A grey whale greets tourists in boat in, Baja California, Mexico, March 2017. A pair of newly born grey whale calves intrigued by visiting tourists eagerly swim over to the group to get a closer look. Urged on by their mother, the small calves confidently went up to the tour group who were visiting San Ignacio Lagoon in Baja California, Mexico. This adorable moment was captured by zoologist and wildlife photographer, Mark Carwardine on his visit to the area in March 2017. (Photo by Mark Carwardine/Barcroft Images)

The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)

Dublin student beat depression by befriending sharks, stingrays and pigs in the Bahamas. Awesome underwater pictures show the 23-year-old diver cosying up to a range of animals including turtles, stingray and sharks. The sunny selfies were taken in the Bahamas by Stuart’s Cove dive instructor and native of the island, Amelia Klonaris – who beat depression by embracing her incredible beach paradise lifestyle. (Photo by Amelia Klonaris/Mediadrumworld)

Gray whale feeding at the surface and showing it's baleen. (Photo by Christopher Swann/Biosphoto)

In this May 2016 photo released by The Ocean Agency/XL Catlin Seaview Survey, a boat sails near a coral reef that has been bleached white by heat stress in the Maldives. oral reefs, unique underwater ecosystems that sustain a quarter of the world's marine species and half a billion people, are dying on an unprecedented scale. Scientists are racing to prevent a complete wipeout within decades. (Photo by The Ocean Agency/XL Catlin Seaview Survey via AP Photo)

The spectacular sequence shows the divers reaching out and even petting the 1,000-pound predators as the inquisitive beasts happily pose for the camera. Other pictures show the sharks appearing to swim with the divers as they move towards the water’s surface. The photographs were taken at Tiger Beach, Grand Bahama by photographer, Steve Hinczynski (49) from Venice, Florida, USA. To take his images Steve used a Canon 7D Mark II camera equipped with Ikelite underwater housing. (Photo by Steve Hinczynski/Mediadrumworld)

Underwater photographer of the year – winner. Dancing Octopus by Gabriel Barathieu (France). Location: Island of Mayotte, off the coast of south-east Africa. “Balletic and malevolent”, one judge said of this octopus, hunting in a lagoon. Barathieu waited until spring tides when there was just 30cm of water on the flats and plenty of light in the shallows. (Photo by Gabriel Barathieu/UPY2017)

Photographs show an adventurer swimming with giant Manta Rays at night. In her latest daring adventure, Alison Teal set out in the middle of the night to free dive with Manta Rays off the coast of Hawaii. Using only hand held dive lights, Alison dove over 50 feet down being careful never to touch the mantas as they fed off the plankton in the light streams. Here: Photos taken by photographer Sarah Lee show the beautiful sight of Manta Rays at night, as they swim with America explorer, Alison Teal. (Photo by Sarah Lee/Caters News Agency)