands are very susceptible to sea level rise, March 2007

Tony Wu / Discarded fuel container on a beach in tourist destination. Lizard Island, Great Barrier Reef, Queensland, Australia. July 2012.

Tony Wu / Discarded plastic rubbish on a beach in tourist destination. Lizard Island, Great Barrier Reef, Queensland, Australia. July 2012.

David Fleetham / Scott Blain lines up on a reef with his HD video camera in a Gates housing. Kona Coast, Hawaii. Model Released

Richard Robinson / Aerial view of Vuata Vatoa Reef looking towards Vatoa Island, also known as Turtle Island by Captain Cook, Lau Island Group, Fiji.

Jordi Chias / Potato cod (Epinephelus tukula) Pomene Coast, South Mozambique, Indian Ocean, South-East Coast.

Jordi Chias / Potato cod (Epinephelus tukula) with school Blueline snappers (Lutjanus kasmira) Tofo Coast, Mozambique, Indian Ocean. South-East Coast.

Oriol Alamany / Rocks on the shore of the lagoon coral reef, Lord Howe island, Lord Howe Island Group UNESCO Natural World Heritage Site, New South Wales, Australia, October 2012.

Oriol Alamany / The Lagoon coral reef, Lord Howe island, Lord Howe Island Group UNESCO Natural World Heritage Site, New South Wales, Australia, October 2012.

Doug Perrine / Aerial view of coral caye (a small island), with sailboat, inside southern Belize barrier reef, near Placencia. Belize Barrier Reef Reserve System, a UNESCO Natural World Heritage Site. Belize, Centra...

Doug Perrine / Aerial view of Laughing Bird Caye, a narrow sand caye, Laughing Bird Caye National Park, near Placencia. Belize Barrier Reef Reserve System UNESCO Natural World Heritage Site. Belize, Central America,...

Doug Perrine / Aerial view of Laughing Bird Caye, a narrow sand caye (small island), in Laughing Bird Caye National Park. Belize Barrier Reef Reserve System UNESCO Natural World Heritage Site. Central America. Carib...

Doug Perrine / Aerial view of Laughing Bird Caye, a narrow sand caye, Laughing Bird Caye National Park, southern Belize barrier reef. Belize Barrier Reef Reserve System UNESCO Natural World Heritage Site, Central Am...

Doug Perrine / Aerial view of southern Belize barrier reef, showing Gladden Spit and Silk Cayes Marine Reserve, off Placencia. UNESCO Natural World Heritage Site. Central America, Caribbean Sea.

Doug Perrine / Aerial view of southern Belize barrier reef, showing Gladden Spit and Silk Cayes Marine Reserve. UNESCO Natural World Heritage Site, Belize, Central America. Caribbean Sea.

Doug Perrine / Aerial view of southern Belize barrier reef, showing Gladden Spit, where there is a sharp bend in the reef, Gladden Spit and Silk Cayes Marine Reserve, off Placencia. Belize Barrier Reef Reserve Syste...

Doug Perrine / Aerial view of southern Belize barrier reef near Placencia, showing reef bend at Gladden Spit, Gladden Spit and Silk Cayes Marine Reserve. With two tour boats inside the reef, and three fishing boats...

Doug Perrine / Aerial view of southern Belize barrier reef, near Placencia. Belize Barrier Reef Reserve System, a UNESCO Natural World Heritage Site. Belize, Central America.

Doug Perrine / Aerial view of small sand and coral cayes and coral bommies inside southern Belize barrier reef in vicinity. Near Placencia, Belize Barrier Reef Reserve System UNESCO Natural World Heritage Site, Cent...

Doug Perrine / Aerial view of channel through southern Belize barrier reef, with house on small caye. Near Placencia, Belize Barrier Reef Reserve System UNESCO Natural World Heritage Site, Central America.

Doug Perrine / Aerial view of southern Belize barrier reef, showing Little Water Caye, site of the ranger station for Gladden Spit and Silk Cayes Marine Reserve, off Placencia. Belize Barrier Reef Reserve System UNE...

Doug Perrine / Aerial view of an inhabited coral cay inside the southern Belize barrier reef, off Placencia, Stann Creek District, Belize Barrier Reef Reserve System UNESCO Natural World Heritage Site, Belize, Centr...

Doug Perrine / Aerial view of the Silk Cayes, three sand and coral cays ( small islands ), and patch reefs, inside the southern Belize barrier reef. Gladden Spit and Silk Cayes Marine Reserve, Belize Barrier Reef Re...

Doug Perrine / Aerial view of southern Belize barrier reef, showing Gladden Spit, where there is a sharp bend in the reef, and showing spur and groove coral formations outside of the reef crest. Gladden Spit and Sil...

Jiri Lochman / Coral Bay, Ningaloo Coast UNESCO Natural World Heritage Site, Western Australia, Australia.

Jiri Lochman / Staghorn Corals (Acropora sp.) spawning at night, Ningaloo Reef, Ningaloo Marine Park, Ningaloo Coast UNESCO Natural World Heritage Site, Western Australia, Australia.

Alex Mustard / Elkhorn coral (Acropora palmata) uprooted and washed into the middle of the street during Hurricane Ivan. East End, Grand Cayman, Cayman Islands. British West Indies. Caribbean Sea.

Pascal Kobeh / Green moray (Gymnothorax funebris) out of its hole or burrow, Belize, Caribbean

Pascal Kobeh / Spanish hogfish (Bodianus rufus) is cleaning a Blue tang surgeonfish (Acanthurus coeruleus) Yucatan Peninsula, Mexico

Willem Kolvoort / Dimorphic Egret (Egretta dimorpha) on edge of Aldabra lagoon with coral 'mushrooms', Natural World Heritage Site, Aldabra 2006

Willem Kolvoort / Aldabra lagoon with coral 'mushrooms' and mangrove trees, Natural World Heritage Site, Aldabra 2006

Willem Kolvoort / Crab Plovers (Dromas ardeola) along shore of Aldabra lagoon with coral 'mushrooms' and mangrove roots, Natural World Heritage Site, Aldabra 2006

Willem Kolvoort / Aldabra lagoon with coral 'mushroom', Natural World Heritage Site, Aldabra 2005

Willem Kolvoort / Crab Plovers (Dromas ardeola) along shore of Aldabra lagoon with coral 'mushrooms' and mangrove roots, Natural World Heritage Site, Aldabra 2006,

Willem Kolvoort / Crab Plovers (Dromas ardeola) along shore of Aldabra lagoon with coral 'mushrooms' and mangrove roots, Natural World Heritage Site, Aldabra 2006,

Willem Kolvoort / Dimorphic Egret (Egretta dimorpha) on edge of Aldabra lagoon with coral 'mushrooms', Natural World Heritage Site, Aldabra 2006

Willem Kolvoort / Aldabra lagoon with coral 'mushrooms' and mangrove trees at low tide, Natural World Heritage Site, Aldabra 2006

Willem Kolvoort / Dimorphic Egret (Egretta dimorpha) and Crab plovers (Dromas ardeola) on edge of Aldabra lagoon with coral 'mushrooms', Natural World Heritage Site, Aldabra 2006

Willem Kolvoort / Dimorphic Egret (Egretta dimorpha) and Crab plovers (Dromas ardeola) on edge of Aldabra lagoon with coral 'mushrooms', Natural World Heritage Site, Aldabra 2006

Willem Kolvoort / Bras Deux Cedres is an inlet in the coral island Grand Terre. The inlet is connected to Aldabra lagoon and has some underwater caves, Natural World Heritage Site, Aldabra

Norbert Wu / Reef on coast, Isla Mujeres, Mexico

Claudio Contreras / Aerial view of coastal lagoon and barrier reef, Sian Ka'an Biosphere Reserve, Caribbean Sea, Mesoamerican Reef System, Mexico, January

Claudio Contreras / Aerial view of northern part of Contoy Island, Contoy Island National Park, Mesoamerican Reef System, near Cancun, Caribbean Sea, Mexico, January

Claudio Contreras / Aerial view of Red mangrove (Rhizophora mangle) forest, Contoy Island National Park, Mesoamerican Reef System, near Cancun, Caribbean Sea, Mexico, January

Claudio Contreras / Aerial view of Contoy Island from the south, Contoy Island National Park, Mesoamerican Reef System, near Cancun, Caribbean Sea, Mexico, January

Claudio Contreras / Aerial view of visitors center, Contoy Island National Park, Mesoamerican Reef System, near Cancun, Caribbean Sea, Mexico, January

Claudio Contreras / Aerial view of coast of the Caribbean Sea, Mesoamerican Reef System, Mexico, January

Claudio Contreras / Aerial view of coastal lagoon and barrier reef, Sian Ka'an Biosphere Reserve, Caribbean Sea, Mesoamerican Reef System, Mexico, January

Philippe Clement / Common Coral Weed / Coralweed (Corallina officinalis) washed ashore on beach, Normandy, France. September

Alex Mustard / Hard corals growing beneath trees in a mangrove forest. Yanggefo Island, Gam Island, Raja Ampat, West Papua, Indonesia.

Alex Mustard / Hard corals growing beneath trees in a mangrove forest. Yanggefo Island, Gam Island, Raja Ampat, West Papua, Indonesia.

Juergen Freund / Split level of a shallow coral reef and mangroves, Irian Jaya, Raja Ampat, West Papua, Indonesia.

Juergen Freund / Coral reef split level with mangroves. Raja Ampat, West Papua, Irian Jaya, Indonesia.

Frederique Olivier / Aerial View of Ningaloo Reef, near Tantabiddi, Exmouth, Western Australia. May 2014.

Frederique Olivier / Aerial View of Ningaloo Reef, near Tantabiddi, Exmouth, Western Australia. May 2014.

Frederique Olivier / Aerial View of Ningaloo Reef, near Tantabiddi, Exmouth, Western Australia. May 2014.

Pascal Kobeh / Split level view of 'Barnacle' artificial reef with scuba diver. Built in 1997 with a steel frame using mild electric currents to encourage coral growth. Ihuru Island in North Male Atoll, Maldives,...

Richard Robinson / Close up of a hydroid coral (Errina dendyi) in Dusky Sound, Fiordland National Park, New Zealand.

Richard Robinson / Hydroid coral (Errina dendyi) in Dusky Sound, Fiordland National Park, New Zealand.

Richard Robinson / Carpet shark (Cephaloscyllium isabellum) egg attached to Black Coral (Antipathella fiordensis) in Dusky Sound, Fiordland National Park, New Zealand. April. Cropped.

Richard Robinson / Dorid nudibranch (Aphelodoris luctuosa) on a red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / Starfish (Henricia sp) on a red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / Red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / Fiordland black coral (Antipathella fiordensis) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / Close up of soft coral (Alcyonium aurantiacum) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / Hydroid coral (Errina dendyi) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / Hydroid coral (Errina dendyi) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / Creeping soft coral (Clavularia novaezealandiae) polyps in Doubtful Sound, Fiordland National Park, New Zealand.

Richard Robinson / A solitary coral (Caryophyllia profunda) in Doubtful Sound, Fiordland National Park, New Zealand.

Richard Robinson / A solitary coral (Caryophyllia profunda) in Doubtful Sound, Fiordland National Park, New Zealand.

Richard Robinson / Soft coral (Alcyonium aurantiacum) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / A solitary coral (Caryophyllia profunda) polyp in Doubtful Sound, Fiordland National Park, New Zealand.