Ellen Cuylaerts, Canada.

"Every year harp seals make their journey from the Greenland area to fast ice floes in the Gulf of St. Lawrence to give birth to their pups at end of February / early March," says photographer Ellen Cuylaerts. "The mothers feed the pups for just two weeks with milk rich in fat and nutrients. Soon the mothers abandon their pups to join the males for courting and mating, leaving the vulnerable white young on the ice until they moult, lose most of their reserves and learn to swim and hunt by themselves. During this time they fully depend on strong sea ice that lasts at least another four weeks."

Nadia De Lange, Svalbard, Norway.
 
Two polar bear cubs cozy up to their mother. Security and warmth.

Ryuta Ogawa, Japan.

A baby green sea turtle photographed at the Ogasawara Islands, Japan. "The baby turtles born on the islands have to migrate more than 1000km north to their feeding habitat," says photographer Ryuta Ogawa. "I came across this hatchling in the shallows. It almost looked as if it was calmly preparing for its long journey ahead. I waited for the moment it surfaced for a breath of air to get this particular shot."

Dmitry Kokh, Russia.

Polar bears make a 'home' of an abandoned station on Kolyuchin Island, in the Russian high Artic.

Andreas Schmid, Norway.

An orca mother and her calf. "This was the most beautiful day I've had in Northern Norway," says photographer Andreas Schmid. "The mother stayed in front of her calf while they swam past me, making sure I couldn't get too close while still giving the calf a chance to have a good look at me. During the winter months the sun above the Arctic circle is very low or doesn't even rise at all. The window for in-water whale encounters with bright light and sunrays is short. Out of dozens of days this was the only time it all came together."

Reiko Takahashi, Japan.

A narrow waterway alongside a busy resort in Kagoshima is home to a bloom jellyfish during the short summer period.

Gergo Rugli, Australia.

A seagull flys past a large wave breaking in the light of the rising sun. "The mysterious yellow light and the flying bird inspired me to call this image Griffin as this half-eagle, half-lion mythical creature is mostly represented as a yellow bird-like creature," says photographer Gergo Rugli.

Katherine Lu, Philippines.

A blanket octopus displays its beautiful colours and textures. "I was very sick during this dive," says photographer Katherine Lu. "I spent a lot of time trying to equalise near the surface. When my guide frantically signalled for me to come down I hesitated for moment, but went for it, pushing myself down. Luckily my ears equalised and there before my eyes was this beautiful blanket octopus. We swam alongside her and then, like magic, she opened up her blanket to show herself in all her glory."

Brooke Pyke, Western Australia.

"This day was special. The kind of day you wish would never end," says photographer Brooke Pyke. "The ocean was the glassiest I have ever seen it - a dream. I swam alongside this whale shark for around 40 minutes admiring its perfect reflection. Trying to capture this perfection was a challenge - if I dived down it disturbed the water. As I began to let the shark go, I caught a glimpse of a new angle and had to capture it. I will never have this moment again."

Andreas Schmid, Maldives.

"Because this was the last dive on a liveaboard trip before I flew out early the next day I had to stay shallow while everybody else went deep," says photographer Andreas Schmid. "This allowed me to play around with what the site has to offer in the shallows without any other divers around: schooling bannerfishes and pink whiprays."

Rafael Fernandez Caballero, Strait Of Gibraltar, Spain.

A pod of pilot whales pose for a family portrait. "Pilot whales are incredibly special and intelligent beings that enjoy tight family bonds," says photographer Rafael Fernandez Caballero. "They are curious and territorial, so most encounters involve them coming close to see what you want. With love and respect most moments are about a unique interaction, playful moments with different members of each family. This particular picture represents one of the first encounters of that day. A whole family came together to welcome me and to make sure I wasn't a threat."

Ben Thouard, French Polynesia.

The moment a surfer gets wiped out and worked by the turbulence of one of the heaviest waves in the world. "This is the unseen part of surfing," says photographer Ben Thouard. "I have so much respect for both the wave and the surfers - surfing such a heavy wave is a huge challenge."

Simon Lorenz, Sri Lanka.

"When searching for whales in the open ocean we always inspect islands of flotsam as they can be interesting wildlife aggregators," says photographer Simon Lorenz. "This large ghostnet island was a death trap for an Olive Ridley sea turtle which we found entangled and struggling. She still looked healthy and strong so, when approaching her we had to be careful not to aggravate her. Getting her disentangled took a machete and more than 30 minutes of hard work. When all the netting was removed we checked the turtle over and sent her on her way."

Renee Capozzola, Hawaii.

Three green sea turtles gather under the sun in Maui, Hawaii. "Turtles thrive in Hawaii thanks to the legal protections they are provided."

Brook Peterson, The United States.
 
A cormorant and baitfish form the shape of a human face. "This image was made under the oil rig platform, Ellen, off Los Angeles, California," says photographer Brook Peterson. "There was a large school of baitfish under the platform for several weeks and, as a result, numerous other animals there to feed off the baitfish - sea lions, bonita, and cormorants. The image depicts a cormorant hunting through a large bait ball."

Sean Scott, Cape Arid National Park, Western Australia.

Southern right whales off a beach in Western Australia. "This is a drone image taken in Cape Pasley in Western Australia," says photographer Sean Scott. "This is a remote part of the incredible Western Australia coastline. The beauty and ruggedness of the Cape Arid National park is second to none and is one of my favourite places in the world to explore. With my outback photography 4WD I camped out down here for more than a week to photograph and watch the beautiful southern right whales as the families socialised in some of the clearest water in the world. They travel up from Antarctica and hit the coast here before heading back."

Martin Broen, Mexico.

"Shot in an abandoned sinkhole-like cenote, where the organic matter that has fallen in the water has decomposed and generated a Hydrogen Sulphide cloud around it," says photographer Martin Broen, "It creates a spooky atmosphere accentuated by the natural framing and darkness of the cenote. It is a unique and strange natural environment, and a dream-like experience, like floating within in a haunted forest."

Magnus Lundgren, Philippines.

A beautiful juvenile scalloped ribbonfish. "This image was captured in open water while earthquakes were rolling like thunder underwater," says photographer Magnus Lundgren. "As an adult this fish looks like another species, much bigger, shiny silver, with red markings. Sometimes ribbonfish are called “earthquake fish” because they have appeared as adults on the ocean's surface following major earthquake events."

Vanessa Mignon, Australia.

"Port Jackson sharks congregate in Jervis Bay during winter and spring in order to breed," says photographer Vanessa Mignon. "I had tried several times to photograph a shark over the kelp but never got the right conditions - until the weather was perfect. I saw several sharks but most of them were quite deep or resting on the sand or under rocks. The water was cold and after 45 minutes I started shivering. But I persisted. Eventually this shark swam slowly on top of the kelp, possibly looking for a mate, a place to lay an egg, or a place to rest."

Brook Peterson, Egypt.

"I was waiting for sunset so that I could take some split shots showing the beautiful corals under the water when several snorkelers came down the pier and prepared to get in," says photographer Brook Peterson. "I realised the best story my image could tell was how people enjoy the sea and its beautiful corals, so I made this image with that intent."

Florian Ledoux, Svalbard, Norway.

Aerial view of a large male polar bear roaming Arctic's rapidly thinning and melting spring ice. "Spring had arrived and the ice was melting during this shoot," says photographer Florian Ledoux. "This male bear went through the ice on a couple of occasions, swimming for stretches, but he had a quest - he was tracking the scent of a female."

Rafael Fernandez Caballero, Bermeo, Spain.

Mako shark at sunset. "Mako sharks are the fastest animal in the ocean," says photographer Rafael Fernandez Caballero. " Spending sunset with a predator like this is magical. Not only for creating pictures, but for witnessing it speeding along amongst the orange rays. It makes your heart beat a little faster. Mako sharks are endangered and, according to some scientific studies, face extinction in just a few decades."

Renee Capozzola, Philippines.

A turtle takes a rest on the reef off Apo Island in the Philippines. "Apo Island is home to a community-organised marine sanctuary. The concept was introduced to the local fishermen in 1982, and has been the inspiration for many more sanctuaries in the Philippines since," says photographer Renee Capozzola.

Gabriel Barathieu, Mayotte.

"I took this photo during the first test dive of a new rig - Canon R5 in a Seacam housing. It was also the first time I used a wide angle lens during a night dive," says photographer Gabriel Barathieu. "I was secretly hoping to meet a squid for long exposure tests with rear-curtain synchronisation. That's why I took the 14-35mm lens, to be closer to the subject. After 15 minutes of diving, I came face-to-face with this squid and spent 30 minutes having fun with long exposures and flashes in stroboscope mode."

Joshua Munoz, French Polynesia.

"Every winter humpback whales migrate north from Antarctica to French Polynesia, to warmer waters to give birth and mate," says photographer Josh Munoz. "Calves are curious and often leave their mother's side to interact with us in the water - the mother always keeping one eye on her newborn."

Fabrice Guerin, Mexico.

"In the heart of a silence just interrupted by my air bubbles, darkness gives way to this freediver that goes back and forth from the bottom of this cenote to the surface," says photographer Fabrice Guerin. "This freshwater sinkhole, calm, clear and without current, is ideal for training. A sulfur cloud located about twenty meters below reflects the sun rays which then work a real miracle. Originally the hydrogen sulphide layer is flat, but as we enter it repeatedly, clouds form, giving us an impression of underwater waves."

André Musgrove, Bahamas.

A woman lies on the seabed, surrounded by fragments of a dead coral reef. "This photo shows how we have become engulfed by our own destruction as a result of poor climate change practices," says photographer André Musgrove. "I wanted to bring attention to the issue of coral reef death due to both natural and human causes. With the rise of climate change, nations like The Bahamas have become increasingly susceptible to stronger hurricanes that have wreaked havoc on Bahamian islands."

Steve Woods, Dominica.

"This particular female sperm whale kept falling asleep in front of us, then waking up and investigating us again," says photographer Steve Woods. "On one occasion, as she did this in a patch of Sargassum seaweed, I managed to capture this image of a good friend who dived down for a moment with her."

Khaichuin Sim, Malaysia.

A freediver dives into a school of jackfish. "I always wanted to create an image of a human 'coexisting' with the underwater world," says photographer Khaichuin Sim. "My wife is a skilled freediver, so on this shoot I asked her to dive towards the middle of this school until I got this beautiful image of her surrounded with storm of jackfish."

Simon Lorenz, Sri Lanka.
 
"When searching for whales in the open ocean we always inspect islands of flotsam as they can be interesting wildlife aggregators," says photographer Simon Lorenz. "This large ghostnet island was a death trap for an Olive Ridley sea turtle which we found entangled and struggling. She still looked healthy and strong so, when approaching her we had to be careful not to aggravate her. Getting her disentangled took a machete and more than 30 minutes of hard work. When all the netting was removed we checked the turtle over and sent her on her way."

Ishino Shota, Japan.

A turtle passes a bleached reef. "Due to the high water temperatures in the summer, the entire coral reef system in this area was seriously damaged," says photographer Ishino Shota. "Almost all of the zooxanthellae that aids the coral's biological activity has gone. A turtle swims past, as if observing the human destruction inflicted upon the reef."

Tom St George, Mexico.

"Safety, conservation and team diving are integral to cave diving, and cave diving photography is no different," says photographer Tom St George. "It is very much a team effort. Featured in this photograph is Ellen Cuylaerts, who hovers motionless and awestruck after passing through a series of small passages and emerging to a view of these gigantic formations, that took millennia to form, and that she is seeing for the first time!"

Christophe Mason-Parker, Seychelles.

"My wife and I were snorkelling over the vast seagrass beds that surround Desroches Island in Seychelles," says photographer Christophe Mason-Parker. "I wanted to capture an image of her snorkelling close to shore that highlighted the healthy Thalassodendron meadows, along with the coconut palms, which fringe the shoreline."

Rafael Fernandez Caballero, Mexico.

A dead sperm whale beached and bloody, its tail showing signs of entanglement. "Seeing a dead animal is always sad," says photographer Rafael Fernandez Caballero, "but seeing a huge mammal dead, like this sperm whale, is indescribable. From land the scene was terrifying, but from the air the situation was even more shocking and dramatic. The river of blood stretched for perhaps more than a mile."

Tom Vierus, French Polynesia.

Shark scientists attach a temperature logger to the dorsal fin of a newborn blacktip reef shark in the shallow waters just off Moorea, French Polynesia. "During fieldwork, the young sharks are captured with a gillnet, measured, tagged and released and some individuals received temperature loggers as seen in this photo," says photographer Tom Vierus. "These loggers will record the surrounding water temperature for as long as they are attached and once retrieved will aid the scientists in understanding how warming waters affect the physiology and ecology of young sharks."

Simone Caprodossi, Baja California, Mexico.

A brown pelican makes the most of fishing boat scraps. "Brown pelicans gather is numbers in ports and landing sites for fishing boats along the coast of Baja California," says photographer Simone Caprodossi. "We spent two days at an historical shark landing site off Bahia Magdalena engaging with the pelicans as they approached the fishing boats ready to take advantage of the fish scraps that are disposed of from the nets. The competition for the discarded catch is fierce with several pelicans swinging their beaks at the same time, pouch open to catch the easy meal. This clever pelican managed to push back its rivals with his open wings, protecting his catch at the same time."

Thien Nguyen, Vietnam.

The protected mangrove forest of Ru Cha, in the Tam Giang lagoon, Thua Thien-Hue Province, Vietnam. "This aerial image of the mangrove forest expresses the connection between humans and nature, and how we rely on nature to survive," says photographer Thien Nguyen Ngoc.

Julian Jacobs, United States.

"Ten weeks after rupturing my eardrums in a scuba diving accident, I got the ok to head back into the ocean," says photographer Julian Jacobs. "On my return to my favourite reef, I was met with the king tide. The visibility was almost nonexistent so I began to think about heading in. At that moment, hundreds of seabirds took to the skies around me - they were chasing bait balls. I swam over to the aggregation, carefully inching closer to the seabirds. As the waves washed over me, I framed the moment, an over/under shot of a juvenile brown pelican and its turbulent home."

Pasquale Vassallo, Italy.

"This winter, I collaborated with AMP Regno di Nettuno from the islands of Ischia and Procida, to produce a guide of the most beautiful dives on the two islands," says photographer Pasquale Vassallo. "During a dive at one of the sites, I was on the boat and noticed something strange on the surface. I decided to check what it was. As I swam closer, through the jellyfish, I realised, to my great sadness, that it was a sea turtle carcass. Its carapace was broken, most probably by the propeller of a boat. The animal was also lying in a large amount of rubbish, abandoned in the sea by us humans."