Solvin Zankl / Baby Olive Ridley sea turtle (Lepidochelys olivacea) struggles against the swell to swim away from the beach where it hatched, Ostional, Costa Rica. October. Winner of the Underwater category of the G...

Doug Perrine / Bryde's whale {Balaenoptera brydei / edeni} with throat pleats expanded after feeding on baitball of Sardines {Sardinops sagax} off Baja California, Mexico, Eastern Pacific Ocean. Veolia Environnement...

Alex Mustard / Two Whale sharks (Rhincodon typus) feeding on fish eggs at the surface, Isla Mujeres, Quintana Roo, Yucatan Peninsula, Mexico, Caribbean Sea.

Mark Carwardine / Whale shark (Rhincodon typus) aerial view of juvenile with two people swimming alongside, La Paz Bay, Sea of Cortez (Gulf of California), Baja California, Mexico, March 2009

Mark Carwardine / Hands of a tourist leaning from boat to touch the mouth of a friendly Grey whale (Eschrichtius robustus) lying on the surface, San Ignacio Lagoon, Baja California, Mexico, April 2009

Mark Carwardine / Grey whale (Eschrichtius robustus) underwater, San Ignacio Lagoon, Baja California, Mexico

Mark Carwardine / Split-level of tourist in small boat leaning out to touch a Grey whale (Eschrichtius robustus) San Ignacio Lagoon, Baja California, Mexico, April 2009

Mark Carwardine / Tourists watching Grey whale (Eschrichtius robustus) spyhopping, San Ignacio Lagoon, Baja California, Mexico, February 2010

Mark Carwardine / Grey whale (Eschrichtius robustus) spyhopping, San Ignacio Lagoon, Baja California, Mexico

Mark Carwardine / Whale shark (Rhincodon typus) aerial view of juvenile with two people swimming alongside, La Paz Bay, Sea of Cortez (Gulf of California), Baja California, Mexico, March 2009

Mark Carwardine / Tourists in small boat leaning out to touch a curious Grey whale (Eschrichtius robustus) San Ignacio Lagoon, Baja California, Mexico, March 2007

Mark Carwardine / Tourists in small boat watching curious Grey whale (Eschrichtius robustus) spyhopping, San Ignacio Lagoon, Baja California, Mexico, February 2007

Mark Carwardine / Grey whale (Eschrichtius robustus) close-up of eye, San Ignacio Lagoon, Baja California, Mexico

Mark Carwardine / Ocean sunfish (Mola mola) near surface, Baja California, Sea of Cortez (Gulf of California), Mexico

Claudio Contreras / Harbour Seal (Phoca vitulina), near San Quintin, Baja California Peninsula, Mexico, December.

Claudio Contreras / Heermann's Gull (Larus heermanni) in flight, Ensenada, Baja California Peninsula, Mexico, December.

Claudio Contreras / American Flamingo (Phoenicopterus ruber) juveniles following adults, Ria Lagartos Biosphere Reserve, Yucatan Peninsula, Mexico, August.

Claudio Contreras / Heermann's Gulls (Larus heermanni) in flight. Ensenada, Baja California Peninsula, Mexico, December.

Claudio Contreras / American Flamingo (Phoenicopterus ruber) juveniles released from temporarty captivity, Ria Lagartos Biosphere Reserve, Yucatan Peninsula, Mexico.

Claudio Contreras / Royal Tern (Thalasseus maximus), El Requeson, Gulf of California, Baja California Peninsula, Mexico, December.

Claudio Contreras / Osprey (Pandion haliaetus) flying with fish prey, Ria Lagartos Biosphere Reserve, Yucatan Peninsula, Mexico, August.

Claudio Contreras / Green Turtle (Chelonia mydas) hatchling on its way to the sea, Ria Lagartos Biosphere Reserve, Yucatan Peninsula, Mexico, August. Endangered species.

Jeff Rotman / Common thresher shark (Alopias vulpinus) caught in gill net, observed by diver at night, Huatampo, Mexico, Gulf of California, Pacific Ocean. Model released. May 2008.

Jeff Rotman / Common Thresher Shark (Alopias vulpinus) caught in gill net, Huatabampo, Mexico, Sea of Cortez, Pacific Ocean

Jeff Rotman / Common Thresher Shark (Alopias vulpinus) silhouette of one caught in gill net, Huatabampo, Mexico, Sea of Cortez, Pacific Ocean

Jeff Rotman / Common Thresher Shark (Alopias vulpinus) silhouette of one caught in gill net, Huatabampo, Mexico, Sea of Cortez, Pacific Ocean

Jeff Rotman / Whitetip reef sharks (Triaenodon obesus) pack silhouetted following scent trail in water column, Cocos Island, Costa Rica, Pacific Ocean

Jeff Rotman / Common Thresher Shark (Alopias vulpinus) caught on gill net being hauled up onto boat, Huatabampo, Mexico, Sea of Cortez, Pacific Ocean. Model released. Model released.

Jeff Rotman / Common thresher shark (Alopias vulpinus) severed fin being held up by gill net fisherman, Huatabampo, Mexico, Sea of Cortez, Pacific Ocean Model released.

Alex Mustard / A school of lesser devil rays (Mobula hypostoma) flying through sunbeams as they feed. Isla Mujeres, Quintana Roo, Yucatan Peninsula, Mexico. Caribbean Sea.

Alex Mustard / Whale shark (Rhincodon typus) silhouette of shark feeding on floating fish eggs (not visible) just below the surface in calm weather, with snorkeller taking photos nearby, Isla Mujeres, Quintana Roo,...

Alex Mustard / Whale shark (Rhincodon typus) feeding on fish eggs (visible as white blobs) at the surface in calm weather, with another whale behind. Isla Mujeres, Quintana Roo, Yucatan Peninsular, Mexico, Caribbean...

Alex Mustard / Whale shark (Rhincodon typus) silhouette, feeding on floating fish eggs (not visible) just below the surface in calm weather. Note the bow wave ahead of the shark. Isla Mujeres, Quintana Roo, Yucatan...

Chris Mattison / Waxy leaf frog (Phyllomedusa sauvagii), captive, occurs South and Central America

Jack Dykinga / Woman swimming in Cenote Noh-Moson with Ficus tree roots, ten meters long, reaching toward the blue wate,r Yucatan, Mexico. No release available.

Claudio Contreras / French Angelfish (Pomacanthus paru) with a Smallmouth Grunt (Haemulon chrysargyreum) and Blade Fire Coral (Millepora complanata). Cancun National Park, Caribbean Sea, Mexico.

Claudio Contreras / Smooth Trunkfish (Lactophrys triqueter). Cancun National Park, Caribbean Sea, Mexico.

Claudio Contreras / Porkfish (Anisotremus virginicus) school. Cancun National Park, Caribbean Sea, Mexico.

Claudio Contreras / Atlantic Sailfish (Istiophorus albicans) attacking school of sardine (Sardinella aurita) bait ball. Isla Mujeres, Caribbean Sea, Mexico.

Claudio Contreras / Green Seaturtle (Chelonia mydas) in profile above sandy shallow sea bed. Endangered, Cancun National Park, Caribbean Sea, Mexico.

Claudio Contreras / Queen Angelfish (Holacanthus ciliaris) among other coral fish. Cancun National Park, Caribbean Sea, Mexico.

Claudio Contreras / Saucereye porgy (Calamus calamus). Cancun National Park, Caribbean Sea, Mexico.

Doc White / Steam from underwater volcanic activity. Socorro Island, Baja Mexico.

Pete Oxford / Two Common Bottlenose Dolphin (Tursiops truncatus) in shallow water. Punta Allen, Sian Ka'an Biosphere Reserve, Quintana Roo, Yucatan Peninsula, Mexico.

Inaki Relanzon / Whale Shark (Rhincodon typus), eating krill and plankton at the surface. Gulf of Mexico, Mexico, North America, August.

Alex Mustard / A young California sealion (Zalophus californianus) swims in a shallow pool. Los Isotes, La Paz, Mexico. Sea of Cortez, East Pacific Ocean.

Alex Mustard / A split level view of a bull California sealion (Zalophus californianus) swimming beneath Los Islotes sealion colony. La Paz, Mexico. Sea of Cortez, East Pacific Ocean.

Alex Mustard / A young California sealion (Zalophus californianus) portrait, inside an underwater cave. Los Isotes, La Paz, Mexico. Sea of Cortez, East Pacific Ocean.

Alex Mustard / A young California sealion (Zalophus californianus) playing with a starfish, inside an underwater cave. The pups will pick up a variety of objects (such as starfish, lumps of coral, shells and feather...

Alex Mustard / A young California sealion (Zalophus californianus) playing with a starfish, inside an underwater cave. The pups will pick up a variety of objects (such as starfish, lumps of coral, shells and feather...

Alex Mustard / A bull California sealion (Zalophus californianus) bursting through a school of baitfish in the shallows. Los Isotes, La Paz, Mexico. Sea of Cortez, East Pacific Ocean.

Alex Mustard / A young California sealion (Zalophus californianus) head portrait, Los Isotes, La Paz, Mexico. Sea of Cortez, East Pacific Ocean.

Alex Mustard / A silhouette of a California sealion pup (Zalophus californianus) next to cliffs. Los Isotes, La Paz, Mexico. Sea of Cortez, East Pacific Ocean.

Alex Mustard / A silhouette of a young California sealion (Zalophus californianus) swimming just below the surface, close to shore. Los Isotes, La Paz, Mexico. Sea of Cortez, East Pacific Ocean.

Alex Mustard / An adult California sealion (Zalophus californianus) makes a sharp turn at high speed. Los Islotes, La Paz, Baja California, Mexico. Sea of Cortez, East Pacific Ocean.

Doug Perrine / Bryde's whale (Balaenoptera brydei / edeni) swimming past a baitball of Sardines (Clupeidae) off Baja California, Mexico, Eastern Pacific Ocean, November

Doug Perrine / Bryde's whale (Balaenoptera brydei / edeni) expeling air and water from mouth through baleen plates after engulfing part of a baitball of Sardines (Clupeidae) with California sea lion (Tetreapturus au...

Doug Perrine / Bryde's whale (Balaenoptera brydei / edeni) swimming past a baitball of Sardines (Clupeidae)California sea lion (Tetreapturus audax) and Striped marlin (Zalophus californianus) in background. Off Baja...

Alex Mustard / California sea lion pup (Zalophus californianus) portrait in a rocky underwater cave. La Paz, Baja California Mexico. Sea of Cortez, East Pacific Ocean. October

Alex Mustard / An adult female California sea lion (Zalophus californianus) head portrait, in a rocky underwater cave. La Paz, Baja California Mexico. Sea of Cortez, East Pacific Ocean. October

Alex Mustard / Large female Giant Pacific Manta Ray (Manta birostris) swimming below surf crashing into Roca Partida, Revillagigedos Islands, Mexico. East Pacific Ocean. February

Alex Mustard / Split level of female California sea lions (Zalophus californianus) basking in the sun on the surface. La Paz, Baja California Mexico. Sea of Cortez, East Pacific Ocean. October

Alex Mustard / Male Great white shark (Carcharodon carcharias) showing scars from hunting, Guadalupe Island, Mexico, Pacific Ocean.

Alex Mustard / Giant Pacific Manta Ray (Manta birostris) portrait with Remora fish (Echeneididae) Roca Partida, Revillagigedos Islands, Mexico. East Pacific Ocean. February

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

Claudio Contreras / Guadalupe fur seal (Arctocephalus townsendi) pup playing underwater, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, March

Claudio Contreras / Guadalupe fur seal (Arctocephalus townsendi) viewed from above, in the surf, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, February

Claudio Contreras / Northern elephant seal (Mirounga angustirostris) weaner / juvenile head portrait, with head turned to look at camera, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, Febr...

Claudio Contreras / Pair of Northern elephant seals (Mirounga angustirostris) male holding female during copulation, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, January

Claudio Contreras / Northern elephant seal (Mirounga angustirostris) colony on beach, with juvenile / weaner in the surf, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, January

Claudio Contreras / Pink abalone (Haliotis corrugata) shell detail, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, January

Claudio Contreras / Pink abalone (Haliotis corrugata) shell detail, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, January

Claudio Contreras / Pink abalone (Haliotis corrugata) shell detail, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, January

Claudio Contreras / California spiny lobster (Panulirus interruptus) in fishing net, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, January

Claudio Contreras / Great white shark (Carcharodon carcharias) passing divers cage, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, Pacific ocean, September

Claudio Contreras / Laysan albatross (Phoebastria immutabilis) head portrait calling mate, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, March

Claudio Contreras / Laysan albatross (Phoebastria immutabilis) flying, silhouetted against the sky, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, April

Solvin Zankl / An Olive ridley sea turtle hatchling (Lepidochelys olivacea) on its way to the sea. The hatchlings orientate themselves by the brightness of the horizon above the ocean, Ostional NP, Costa Rica. Octob...

Solvin Zankl / Female Olive ridley sea turtle (Lepidochelys olivacea) swimming from the open ocean towards the beach of Ostional, Costa Rica, Pacific Ocean to gather for an arribada (mass nesting event). November

Solvin Zankl / The community of Ostional on the Pacific coast of Costa Rica, runs a project of sustainable use of eggs of the Olive ridley sea turtle (Lepidochelys olivacea). The eggs, a popular snack in Costa Rica,...

Solvin Zankl / Mature female Olive ridley sea turtles (Lepidochelys olivacea) arriving on the beach of Ostional, Costa Rica, Pacific coast, during an arribada / mass nesting event, November

Solvin Zankl / Female Olive ridley sea turtle (Lepidochelys olivacea) swimming from the open ocean towards the beach of Ostional, Costa Rica, Pacific Ocean to lay its eggs in the warm sand, November

Solvin Zankl / A Costa Rican researcher monitors the temperature in the developing sea turtle nests at Ostional beach, Costa Rica, November 2009. ^^^ Sea turtles have, like many other reptiles, temperature-dependent...

Solvin Zankl / These hatchlings of an Olive ridley sea turtle (Lepidochelys olivacea) should be buried and protected under 40 cm of warm sand, but a domestic dog dug them out at Ostional beach in Costa Rica. Novembe...

Mark Carwardine / Humpback whale (Megaptera novaeangliae) slapping the surface during courtship battle, Sea of Cortez, Baja California, Mexico

Mark Carwardine / Blue whale (Balaenoptera musculus) fluking / diving, Endangered species, Sea of Cortez, Baja California, Mexico

Mark Carwardine / Aerial view of Blue whale (Balaenoptera musculus) at surface, Endangered species, Sea of Cortez, Baja California, Mexico

Mark Carwardine / Aerial view of Blue whale (Balaenoptera musculus) at surface, Endangered species, Sea of Cortez, Baja California, Mexico

Mark Carwardine / Aerial view of Blue whale (Balaenoptera musculus) at surface, Endangered species, Sea of Cortez, Baja California, Mexico

Mark Carwardine / Aerial view of Blue whale (Balaenoptera musculus) at surface, Endangered species, Sea of Cortez, Baja California, Mexico

Mark Carwardine / Blue whale (Balaenoptera musculus) surfacing and blowing, Endangered species, Sea of Cortez, Baja California, Mexico

Mark Carwardine / Blue whale (Balaenoptera musculus) surfacing, showing blowhole and vertebrae of spine, Endangered species, Sea of Cortez, Baja California, Mexico

Mary McDonald / Violet Sabrewing Hummingbird (Campylopterus hemileucurus) male hovering at feeder, Bosque de Paz, Costa Rica, Central America.

Mary McDonald / Chestnut-mandibled Toucan (Ramphastos ambiguus swainsonii) adult bird perched on the edge of the forest. Laguana del Lagarto, Costa Rica, Central America.

Doug Perrine / Dolphin fish / Mahi mahi / Dorado (Coryphaena hippurus) close up, off Isla Mujeres, near Cancun, Yucatan Peninsula, Mexico, Caribbean Sea (digitially manipulated)

Doug Perrine / Dolphin fish / Mahi mahi / Dorado (Coryphaena hippurus) portrait of large male, off Isla Mujeres, near Cancun, Yucatan Peninsula, Mexico, Caribbean Sea