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...

Steve Downer / Slug (Species unknown) descending on slime rope from leaf. UK. June.

Juergen Freund / Schooling silversides (Atheriniformes) split level with karst limestone cliff and West Papuan fishermen in their dugout outrigger canoe. Raja Ampat, Indonesia. Second Place in the Portfolio Award of t...

Alex Mustard / Red eye medusa (Polyorchis penicillatus) with hitchhiking amphipods (Hyperia medusarum). Browning Pass, Vancouver Island, British Columbia, Canada. North East Pacific Ocean.

Jack Dykinga / Saguaro cactus (Carnegiea gigantea) in flower at night, with The Milky Way behind, Sonoran Desert National Monument, Sierra Estrella Mountain Wilderness, Arizona, USA, May.

Juergen Freund / Giant clam (Tridacna gigas) Raja Ampat, West Papua, Indonesia.

Floris van Breugel / Aurora borealis / Northern Lights seen from entrance to tent, Brooks Range, Gates of the Arctic National Park, Alaska, USA, September 2014.

Jordi Chias / Juvenile Green turtle (Chelonia mydas) Armenime cove, South Tenerife, Canary Island, Atlantic Ocean

Pal Hermansen / Aerial view of river delta, South West Iceland, June 2014.

Stephen Dalton / Out of focus close-up of a rose (Rosa sp), UK.

Pascal Kobeh / Group of Short-finned pilot whales (Globicephala macrorhynchus) swimming down into deep water, Costa Rica. Pacific ocean.

Pascal Kobeh / Female Humpback whale (Megaptera novaeangliae) with its calf in open water, Reunion Island. Indian Ocean.