Andy Rouse / Galapagos green turtle (Chelonia mydas agassisi) underwater portrait, being inquisitive, note algae growing on head and shell

Tony Wu / Humphead parrotfish (Bolbometopon muricatum) shoal spawning in early morning, part of mass aggregation of thousands of fish. Caroline Islands, Palau.

Tony Wu / Humpback whale (Megaptera novaeangliae australis) female with suckling calf. Vava'u Islands, Tonga.

Tony Wu / Humpback whale (Megaptera novaeangliae australis) male calf playing at ocean surface after coming up to breathe. Vava'u Islands, Tonga.

Pascal Kobeh / False clown anemonefish (Amphiprion ocellaris) in a magnificent sea anemone (Heteractis magnifica), Sulu sea, Philippines

Tony Wu / Humpback whale (Megaptera novaeangliae) lying on its side while executing a series of pectoral fin slaps on ocean surface. Vava'u, Tonga, South Pacific.

Tony Wu / Humpback whale (Megaptera novaeangliae australis) female breaching. Vava'u, Tonga. Pacific Ocean.

Tony Wu / Humpback whale calf (Megaptera novaeangliae australis) female nudging her mother's mammary gland whilst trying to feed. Vava;u, Tonga, South Pacific.

Alex Mustard / Split level image of Leather corals (Sarcophyton sp.) flourishing in shallow water close to uninhabited coral islands. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean...

Alex Mustard / Commensal emperor shrimp (Periclimenes imperator) moves across the colourful red patterned surface of its host Candycane sea cucumber (Thelenota rubralineata). Misool, Raja Ampat, West Papua, Indonesi...

Alex Mustard / Three Pink anemonefish (Amphiprion perideraion) living in a purple skirted magnificent sea anemone (Heteractis magnifica) on a coral reef, below a small island. Misool, Raja Ampat, West Papua, Indones...

Alex Mustard / Orange painted frogfish (Antennarius pictus) fishing. Here the frogfish is illuminated by a snooted strobe and the background sand lit with a red LED torch. Bitung, North Sulawesi, Indonesia. Lembeh S...

Alex Mustard / Free swimming mimic octopus (Thaumoctopus mimicus). Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Free swimming mimic octopus (Thaumoctopus mimicus). Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Thorny seahorse (Hippocampus histrix) gripping onto a sponge. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Pair of Western clown anemonefish (Amphiprion ocellaris) spawning orange eggs on the rock beneath their Magnificent sea anemone (Heteractis magnifica) home on a coral reef. This photo shows the larger...

Alex Mustard / Two female Common seahorses (Hippocampus kuda) fighting over territory on the seabed. The brief fight was preceeded by a ritualised, synchronised parade. Bitung, North Sulawesi, Indonesia. Lembeh Stra...

Alex Mustard / Common seahorse (Hippocampus kuda) female wrapping her prehensile tail around piece of wood on the seabed. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Veined octopus (Amphioctopus marginatus) shelters inside an old clam shell, with silver-sides in the water above. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Whitemargin stargazer (Uranoscopus sulphureus) sets an ambush in the sand at night. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Veined octopus (Amphioctopus marginatus) emerging from its home in an old clam shell. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Reef lizardifsh (Synodus variegatus) at a cleaning station, being cleaned by Holthuis anemone shrimps (Ancylomenes holthuisi). Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Tony Wu / Blacktip reef shark (Carcharhinus melanopterus) beaching itself to catch sardines. Tonga South Pacific.

Tony Wu / Sardines (Clupeidae) fleeing from predators in the early morning. They were being herded and chased by Trevallies and Blacktip reef sharks in the water, and picked off by brown boobies and terns from...

Alex Mustard / Shoal of three Bigfin reef squid (Sepioteuthis lessoniana) in open water at night. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Portrait of a Giant frogfish (Antennarius commersoni) on a large Yellow elephant ear sponge (Ianthella basta). Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Coral (Lobophytum sp.) on a reef flat, with Hawksbill turtle (Eretmochelys imbricata) in background. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean.

Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) unusually feeding on hard coral polyps. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean.

Alex Mustard / Blacktip reef shark (Carcharhinus melanopterus) swims through schools of fish. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean.

Alex Mustard / Green turtle (Chelonia mydas) descending after breathing at the surface. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean.

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.

David Fleetham / Clark's anemonefish (Amphiprion clarkii), pair tending to egg mass placed beside the protection of an anemone. Yap, Micronesia.

David Fleetham / Blacktip reef shark (Carcharhinus melanopterus) swimming just below surface at sunset, split level view. Off the island of Yap, Micronesia.

Tony Wu / Humpback whale (Megaptera novaeangliae australis) female, stationary with calf heading to surface for breath of air. Vava'u, Tonga, South Pacific.

David Fleetham / Cleaner wrasse (Labroides dimidiatus) swimming alongside Golden damsel (Amblyglyphidodon aureus) looking for parasites, Fiji, Pacific Ocean.

David Fleetham / White-eyed moray eel (Muraena thyrsoides) close to Zebra lionfish (Dendrochirus zebra), Philippines.

David Fleetham / Crinoid shrimp (Periclimenes amboinensis) on matching Feather star (Comanthus bennetti) Philippines.

David Fleetham / Pair of White-eyed moray eels (Muraena thyrsoides) share the hole of a mooring block off Bali, Indonesia.

David Fleetham / Pixy hawkfish (Cirrhitichthys oxycephalus) in area of rich coral growth. Bali, Indonesia.

Alex Mustard / Tawny nurse shark (Nebrius ferrugineus) group, individuals circling each other at dusk. Vavuu Atoll, Maldives. Indian Ocean.

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

Franco Banfi / Three False clownfish (Amphiprion ocellaris) in Sea anemone (Heteractis magnifica) Lighthouse Reef, Cabilao Island, Bohol, Central Visayas, Philippines, Pacific Ocean.

Bert Willaert / School of Longfin spadefish (Platax teira), Kimbe Bay, West New Britain, Papua New Guinea

Ingo Arndt / Aerial view of Hardy Reef, Great Barrier Reef, Queensland, Australia, December 2010.

Ingo Arndt / Aerial view of Hardy Reef, Great Barrier Reef, Queensland, Australia, December 2010.

Tony Wu / Humpback whales (Megaptera novaeangliae) male during a competetive heat run. Vava'u, Tonga, South Pacific.

Tony Wu / Humpback whale (Megaptera novaeangliae) adult female at rest. The tubercles on the whale's head are clearly visible, as are the barnacles (Coronula diadema), whale lice (Cyamus boopis), and hairs on t...

Tony Wu / Humpback whale (Megaptera novaeangliae) female breaching together with her male calf. The calf had a large wound on his left peduncle area, one that appeared to be the result of a large bite, Vava'u,...

Tony Wu / Humpback whale (Megaptera novaeangliae) executing a dramatic tail slap, throwing up a cascade of water with its powerful fluke, Vava'u, Tonga, South Pacific

Tony Wu / Humpback whales (Megaptera novaeangliae) unusual scene with two adults tail-slapping together in rough seas, Vava'u, Tonga, South Pacific

Tony Wu / Humpback whale (Megaptera novaeangliae) male breaching in front of Hunga island in Vava'u, Tonga, South Pacific

Tony Wu / Humpback whale (Megaptera novaeangliae) male with his penis extended. Vava'u, Tonga. South Pacific.

Tony Wu / Humpback whale (Megaptera novaeangliae) calf 'Tahafa' male with injured pectoral fin and scarred body, with mother. Vava'u, Tonga, Pacific Ocean. COP26 Countdown Photo Competition 2021 Finalist.

Tony Wu / Humpback whale (Megaptera novaeangliae) male calf with his mother. Vava'u, Tonga. South Pacific.

Tony Wu / Humpback whales (Megaptera novaeangliae) in a heat run, with six males competing for the attention of a female that already has a calf. Vava'u, Kingdom of Tonga

Tony Wu / Humpback whale (Megaptera novaeangliae) rear view, taken while the whale was staying still and singing. Hunga Channel. Vava'u, Kingdom of Tonga, Pacific Ocean.

Tony Wu / Humpback whale (Megaptera novaengliae) young male twirling and playing in the water, Vava'u, Tonga, Pacific Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae) males tail fluke, Vava'u, Tonga, Pacific Ocean.

Tony Wu / Humpback whales (Megaptera novaeangliae) engaged in courtship, with the male hovering above the female. Vava'u, Tonga, Pacific Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae), fluke of female with male calf playing below, Vava'u, Tonga, Pacific Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae) calf nuzzling its mother, Vava'u, Kingdom of Tonga, Pacific Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae) and her calf pursued by males during heat run. Vava'u, Tonga, Pacific Ocean.

Tony Wu / Humpback whale calf (Megaptera novaeangliae) resting under the chin of its mother. Vava'u, Tonga, Pacific Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae) male calf with his resting mother. Vava'u, Kingdom of Tonga. Pacific Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae) female with calf, pursued by males during heat run. Vava'u, Kingdom of Tonga. Pacific Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae) male resting, Vava'u, Kingdom of Tonga. Pacific Ocean.

Alex Mustard / Western clownfish (Amphiprion oceallaris) in a Magnificent sea anemone (Heteractis magnifica). Yillet Kecil, MIsool, Raja Ampat, West Papua, Indonesia. Ceram Sea

Alex Mustard / Red and black anemonefish (Amphiprion melanopus) in a Bulb tentacle sea anemone (Entacmaea quadricolor). Kri Island, Raja Ampat, West Papua, Indonesia, South East Asia. Dampier Strait, Tropical West P...

Alex Mustard / Aggregation of Golden jellyfish (Mastigias sp.) in a marine lake in Palau, the golden colour of this species comes from symbiotic algae in its tissues. Jellyfish Lake, Eil Malk island, Rock Islands, P...

Alex Mustard / Green sea turtle (Chelonia mydas) female resting on a coral reef. Rock Islands, Palau, Mirconesia. Tropical west Pacific Ocean

Pete Oxford / Whale Shark (Rhincodon typus) feeding at Bagan (floating fishing platform), Cenderawasih Bay, West Papua, Indonesia. Winner of the Man and Nature Portfolio Award in the Terre Sauvage Nature Images Aw...

Pete Oxford / Whale Shark (Rhincodon typus) and Golden trevally (Gnathanodon speciosus) Cenderawasih Bay, West Papua, Indonesia.

Pete Oxford / Whale Shark (Rhincodon typus) with scuba diver, Cenderawasih Bay, West Papua, Indonesia.

Pete Oxford / Whale shark (Rhincodon typus) front view portrait, Cenderawasih Bay, West Papua. Indonesia.

Pete Oxford / Whale Shark (Rhincodon typus) close up of spotted skin, with Golden trevally (Gnathanodon speciosus) Cenderawasih Bay, West Papua, Indonesia.

Pete Oxford / Whale shark (Rhincodon typus) and scuba divers seen from below, Cenderawasih Bay, West Papua. Indonesia.

Pete Oxford / Whale shark (Rhincodon typus) and scuba divers seen from below, Cenderawasih Bay, West Papua. Indonesia. Winner of the Man and Nature Portfolio Award in the Terre Sauvage Nature Images Awards Competit...

Pete Oxford / Whale shark (Rhincodon typus) Cenderawasih Bay, West Papua. Indonesia.

Roy Mangersnes / Marine iguana (Amblyrhynchus cristatus) feeding in deep water to find algae, off the coast of Fernandina island on Galapagos. April 2016. Much of the algae on coast and at shallower depths have been k...

Roy Mangersnes / Marine iguana (Amblyrhynchus cristatus) feeding in deep water to find algae, off the coast of Fernandina island on Galapagos. April 2016. Much of the algae on coast and at shallower depths have been k...

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.

Alex Mustard / Colourful reef scene with Leather corals (Sarcophyton sp.), Soft corals (Dendronephthya sp.) Seafans (Melithea sp.) and fish, including Magenta slender anthias (Luzonichthys waitei) and Scalefin anthi...

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.

Franco Banfi / Pacific seahorse (Hippocampus ingens) Galapagos Islands, East Pacific Ocean

Franco Banfi / Marine iguanas (Amblyrhynchus cristatus) basking on volcanic rock, Punta Espinosa, Fernandina Island, Galapagos Islands, East Pacific Ocean.

Ben Hall / Marine iguana (Amblyrhynchus cristatus) on rock taken with slow shutter speed to show motion in the water, Galapagos islands, May.

Ben Hall / Galapagos sea lion (Zalophus wollebaeki) mother and young touching noses, Galapagos Islands, May

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 / Schooling silversides (Atheriniformes) split level with karst limestone cliff and West Papuan fishermen in their dugout outrigger canoe. Raja Ampat, Indonesia. Second Place in the Portfolio Award of t...

Juergen Freund / Whale shark (Rhincodon typus) split level view, Cenderawasih Bay, West Papua, Indonesia. Second Place in the Portfolio Award of the Terre Sauvage Nature Images Awards Competition 2015.

Alex Mustard / Portrait of a Severn's pygmy seahorse (Hippocampus severnsi) at Mioskon Island, Raja Ampat, West Papua, Indonesia. Dampier Strait. Tropical West Pacific Ocean.

Alex Mustard / Nudibranch (Nembrotha cristata) climbing on a Tunicate (Polycarpa aurata) at night. This species of seaslug feeds on seasquirts. A tiny cyclopoid copepod swimming past. Yillet Yecil, Yillet Islands, M...

Alex Mustard / Portrait of Bigfin squid (Sepioteuthis lessoniana) hovering in open water above a coral reef at night. Dampier Strait, Raja Ampat, West Papua, Indonesia. Tropical West Pacific Ocean