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 / California sea lion (Zalophus californianus) pups in an underwater cave. Los Islotes, La Paz, Baja California Sur, Mexico. Sea of Cortez, Gulf of California, East Pacific Ocean.

Alex Mustard / Whale shark (Rhincodon typus) close to the camera with a golden trevally fish (Gnathanodon speciosus) and outline of another whale shark behind , in the plankton-rich green waters of La Paz bay, Baja...

Alex Mustard / Tawny nurse sharks (Nebris ferrungineus) at night. Vavuu Atoll, Maldives. Indian Ocean

Alex Mustard / Midnight snapper (Macolor macularis) shelters in a cavern on a coral reef with white soft corals (Scleronephthya sp.) and solderfish. Vavuu Atoll, Maldives. Indian Ocean

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 / Whitemargin stargazer (Uranoscopus sulphureus) sets an ambush in the sand 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 / Blue whale (Balaenoptera musculus) swims beneath the surface of the ocean. Indian Ocean, off Sri Lanka.

Alex Mustard / Pod of False killer whales (Pseudorca crassidens) swimming beneath the surface of the ocean. Indian Ocean, off Sri Lanka.

Alex Mustard / Forster's hawkfish (Paracirrhites forsteri) on a coral reef. Jackson Reef, Tiran, Sinai, Egypt. Strait of Tiran, Gulf of Aqaba, Egypt.

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 / Carapace of a dead olive Ridley turtle (Lepidochelys olivacea) entangled in discarded fishing gear. Indian Ocean, off Sri Lanka.

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

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.

SCOTLAND: The Big Picture / Blue mussels (Mytilus edulis) with encrusting marine life, Sula Sgeir, Scotland. UK, July

SCOTLAND: The Big Picture / Orange jewel anemones (Corynactis viridis) Sula Sgeir, Scotland, UK, February.

SCOTLAND: The Big Picture / Curled octopus (Eledone cirrhosa) amongst a horse mussel bed (Modiolus modiolus) Shetland, Scotland, UK, August.

SCOTLAND: The Big Picture / Dead man's fingers (Alcyonium digitatum) on a rocky reef with view of the sky, Shetland, Scotland, UK, August.

SCOTLAND: The Big Picture / Northern gannets (Morus bassanus) diving for fish, split level shot, Shetland, Scotland, UK, July.

SCOTLAND: The Big Picture / Close up of a Long clawed squat lobster (Munida rugosa) in Loch Carron, January 2016.

SCOTLAND: The Big Picture / Close up of a colony of Jewel anemones (Corynactis viridis) Scotland, UK, October.

SCOTLAND: The Big Picture / Northern gannets (Morus bassanus) diving for fish, split level shot, Shetland, Scotland, UK, September.

SCOTLAND: The Big Picture / Maiden's salp (Thetys vagina) , west coast of Scotland, UK, July.

SCOTLAND: The Big Picture / Kelp forest (Laminaria digitata) with small fish, Shetland, Scotland, UK, July.

SCOTLAND: The Big Picture / Jellyfish (Pelagia noctiluca) amongst plankton , Shetland Isles, Scotland.

Alex Mustard / California sea lion (Zalophus californianus) uses a Panamic cushion star (Pentaceraster cumingi) as a toy. The sealions pick up the starfish and then drop them and chase after them as they sink. Los I...

Franco Banfi / Humboldt squid (Dosidicus gigas) at night off Loreto, Sea of Cortez, Baja California, Mexico, East Pacific Ocean.

Franco Banfi / Beak and tentacles of Humboldt squid (Dosidicus gigas) at night off Loreto, Sea of Cortez, Baja California, Mexico, East Pacific Ocean.

Alex Mustard / Bigfin squid (Sepioteuthis lessoniana) hovering in mid water at night. Anilao, Batangas, Luzon, Philippines. Verde Island Passages, Tropical West Pacific Ocean.

Alex Mustard / Portrait of False clown anemonefish (Amphiprion ocellaris) Anilao, Batangas, Luzon, Philippines. Verde Island Passages, Tropical West Pacific Ocean.

Alex Mustard / Great white shark (Carcharodon carcharias) portrait, Guadalupe Island, Mexico. Pacific Ocean.

Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) cruising along the drop off of a coral reef. Bloody Bay Wall, Little Cayman, Cayman Islands. Caribbean Sea. NB. Turtle has two identification tags in its fron...

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

Alex Mustard / Portrait of Sally lightfoot crab (Grapsus grapsus) on a beach. San Cristobal Island, Galapagos Islands, Ecuador. Tropical East Pacific Ocean.

Alex Mustard / Yellowbelly hamlets (Hypoplectrus aberrans) pair spawning at dusk (artifically backlit). Hamlets are hermaphroditic species. George Town, Grand Cayman, Cayman Islands. Caribbean Sea.

Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) male swimming in open water above a coral reef. Tank Rock, Fiabacet, Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea, Tropical West Pacific Ocean.

Alex Mustard / Saddleback anemonefish (Amphiprion polymnus) in anemone home, Anilao, Batangas, Luzon, Philippines. Verde Island Passages, Tropical West Pacific Ocean.

Alex Mustard / Common ghostgoby (Pleurosicya mossambica) with another fish in its mouth on soft coral (Dendronephthya sp.). Tulamben, Bali, Indonesia. Java Sea

Alex Mustard / Nurse shark (Ginglymostoma cirratum) young caught in a fishtrap. North Sound, Grand Cayman, Cayman Islands. Caribbean Sea.

Alex Mustard / Harlequin sweetlips (Plectorhinchus chaetodonoides) cleaned by a pair of bluestreak cleaner wrasse (Labroides dimidiatus). South Atoll, Tubbataha Atolls, Tubbataha Reefs Natural Park, Palawan, Philipp...

Alex Mustard / Spaghetti garden eels (Gorgasia maculata) stretching up out of their burrows on a rubble slope, with Mysiid shrimp swimming around their bodies near the seabed. Dumaguete, Dauin, Negros, Philippines....

Alex Mustard / Strawberry anemone (Utricina lofotensis) grows beneath Bull kelp forest (Nereocystis luetkeana). Browning Pass, Port Hardy, Vancouver Island, British Columbia. Canada. North East Pacific Ocean.

Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) on a reef wall with a rope sponge. East End, Grand Cayman, Cayman Islands. Caribbean Sea.

Alex Mustard / Diver exploring the wreck of HMS Scylla, which is colonized by Dead man's fingers (Alcyonium digitatum). Whitsands Bay, Cornwall, England. UK, July.

Alex Mustard / Napoleon wrasse (Cheilinus undulatus) super male, patrolling coral, Ras Mohammed Marine Park, Sinai, Egypt. Red Sea

Alex Mustard / Caribbean reef squid (Sepioteuthis sepioidea) amongst gorgonians, on a shallow coral reef. Cayman Brac, Cayman Islands. Caribbean Sea.

Alex Mustard / Group of predators hunting together, in an example of 'Nuclear foraging'. The Moray eel (Gymnothorax javanicus) flushes out prey, and is followed by a Napolean wrasse (Cheilinus undulatus) and a Bluef...

Alex Mustard / Large whip goby (Bryaninops amplus) with a parasitic copepod (with two trailing egg ribbons) perched on Red whip coral. Whale Rock. Fiabacet Islands, Misool, Raja Ampat, West Papua, Indonesia. Ceram S...

Alex Mustard / Tasseled wobbegong shark (Eucrossorhinus dasypogon) yawning. Citrus Ridge, Yanggefo Island, Gam Island, Raja Ampat, West Papua, Indonesia.

Alex Mustard / Colourful reef scene with Coral grouper (Cephalopholis miniata), map puffer (Arothron mappa) and Panda butterflyfish (Chaetodon adiergastos). Tank Reef, Fiabacet Islands, Misool, Raja Ampat, Indonesia...

Georgette Douwma / Crinoid (Crinoidea) on artificial reef. Mabul, Malaysia.

Pascal Kobeh / Female humpback whale (Megaptera novaeangliae) with its very young calf at the surface, Rurutu island, Australs Archipelago, French Polynesia. Pacific Ocean.

Alex Mustard / A long exposure renders Bar jacks (Carangoides ruber) as ghostly trails as they swim around a sponge, on a coral reef, at night. East End, Grand Cayman, Cayman Islands. Overall winner of GDT competiti...

Alex Mustard,Alex Mustard / A blue light fluorescence photo of Jewel anemones (Corynactis viridis). The blue light source excites the fluorescent pigments in the anemones, which emit light of other colours. The muddy seabed and...

Alex Mustard,Alex Mustard / A nudibranch (Dendronotus frondosus) photographed in the field aquarium, Gulen, Norway. North East Atlantic.

Alex Mustard,Alex Mustard / A portrait of a nudibranch ( Limacia clavigera) searching for food on algae. Gulen, Norway. North East Atlantic Ocean.

Alex Mustard,Alex Mustard / A signal blenny (Emblemaria hypacanthus) displays its showy dorsal fin as it extends out of its tube home. La Paz, Mexico. Sea Of Cortez, East Pacific Ocean.

Alex Mustard,Alex Mustard / A portrait of a small Candy stripe shrimp (Lebbeus grandimanus) in front of its host pink anemone (out of focus because of the magnification). Browning Wall, Browning Pass, Port Hardy, Vancouver Islan...

Alex Mustard,Alex Mustard / Green surf anemones (Anthopleura xanthogrammica) grow in shallow water below the temperate rain forest. Browning Pass, Port Hardy, Vancouver Island, British Columbia, Canada. North East Pacific Ocean.

Alex Mustard,Alex Mustard / Rainbow trout (Oncorhynchus mykiss) under trees, Capernwray Lake, Lake District, England, UK.

Alex Mustard,Alex Mustard / Whaleshark (Rhincodon typus) swimming and filtering fish eggs from the water. A behaviour known as ram-feeding. Isla Mujeres, Quintana Roo, Yucatan Peninsular, Mexico. Caribbean Sea.

Alex Mustard,Alex Mustard / Veined octopus (Amphioctopus marginatus) shelters in discarded coconut shell. Lembeh Strait, North Sulawesi, Indonesia. Molucca Sea.

Alex Mustard,Alex Mustard / A female (in front) and male Sockeye salmon (Oncorhynchus nerka) over eggs in their spawning river. Adams River, British Columbia, Canada, October.

SINCLAIR STAMMERS / Preserved Coelocanth (Latimeria chalumnae) on public display at the Natural History Museum in London, found originally off the Comoro Islands in the Indian Ocean. In life they are a dark blue colour w...

Alex Mustard / Spotted scorpionfish (Scorpaena plumieri) lying motionless and camouflaged in soft corals. West Palm Beach, Gulf Stream, West Atlantic Ocean, Florida, USA.

Chris Gomersall / 2020VISION / Passengers on observation deck of Sea Life Surveys vessel Sula Beag watching a Bottlenose dolphin (Tursiops truncatus) bow riding in the Sound of Mull, Inner Hebrides, Scotland, UK, July 2011. 2020VIS...

Michele Westmorland / Underwater Sculpture Gallery off Molinere Point, created by Jason de Caires Taylor. Colonised by sea life, Grenada, West-Indies, Caribbean, May 2009. No release.

Peter Cairns / 2020VISION / Group of tourists wearing waterproof clothing and life jackets photograph seabirds from zodiac boat on tour around Bass Rock, North Berwick, Firth of Forth, Lothian, Scotland, UK, August 2011

Peter Cairns / 2020VISION / Group of tourists wearing waterproof clothing and life jackets photograph Gannet colony from zodiac boat on tour around Bass Rock, North Berwick, Firth of Forth, Lothian, Scotland, UK, August 2011. Di...

Peter Cairns / 2020VISION / Group of tourists wearing waterproof clothing and life jackets in zodiac boat for seabird safari tour around Bass Rock, North Berwick, Firth of Forth, Lothian, Scotland, UK, August 2011

Alex Mustard / 2020VISION / View up through tidepool of 2020Vision young photographer, Bertie Gregory, Falmouth, Cornwall, UK, July 2011. Model released. Did you know? Life isnt easy in a rock pool! Animals here must deal with c...

Graham Eaton / Leatherback Turtle (Dermochelys coriacea) hatchling crossing a beach to get to the sea. Cayenne, French Guiana, July.

Juergen Freund / Split level image of shallow bleaching corals at sunset, New Ireland, Papua New Guinea

Juergen Freund / View of sea surface through a Whip coral forest (Junceella sp) Kimbe Bay, West New Britain, Papua New Guinea

Juergen Freund / Sea pen octocoral (Veretillum sp) with polyps out, feeding, Misool, Raja Ampat, West Papua, Indonesia

Juergen Freund / Hard brain coral (Platygyra sp) half covered with a pink algae, Moluccas Islands, Indo-pacific

Juergen Freund / Split level of shallow bleaching corals and island, New Ireland, Papua New Guinea, June 2010

Juergen Freund / Umbrella and other human waste thrown out into the coastal waters, settling on the ground becoming marine life habitat, Moluccas Islands, Indonesia, December 2009

Juergen Freund / Pygmy seahorse (Hippocampus bargibanti) camouflaged on coral (Muricela sp). Lembeh Strait, North Sulawesi, Indonesia

Juergen Freund / Leatherback turtle (Dermochelys coriacea) baby speeding towards the sea. Warmamedi beach, Bird's Head Peninsula, West Papua, Indonesia, July 2009

Juergen Freund / Newly hatched Leatherback turtle (Dermochelys coriacea) babies moving from the nest towards the sea. Warmamedi beach, Bird's Head Peninsula, West Papua, Indonesia, July 2009