National Geographic has created “Air, Land & Sea: the 50 greatest wildlife photographs” exhibition. Here: CT4 Crocodile cave on the Salamat river. Set up with Nathan Williamson last chip rain came while we were with the nomads. (Photo by Michael Nichols/National Geographic)

Biologists Jenna Cormany (L) and Lauryn Wright of the South Carolina Department of Natural Resources help to release a leatherback turtle in Isle of Palms, South Carolina March 12, 2015. The 475-pound turtle was the first living leatherback turtle to be recovered in South Carolina and one of only a handful ever treated at rehabilitation facilities in the United States. It was found March 7 on the beach on Yawkey-South Island Reserve, a 3.5-mile-long (5.6-km-long) barrier island and wildlife preserve near Georgetown, South Carolina. (Photo by Randall Hill/Reuters)

A mysterious sea creature with some frighteningly sharp teeth washed up on a beach in England last week, where David Mackland snapped these photos. A Grind TV story reports that Mackland estimated the creature to be about 4-5 feet in length. (Photo by David Mackland/OurCarnoustie)

Weighing in at just under 6 pounds and at 22.6 inches long, the female pup arrived at Shedd in late October from Monterey Bay Aquarium in California, where she spent the first four weeks of her life being stabilized. The pup has been doing well since her arrival, receiving continual care behind the scenes of Shedd’s Abbott Oceanarium. Currently referred to as “Pup 681”, Shedd’s animal care and veterinarian teams are providing the continual, round-the-clock care she needs to thrive. Photos used with permisson from Shedd Aquarium. (Photo by Brenna Hernandez/AP Photo)

Salt-resistant plants grow in sand made up of small fish bones on the shore of the Salton Sea before sunrise in an area where a controversial development would create a new town for nearly 40,000 people on the northwest shore of the biggest lake in California, the Salton Sea, on March 21, 2012 south of Mecca, California. (Photo by David McNew/Getty Images)

Two giant puppets, a deep sea diver and his niece, roam through the streets of Liverpool, northern England, and April 20–23 looking for each other during the Sea Odyssey festival. The free event, organized by the French company Royal de Luxe is one of a series of events marking the 100th anniversary of the sinking of The Titanic. The liner, registered in Liverpool, sank on its maiden voyage to New York on April 15, 1912.

Photo: A giant deep sea diver emerges from the Albert Dock to begin a journey through the streets of Liverpool during the Titanic Sea Odyssey on April 20 in Liverpool, England. (Photo by Christopher Furlong)

Sea lions wait on the deck of the boat before being released in front of Palomino island, in Callao, Peru September 12, 2015. Four young sea lions returned to the wild after being rescued by marine biologists and treated for various illnesses. The sea lions are survivors of various illnesses which they contracted off the coast of Peru caused by the elevated temperatures in the water because of the El Nino phenomenon, according to Carlos Yaipen, Director of Animal Science and Well-being Organization (ORCA). (Photo by Mariana Bazo/Reuters)

An environmental activist adjusts his mask while taking part in “The Dead Sea Swim Challenge”, swimming from the Jordanian to Israeli shore, to draw attention to the ecological threats facing the Dead Sea, in Kibbutz Ein Gedi, Israel November 15, 2016. Swimmers from around the world plunged into the salty waters of the Dead Sea on Tuesday to attempt a seven-hour swim across the fabled lake in a bid to draw attention to its environmental degradation. Wearing protective masks and snorkels, 25 swimmers paddled through the muddy water to attempt the 9-mile (15-kilometer) swim from Jordan to Israel. (Photo by Nir Elias/Reuters)