Alex Mustard / Shallow coral reef flat with corals (Pocillopora damicornis, Acropora humilis and Pocillopora verrucosa) in evening light. Gordon Reef, Strait of Tiran, Sinai, Egypt. Gulf of Aqaba, Red Sea.

Pascal Kobeh / Red spotted coral crab (Trapezia rufopunctata) hidden in a hard coral (Pocillopora sp.) New Caledonia, Pacific Ocean.

Alex Mustard / Hard corals (including Acropora sp., Platygyra sp. and Pocillopora spp.) growing in shallow water and reflected in the surface. Ras Umm Sid, Sharm El Sheikh, Sinai, Egypt. Red Sea

David Fleetham / Dwarf scorpionfish (Sebastapistes fowleri) in Cauliflower coral (Pocillopora meandrina). Kauai, Hawaii.

Alex Mustard / Hard coral (Pocillopora damicornis) spawning during the morning on a coral reef. The Alternatives, Sinai. Egypt. Red Sea

Alex Mustard / Hard coral (Pocillopora damicornis) spawning during the morning on a coral reef. The Alternatives, Sinai. Egypt. Red Sea

Doug Perrine / Bleached Antler coral (Pocillopora edouxi) at Lone Tree Arch, Kohanaiki, Kaloko, Kona, Hawaii Island, Hawaii, USA. Pacific Ocean.

Doug Perrine / Bleached Antler coral (Pocillopora edouxi) at Lone Tree Arch, Kohanaiki, Kaloko, Kona, Hawaii Island, Hawaii, USA. Pacific Ocean.

Doug Perrine / Bleached Antler coral (Pocillopora edouxi) with Arceye hawkfish (Paracirrhites arcatus) perched at bottom, Makako Bay, Keahole, Kona, Hawaii. Pacific Ocean.

Alex Mustard / A diver (Eleonora Manca) examines a coral propagation table with cuttings of (Stylophora sp) Aqaba, Jordan. Gulf of Aqaba, Red Sea. Model Released

Pascal Kobeh / Hard coral - on right, (Lobophyllia sp) bleached because of the raise of the water temperature, and on the left a dying needle coral (Seriatopora hystrix) covered with algae after a bleaching, Walindi...

Pascal Kobeh / Red spotted coral crab (Trapezia rufopunctata) hidden in a hard coral (Pocillopora ) Madagascar. Indian Ocean.

Alex Mustard / Colony of Cauliflower coral (Pocillopora damicornis) coral spawning gametes. Photographed one to two days before new moon. The Alternatives, Ras Mohammed Marine Park, Sinai, Egypt. Red Sea.

Solvin Zankl / Stony coral (Pocillopora sp) Raja Ampat, West Papua, Indonesia, Pacific Ocean.

Georgette Douwma / Coral (Stylophora subseriata) Egypt, Red Sea.

Ingo Arndt / Stony Coral (Pocillopora sp)

Fred Bavendam / Red-spotted Coral Crab (Trapezia rufopunctata) living among the stout branches of Cauliflower Coral (Pocillopora eydouxi), Bali, Indonesia

Gary Bell/ Oceanwide / Stony Coral (Pocillopora sp) bleaching, Solitary Islands Marine Park, New South Wales, Australia

Alex Mustard / Looking down at the top of a submerged reef covered in corals (Acropora spp. and Pocillopora sp.), Fathers Reef, Lolobau Island, Papua New Guinea. Bismark Sea, Pacific Ocean.

David Fleetham / Hawaiian lionfish (Dendrochirus barberi) resting in Antler coral (Pocillopora eydouxi), Hawaii, Pacific Ocean.

Doug Perrine / Blue-eye damselfish (Plectroglyphidodon johnstonianus) with Antler coral (Pocillopora meandrina) behind, in which it resides, Eel Cove, Kaiwi Point, Kona, Big Island, Hawaii, USA, Pacific Ocean.

Joel Sartore / Photo Ark / Catspaw coral (Stylophora pistillata) portrait, Omaha's Henry Doorly Zoo and Aquarium. Captive, occurs in Indo-Pacific.

Joel Sartore / Photo Ark / Catspaw coral (Stylophora pistillata) portrait, Omaha's Henry Doorly Zoo and Aquarium. Captive, occurs in Indo-Pacific.

Alex Mustard / Hard coral colony (Pocillopora sp.) on a coral reef with sunburst Tubbataha Atolls, Palawan, Philippines, Sulu Sea.

Alex Mustard / RF - Split level view of hard coral garden (including Acropora sp. and Pocillopora sp.) flourishing in shallow water around Misool Resort, Raja Ampat, West Papua, Ceram Sea, Pacific Ocean. (This image...

David Fleetham / Cauliflower coral (Pocillopora meandrina) spawning, releasing both eggs and sperm into open ocean just after sunrise, with a Multiband butterflyfish (Chaetodon multicinctus) feeding on the spawn, Hawa...

Doug Perrine / Two Big longnose butterflyfish (Forcipiger longirostris) hunting for prey hidden within the branches of an Antler coral (Pocillopora grandis), North Kona, Hawaii, Pacific Ocean.

David Fleetham / Spawning polyps of Cauliflower coral (Pocillopora meandrina), releasing eggs and sperm into open ocean just after sunrise, Hawaii, Pacific Ocean.

David Fleetham / Cauliflower coral (Pocillopora meandrina) spawning, releasing eggs and sperm into open ocean just after sunrise, with two Forcepsfish / Longnose butterflyfish (Forcipiger flavissimus) feeding on spaw...

Doug Perrine / Hawaiian whitespotted toby / White-spotted puffer (Canthigaster jactator) sheltering inside branches of Antler coral (Pocillopora grandis), North Kona, Hawaii, Pacific Ocean.

Doug Perrine / Hawaiian whitespotted toby / White-spotted puffer (Canthigaster jactator) sheltering inside branches of Antler coral (Pocillopora grandis), North Kona, Hawaii, Pacific Ocean.

Doug Perrine / Hawaiian dascyllus / Hawaiian threespot damsel (Dascyllus albisella) sheltering in and around the bleached branches of Antler coral (Pocillopora grandis), South Kona, Hawaii, Pacific Ocean.

David Fleetham / Antler coral ( Pocillopora eydouxi), spawning polyps, releasing both eggs and sperm into open ocean just after sunrise, Hawaii, Pacific Ocean.

David Fleetham / Colony of Antler coral (Pocillopora eydouxi), spawning, releasing both eggs and sperm into open ocean just after sunrise, Hawaii, Pacific Ocean.

Alex Mustard / Female Slingjaw wrasse (Epibulus insidiator) swimming over hard corals (Pavona sp.), (Porites sp.) and (Pocillopora sp.) in shallow water, Jackson Reef, Sinai, Egypt, Red Sea.

Alex Mustard / Hard coral (Pocillopora sp.), (Acropora sp.) and (Porites sp.) garden in shallow water, Jackson Reef, Sinai, Egypt, Red Sea.

Alex Mustard / Fluorescent coral (Pocillopora sp.) at night on a coral reef in blue light, with the lights from a resort jetty behind, Laamu Atoll, Maldives, Indian Ocean.

David Fleetham / Coral bleaching on a stand of Antler coral (Pocillopora eydouxi) caused by rising sea temperatures and climate change, Hawaii, Pacific Ocean, November, 2021.

Alex Mustard / Diverse hard coral growth (Pocillopora damicornis, Pocillopora verrucosa and Millepora dichotoma), flourishes beneath the barren desert cliffs in the Red Sea. Ras Katy, Sinai, Egypt. Gulf of Aqaba, Re...

Doug Perrine / Cauliflower coral (Pocillopora meandrina), bleached head surrounded by dead coral covered in algae. Honokeana Cove, Napili, West Maui, Hawaii, USA. October 2019.

Doug Perrine / Cauliflower coral (Pocillopora meandrina) colony bleached during a marine heat wave, coral fluorescing violet believed to be a protective response to reduce cell damage from sunlight. Surrounding reef...

Doug Perrine / Cauliflower coral (Pocillopora meandrina), bleached colonies and dead algae covered colonies during marine heatwave. Some corals fluorescing, believed to be a protective response to reduce cell damage...

Doug Perrine / Green sea turtle (Chelonia mydas) swimming over bleached Cauliflower coral (Pocillopora meandrina) colonies during marine heatwave. Black Rock, West Maui, Hawaii, USA. October 2019.

Doug Perrine / Antler coral (Pocillopora grandis), bleached due to symbiotic zooxanthellae algae being expelled because of environmental stress. Kohanaiki, North Kona Coast, Hawaii, USA. May 2020.

Doug Perrine / Antler coral (Pocillopora grandis), tips of branches. Bleached due to symbiotic zooxanthellae algae being expelled because of environmental stress. Kohanaiki, North Kona Coast, Hawaii, USA. April 2020...

Doug Perrine / Whitemouth moray eel (Gymnothorax meleagris) sheltering in bleached Antler coral (Pocillopora grandis) due to marine heatwave. Kohanaiki, Kona, Hawaii, USA. December 2015.

Doug Perrine / Antler coral (Pocillopora grandis), partially bleached. Healthy coral is brown due to presence of symbiotic zooxanthellae. Damaged coral is bleached white due to loss of the symbiotic algae, fluoresci...

Doug Perrine / Antler coral (Pocillopora grandis) showing bleaching with pastel green fluorescence. This is believed to result from pigments produced by coral acting as sunscreen in an attempt to survive bleaching....

Doug Perrine / Antler coral (Pocillopora grandis) showing bleaching with pastel green fluorescence. This is believed to result from pigments produced by coral acting as sunscreen in an attempt to survive bleaching....

Doug Perrine / Bleached coral reef with dead Cauliflower coral (Pocillopora grandis) in middle of large Plate and pillar coral (Porites rus). Bleached by high ocean temperatures during El Nino event. Honaunau Bay, K...

Doug Perrine / Arceye hawkfish (Paracirrhites arcatus) resting on bleached Cauliflower coral (Pocillopora meandrina). Coral bleaching a result of El Nino year with high ocean temperatures. Hoover's Reef, Makako...