Juergen Freund / Moral eels, Urchins, Cuttlefish, Shrimp and other marine life living within a discarded tyre and fishing net under a ships' harbour, Maluku, Indonesia. November.

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.

Juergen Freund / Bleached Staghorn corals (Acropora cervicornis), Great Barrier Reef, Australia, 2017.

Juergen Freund / Timelapse of Giant sea cucumbers (Thelenota ananas) moving underwater, with a Giant clam (Tridacna gigas) in the background, Great Barrier Reef, Queensland, Australia, 2015.

Tim Fitzharris / Parrotfish (Scaridae), Wrasse (Labridae), and Sergeant Major Damselfish (Abudefduf saxatilis) school, Balicasag Island, Philippines

David Fleetham / Green sea turtles (Chelonia mydas) on corals, Hawaii.

David Fleetham / Fire Dartfish / Fire Goby (Nemateleotris magnifica) against colourful coral. Fiji's outer reef.

David Fleetham / Guineafowl pufferfish (Arothron meleagris) puffed up in defence, Hawaii.

Alex Mustard / Bengal snapper (Lutjanus bengalensis), Bannerfish (Heniochus diphreutes) and Fusiliers (Caesio sp.) diving towards coral reef to avoid predators. North Ari Atoll, Maldives. Indian Ocean.

Jordi Chias / Woman snorkeller swimming inside lagoon Toau atoll, Tuamotu Archipelago, French Polynesia, Pacific Ocean.

Jordi Chias / Goliath grouper (Epinephelus itajara) inside a coral cave. Bloody Bay Wall, Little Cayman, Cayman Islands. British West Indies. Caribbean Sea.

Jordi Chias / Schoolmaster snapper (Lutjanus apodus) school in the reef, Little Cayman island, Cayman Islands, Caribbean.