Alex Mustard / A diver explores Silfra Canyon, a deep fault filled with fresh water in the rift valley between the Eurasian and American tectonic plates at Thingvellir National Park, Iceland. May 2011. In this phot...

Alex Mustard / Dugong (Dugong dugon) male and juvenile Golden trevally (Gnathanodon speciosus) swimming over Seagrass (Halophila stipulacea) meadow. Marsa Nabaa, Marsa Alam, Egypt.

Ingo Arndt / Compilation of various corals including many Fan corals (Gorgonacea sp) from collection at Senckenberg Museum, Frankfurt, Germany.

Ingo Arndt / Grand Prismatic Spring, Midway Geyser Basin, Yellowstone National Park, Wyoming, USA, September 2011.

Ingo Arndt / Sea trout (Salmo trutta trutta) alevin just hatched with full yolk sac, Europe

Chris & Monique Fallows / Long-beaked common dolphin (Delphinus capensis) breaching in front of large ship during sardine run, East London, South Africa, June.

Pete Oxford / Whale Shark (Rhincodon typus) close up of spotted skin, with Golden trevally (Gnathanodon speciosus) Cenderawasih Bay, West Papua, Indonesia.

David Pattyn / Trees in Hautes Fagnes Nature Reserve in winter after snowfall. This area - Noir Flohay was burnt a few years ago and some trees are still blackened, Hautes Fagnes, Belgian Ardennes, Belgium, February...

Ben Hall / Marine Iguana (Amblyrhynchus cristatus) on rock with lava lizard sitting on its head, Galapagos Islands, May.

Inaki Relanzon / Khongor sand dunes, Govi Gurvan Saikhan National Park, Gobi Desert, South Mongolia. June 2015.

Jordi Chias / Bryde's whale (Balaenoptera edeni) and Common dolphins (Delphinus delphis) chasing small fish offshore. Santa Maria Island, Azores, Atlantic Ocean. Third Place in the Underwater Category of the Por El...

Claudio Contreras / Caribbean flamingo (Phoenicopterus ruber) adults guarding chick, Ria Lagartos Biosphere Reserve, Yucatan Peninsula Mexico, June. Bookplate.