Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning mouth of Tomato Grouper (Cephalopholis sonnerati), Great Barrier Reef, Australia

Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning mouth of Tomato Grouper (Cephalopholis sonnerati), Great Barrier Reef, Australia

Doug Gimesy / Little blue penguin (Eudyptula minor), two standing on rocks at night, silhouetted against Melbourne city lights. St Kilda breakwater, Victoria, Australia. December 2016. COP26 Countdown Photo Competi...

Doug Gimesy / Little penguin (Eudyptula minor) on rocks of St Kilda breakwater, Melbourne city lights in background. Victoria, Australia. January 2017.

John Chan / California sea lion (Zalophus californianus) feeding on a Striped bass (Morone saxatilis), Southern California, USA.

Jordi Chias / Potato cod (Epinephelus tukula) Zavora Coast, Mozambique, Indian Ocean.

Tony Wu / Twinspot snapper (Lutjanus bohar) shoal rushing up to spawn, releasing a cloud of milky white sperm and eggs in the water column. Caroline Islands, Palau, November.

Tony Wu / Twinspot snapper (Lutjanus bohar) engaged in a mass spawning aggregation early in the morning. Caroline Islands, Palau. April. Winner of Underwater category, Wildlife Photographer of the Year 2016.

Alex Mustard / Portrait of pair of Bohar snappers (Lutjanus bohar) in their spawning aggregation. Shark Reef, Ras Mohammed Marine Park, Sinai, Egypt. Red Sea.

Alex Mustard / Portrait of Bohar snappers (Lutjanus bohar) in its spawning aggregation. Shark Reef, Ras Mohammed Marine Park, Sinai, Egypt. Red Sea.

Jiri Slama / Northern Gannet (Morus bassanus) pair in courting display, Bass Rock, Scotland, United Kingdom

Ben Hall / Northern gannets (Morus / Sula bassanus) portrait of individual with a courting pair in foreground, UK, Bass Rock, Scotland, Portrait category winner in the British Wildlife Photography Awards BWPA co...