Alex Mustard / Big fin reef squid (Sepioteuthis lessoniana) descends from open water to the reef at night. Arafur Sea, Triton Bay, West Papua, Indonesia.

Andrew Parkinson / Coot (Fulica atra) silhouetted as it descends a grass bank, Derbyshire, UK, March. Highly commended in the Portfolio category of the BWPA Competition 2016.

Floris van Breugel / Twilight descends on photographer's mountain camp with light inside tent, in Oregons highest mountain forest on Drake Peak at 8,500 feet. Oregon, USA, January 2010.

Sandesh Kadur / A summer sun descends beyond the characteristic crown of a moss covered Shola tree in the Anamalais, Kerala, Western Ghats, Southern India

Colin Monteath / Hiker descends hill of Tussock Grass (Poa flabellata) above Lake Heron Station, Canterbury, New Zealand

Chadden Hunter / Cameraman, Ted Giffords, radios for help as an unexpected early winter storm descends on the team, the crew were working in an ice crevasse at the time, for the Mountains episode of the BBC tv series...

Colin Monteath / River descends from Southern Alps towards Waimakariri River, Arthur's Pass National Park, New Zealand

Colin Monteath / Skier descends Central Rongbuk Glacier with Mount Everest in the background, Tibet

Doug Perrine / Diver descends into 'Angelfish Blue Hole' off Georgetown, Exuma, Bahamas

Andrew Parkinson / Traditional Mule train descends from Thorung La Pass, Annapurna circuit, Nepal

Jeff Rotman / Common reef octopus descends on prey. (Octopus cyaneus) Red Sea Egypt

Juergen Freund / Dugong descends after surfacing for air {Dugong dugon} Indo Pacific

Juergen Freund / Dugong descends after surfacing for air {Dugong dugon} Indo Pacific

Jeff Rotman / Common reef octopus (Octopus cyaneus) parachutes down on prey, Red Sea, Egypt.