Doug Perrine / Bioluminescence from glowing plankton in sea tide line on beach, with stars above and ship lights on horizon, Vaadhoo Island, Raa Atoll, Maldives, Indian Ocean, October 2010

Franco Banfi / Tail of Blue whale diving (Balaenoptera musculus brevicauda) possibly the pygmy sub-species of blue whale, (Balaenoptera musculus). Mirissa, Sri Lanka, Indian Ocean. Photo taken under permit

Franco Banfi / Tail of Blue whale (Balaenoptera musculus brevicauda). This may be the pygmy sub-species of blue whale, Balaenoptera musculus. Mirissa, Sri Lanka, Indian Ocean

Shane Gross / Sperm whale (Physeter macrocephalus) mother and calf, Sri Lanka. March.

Shane Gross / Flying fish (Exocoetidae) caught and drowned in a drift net off the coast of Sri Lanka.

Tui De Roy / Strawberry land hermit crab (Coenobita perlatus). On white coral sand beach, Small unhinhabited coral islet in Raa Atoll lagoon, Maldives

Fred Olivier / Tawny hermit crab (Coenobita rugosus) emerging from its shell, Christmas Island, Indian Ocean, Australian Territory.

Alex Mustard / Jellyfish (Catostylus sp.) swimming in a slick of plastic debris. Turtles feed on jellies such as these and this photo shows how easily they can get confused and feed on plastic instead. Indian Ocean...

Alex Mustard / RF - Portrait of Coral hermit crab (Paguritta harmsi) living in a hard coral colony. North Male Atoll, Maldives. Indian Ocean (This image may be licensed either as rights managed or royalty free.)

Alex Mustard / RF - A school of Crescent-tail bigeye (Priacanthus hamrur) on a coral reef. North Male Atoll, Maldives. Indian Ocean (This image may be licensed either as rights managed or royalty free.)

Alex Mustard / RF - Blue whale (Balaenoptera musculus) diving vertically down into the ocean to feed. Indian Ocean, off Sri Lanka. (This image may be licensed either as rights managed or royalty free.)

Alex Mustard / Blue whale (Balaenoptera musculus) swimming beneath the surface of the ocean. Indian Ocean, off Sri Lanka.

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

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

Alex Mustard / Jellyfish (Catostylus sp.) swims beneath a slick of plastic debris. Indian Ocean off Sri Lanka. Highly commended in the Environmental Report section, Montphoto competition 2019

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 / School of White collar butterflyfish (Chaetodon collare) pack together above a coral reef. North Male Atoll, Maldives. Indian Ocean

Tony Wu / Sperm whale (Physeter macrocephalus), ten swimming together in gathering of more than 50 individuals. Whales with flatulence and defecating. Sri Lanka.

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

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.

Tony Wu / Blue whale (Balaenoptera musculus indica) in Indian Ocean, Mirissa, Matara, Sri Lanka.

Alex Mustard / Blue whale (Balaenoptera musculus) diving beneath the surface. Indian Ocean, Sri Lanka.

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.

Alex Mustard / Oriental sweetlips (Plectorhinchus vittatus) pair. South Ari Atoll, Madlives. Indian Ocean.

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

Alex Mustard / RF - Bannerfish (Heniochus diphreutes) schooling in coral reef. Long exposure. North Male Atoll, Maldives. Indian Ocean. (This image may be licensed either as rights managed or royalty free.)

Franco Banfi / Bryde's whale (Balaenoptera edeni) Trincomalee, Eastern Province, Sri Lanka, Bay of Bengal, Indian Ocean

Franco Banfi / Bryde's whale (Balaenoptera edeni) tail, Trincomalee, Eastern Province, Sri Lanka, Bay of Bengal, Indian Ocean

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

Jordi Chias / Spotted eagle ray (Aetobatus narinari) school, Kagi kandhu, ;North Male Atoll, Maldives, Indian Ocean.

Jordi Chias / Blue spotted trevally (Caranx bucculentus) hunting small fish in the reef, South Ari Atoll, Maldives, Indian Ocean.

Jordi Chias / Round ribbontail ray (Taeniura meyeni) South Ari Atoll, Maldives. Indian Ocean.

Jordi Chias / Oriental sweetlips (Plectorhinchus vittatus) South Ari Atoll, Maldives, Indian Ocean.

Jordi Chias / Hawksbill turtle (Eretmochelys imbricata) feeding on coral, South Ari Atoll, Maldives Islands, Indian ocean.

Alex Mustard / Wave breaking over the rubble zone close to the reef crest of a coral reef. Baa Atoll, Maldives. Indian Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae) juvenile male. This is the first verified record of a living humpback whale in the waters off Sri Lanka.

Tony Wu / Humpback whale (Megaptera novaeangliae) juvenile male playing and spinning This is the first verified record of a living humpback whale in the waters off Sri Lanka.

Tony Wu / Juvenile Australian sea lion (Neophoca cinerea) silhouetted against blue skies at Carnac Island, Western Australia

Tony Wu / Juvenile Australian sea lion (Neophoca cinerea) resting in shallows, possibly to thermoregulate, Carnac Island, Western Australia.

Tony Wu / Pygmy blue whale (Balaenoptera musculus brevicauda) swimming in blue water, Sri Lanka, Indian Ocean.

Tony Wu / Pygmy blue whale (Balaenoptera musculus brevicauda) diving with pelagic fish (likely yellowfin tuna or similar open ocean predatory species) visible in the background, Sri Lanka, Indian Ocean.

Tony Wu / Blue whale (Balaenoptera musculus) swimming in s motion, Sri Lanka, Indian Ocean.

Tony Wu / Pygmy blue whale (Balaenoptera musculus brevicauda) close-up view of tail fluke, Sri Lanka, Indian Ocean.

Tony Wu / Sperm whales (Physeter macrocephalus) large group gathering together, rubbing together to shed skin, interacting and defecating. Indian Ocean, March.

Tony Wu / Sperm whale (Physeter macrocephalus) adult female swimming upwards to surface with other behind. Indian Ocean, March.