Winner, Behaviour category

Respiro by Antonia Doncila. This photograph was taken while crossing the Fram Strait near the eastern Greenland coast. The polar bear found a portion of fast ice which rapidly became his home
Photograph: Antonia Doncila/PA

Overall winner, and winner in Earth Science and Climatology category

Icy Sugar Cubes by Peter Convey. A photograph taken over the English Coast (southern Antarctic peninsula) illustrating the scale of unusual bi-directional crevassing as an ice sheet is stretched in two directions over an underlying rise, with a Twin Otter aeroplane as scale
Photograph: Peter Convey/PA

Runner up, Behaviour category

Breeding by David Costantini. Arctic terns in Svalbard
Photograph: David Costantini/PA

Honourable mention, Behaviour category

Toss the scorpion – Indian roller playing with its kill by Susmita Datta. The image was taken during an early morning safari drive at Tadoba Andhari Tiger Reserve in India
Photograph: Susmita Datta/PA

Runner up, Earth Science and Climatology category

Bow first by Giuseppe Suaria. The Russian research vessel Akademik Tryoshnikov leans its bow against the Mertz Glacier’s snout in Eastern Antarctica. The photo was taken moments before deploying Ropos, a remotely operated underwater vehicle, under the glacier tongue to investigate the melting of the ice-sheet after a piece of ice protruding 100km (62 miles) out into the Southern Ocean broke away from the main body of the tongue in 2010
Photograph: Giuseppe Suaria/PA

Honourable mention, Earth Science and Climatology category

Pele’s fire by Sabrina Koehler. The image shows the 61G lava flow at the Pu’u O’o eruption site of the active Kilauea volcano in Hawaii’s Volcano national park
Photograph: Sabrina Koehler/PA

Winner, Astronomy category

Lunar Spotlight, South Pole, Antarctica, by Daniel Michalik. Ice crystals suspended in the atmosphere create a rare optical phenomenon: a light pillar underneath the Moon
Photograph: Daniel Michalik/PA

Runner up, Astronomy category

Diamond ring through thin clouds by Wei-feng Xue. The American Eclipse of 2017 seen from the part of the path of totality that went through northern Georgia. This is the diamond ring lighting up some very thin cloud structures, looking almost like space clouds (ie a nebula)
Photograph: Wei-Feng Xue/PA

Honourable mention, Astronomy category

Within Reach by Petr Horalek. The skies above ESO’s Paranal Observatory resemble oil on water as greens, yellows and blues blend to create an iridescent skyscape. The rocky, barren landscape below evokes an alien world, complementing the cosmic display above
Photograph: Petr Horalek/PA

Winner, Ecology and Environmental Science category

Waiting in the Shallows by Nico de Bruyn. Orcas suddenly enter a small bay at subantarctic Marion Island, surprising a small huddle of king penguins busy preening themselves in the water
Photograph: Nico de Bruyn/PA

Honourable mention, Micro-imaging category

Acari trapped in a spiderweb by Bernardo Segura.
Photograph: Bernardo Segura/PA