Staffan Widstrand / Coastal ice, Svalbard, Norway, July 2011

Mark Carwardine / Tourists watching Walrus (Odobenus rosmarus) swimming near boat, Igloolik, Foxe Basin, Nunavut, Arctic Canada, 2007

Floris van Breugel / Natural iridescent oil film from decaying leaves at the surface of a pool, with a cottonwood leaf floating. Escalante National Monument, Utah. November.

Konrad Wothe / Close up of iceberg in Inside Passage, Southeast Alaska, USA, July 2006

Juan Carlos Munoz / Ice on lake, Plitvice Lakes National Park, Lika, Croatia, Europe, January

Nick Upton / Mallard (Anas platyrhynchos) drake sliding on fresh snow after landing on frozen lake surface, Wiltshire, UK, February

Roy Mangersnes / Polar bear (Ursus maritimus) holding piece of ice after licking off freshwater, Spitsbergen, Svalbard, Norway, August

Graham Eaton / Underwater view of a mountain lake with frozen surface, Llyn Idwal, Snowdonia NP, Gwynedd, Wales, UK, December

Brent Stephenson / Calm conditions with sea ice in the Lemaire Channel. Antarctic Peninsula, Antarctica, December.

Brent Stephenson / Large growler berg in the Lemaire Channel. Antarctic Peninsula, Antarctica, January.

Todd Mintz / Narwhal (Monodon monoceros) pod at surface with one tusk visible, Arctic Bay, Baffin Island, Canada, June

Doug Allan / Killer Whales (Orcinus orca) spy-hopping to observe Weddell Seal (Leptonychotes weddellii) in preparation to knock it from the ice by creating a wave. Marguerite Bay, Antarctic Peninsula, summer. Free...

Doug Allan / Killer Whales (Orcinus orca) create bow wave to knock Weddell Seal (Leptonychotes weddellii) from the ice; a co-operative hunting strategy. Marguerite Bay, Antarctic Peninsula, summer. Freeze Frame bo...

Doug Allan / Killer Whales (Orcinus orca) approaching Weddell Seal (Leptonychotes weddellii) in preparation to knock it from the ice by creating a wave. Marguerite Bay, Antarctic Peninsula, summer. Freeze Frame bo...

Sven Zacek / Frozen bubbles captured in ice on the surface of lake. South Estonia, Europe, January 2008.

Ole Jorgen Liodden / Iceberg in calm arctic seas at 80 degrees north. Svalbard, September.

Kathryn Jeffs / Sun low in the sky over floe ice near the Antarctic peninsula, Antactica, January 2009, Taken on location for BBC Frozen Planet series

Kathryn Jeffs / Coastal landscape off the Antarctic Peninsula, Antarctica, January 2009, Taken on location for BBC Frozen Planet series

Steven Kazlowski / Walrus (Odobenus rosmarus) two young bulls, in waters along Spitsbergen and the northwestern coast of the Svalbard Archipelago, Norway, Arctic Ocean, July

Andrew Parkinson / Mute swan (Cygnus olor) drinking from the surface of a frozen lake, Derbyshire, UK, March.

Graham Eaton / Ice on lake surface seen from below. Llyn Idwal, Snowdonia, Wales, December 2010.

Frederique Olivier / Killer whale (Orcinus orca) amongst thick pack ice, Antarctica. Taken on location for the BBC series, Frozen Planet.

Danny Green / Little Auks (Alle alle) flying low above surface in front of iceberg. Spitsbergen, Svalbard, Norway, July 2010. Highly commended in the Birds category in the GDT competition 2011.

Eric Baccega / Narwhal (Monodon monoceros) showing tusk above water surface. Baffin Island, Nunavut, Canada, April.

Eric Baccega / Narwhal (Monodon monoceros) showing tusks above water surface. Baffin Island, Nunavut, Canada, June.

Eric Baccega / Melting ice at Floe Edge, Arctic Bay, Baffin Island, Nunavut, Canada, April 2009.

Andy Rouse / Polar Bear (Ursus maritimus) mother and two cubs playing around iceberg. Svalbard, Norway, Europe, February.

Hiroya Minakuchi / Humpback Whale (Megaptera novaeangliae) pair gulp feeding, Antarctica

Charlie Summers / Gentoo Penguin (Pygoscelis papua) diving off iceberg and into waters of Pleneau Bay, Antarctica, November

Bryan and Cherry Alexander / Recently rolled iceberg showing ridges formed beneath surface. Northwest Greenland, 1991.

Bryan and Cherry Alexander / Ice floes as sea ice breaks up in summer off coast of Northwest Greenland, 1980.

Michel Roggo / Underwater landscape in Hongrin River with ice on the river bed and surface in winter. Fribourg, Gruyre, Switzerland, December

Edwin Giesbers / Ice patterns, with leaves frozen beneath the surface, the Netherlands

Neil Lucas / Camerman Doug Allan at frozen water surface of drilled ice hole, BBC film crew, McMurdo Sound, Ross Sea, Antarctica, November 2008

Neil Lucas / Weddell seal (Leptonychotes weddellii) male surfacing in ice hole, McMurdo Sound, Ross Sea, Antarctica, November 2008

Andy Rouse / Polar bear (Ursus maritimus) swimming, Austfonna, Svalbard, Norway, June 2007. Image 01253316 is a crop of this image

Andy Rouse / Polar bear (Ursus maritimus) swimming beside ice cliffs, Austfonna, Svalbard, Norway, June 2007

Andy Rouse / Polar bear (Ursus maritimus) swimming beside ice cliffs, Austfonna, Svalbard, Norway, June 2007

Andy Rouse / Polar bear (Ursus maritimus) swimming in front of ice cliff, Austfonna, Svalbard, Norway (non-ex) June 2007

Guy Edwardes / Ice patterns on surface of frozen lake, Snowdonia National Park, Gwynedd, Wales, UK, December 2008

Steven Kazlowski / Bowhead whale (Balaena mysticetus) swimming amidst multi-layer ice (freshwater pans formed over many years where the salt is squeezed out of the ice) offshore from Point Barrow. Chukchi Sea, Arctic Al...

Steven Kazlowski / Crabeater seals (Lobodon carcinophagus) and seagulls feeding on a school of krill in waters off the western Antarctic Peninsula, Southern Ocean

Steven Kazlowski / Killer whales / orcas (Orcinus orca) pod traveling beside a boat in waters off the western Antarctic Peninsula, Southern Ocean

Steven Kazlowski / Weddell seal (Leptonychotes weddellii) at surface of icy waters of the western Antarctic Peninsula, Southern Ocean

Mark Brownlow / Looking down on frozen surface of Lake Baikal, world's deepest and oldest (and largest by volume) freshwater lake, Siberia, Russia. BBC Planet Earth series, April 2005

Doug Allan / Aerial view of sea ice melting, creating patterns over spring sea surface, Lancaster sound, Canadian Arctic

Doug Allan / Belugas (White whale) swim along ice crack {Delphinapterus leucas} Canadian arctic, summer

Larry Michael / Common / Harbour seal {Phoca vitulina} head emerging through sea ice, Alaska.

Doug Allan / Ringed seal at surface hole in ice {Phoca hispida} Lancaster Sound, Canadian Arctic

Doug Allan / Iceberg and albatross flying, Antarctica.

Juan Carlos Munoz / Cracks in thawing ice creating pattern on ice surface. Dyrholaey, Southern Iceland, Europe, March 2011.

Staffan Widstrand / Ice breaking up around the coast, Svalbard, Norway, July 2011

Staffan Widstrand / Minke whale (Balaenoptera acutorostrata) surfacing near coastal ice, Svalbard, Norway, July

Mark Carwardine / Walruses (Odobenus rosmarus) hauled out on ice floe, Igloolik, Foxe Basin, Nunavut, Arctic Canada

Mark Carwardine / Walruses (Odobenus rosmarus) hauled out on ice floe, Igloolik, Foxe Basin, Nunavut, Arctic Canada

Mark Carwardine / Walrus (Odobenus rosmarus), Igloolik, Foxe Basin, Nunavut, Arctic Canada

Mark Carwardine / Walrus (Odobenus rosmarus) close-up Igloolik, Foxe Basin, Nunavut, Arctic Canada

Mark Carwardine / Antarctic minke whale surfacing {Balaenoptera bonaerensis} Antarctica

Steven Kazlowski / Pacific harbour seal (Phoca vitulina richardsi) on ice in Northwestern Fjord, Kenai Fjords National Park, Alaska, USA

Steven Kazlowski / Walrus (Odobenus rosmarus) a cow fights off a bull's advances at the end of mating season, Bering Sea, off the coast of Alaska, USA

Todd Mintz / Walrus (Odobenus rosmarus) at surface, Grise Fiord, Ellesmere Island, Nunavut, Canadian Arctic, March

Todd Mintz / Walrus (Odobenus rosmarus) at surface, Grise Fiord, Ellesmere Island, Nunavut, Canadian Arctic, June

Hiroya Minakuchi / Diver examines underwater surface of iceberg, Antarctic Peninsula, Antarctica

Linda Pitkin / 2020VISION / Marsh Marigold (Caltha palustris), on bank of River Itchen, seen below rippled surface. Ovington, Hampshire, England, May. Did you know? The Marsh marigold is one of the UK's most ancient native plant...

Nick Upton / Moorhen (Gallinula chloropus) walking on frozen lake surface, Wiltshire, UK, February

Nick Upton / Moorhen (Gallinula chloropus) walking on heavily frozen lake surface, Wiltshire, UK, February

Nick Upton / Moorhen (Gallinula chloropus) foraging on heavily frozen lake surface, Wiltshire, UK, February

Nick Upton / Moorhen (Gallinula chloropus) calling whilst walking on heavily frozen lake surface, Wiltshire, UK, February

Nick Upton / Carrion crow (Corvus corone) walking on frozen lake surface, Wiltshire, UK, February

Brent Stephenson / Antarctic minke whale (Balaenoptera bonaerensis) breaking the surface briefly to breath, Skonthorp Cove, Antarctic Peninsula, Antarctica, December.

Erlend Haarberg / Common / Harbour seal (Phoca vitulina) swimming with head above water, Iceland, June

Graham Eaton / Underwater landscape in Llyn Dinas, a mountain lake, surface covered in ice, and green lacustrine algae growing on the bottom, Snowdonia NP, Gwynedd, Wales, UK, December

Graham Eaton / Underwater landscape in Llyn Dinas, a mountain lake, with surface covered in ice, Snowdonia NP, Gwynedd, Wales, UK, December

Graham Eaton / Underwater view of Llynnau Mymbyrl, a mountain lake, with ice on the surface, Snowdonia NP, Gwynedd, Wales, UK, January 2011

Sergey Gorshkov / Aerial view of meltwater lake, with birds flying over surface, Taimyr Peninsula, Siberia, Russia, June 2010

Brent Stephenson / Crabeater Seals (Lobodon carcinophaga) swimming near an iceberg. Pleneau Island, Antarctic Peninsula, Antarctica, January.

Brent Stephenson / Crabeater Seal (Lobodon carcinophaga) peering up from the water in snowfall. Paradise Bay, Antarctic Peninsula, Antarctica, January.

Brent Stephenson / Huge iceberg with group of Chinstrap Penguins (Pygoscelis antarctica) close to the water. Drake Passage, near the South Shetland Islands, Antarctica, December.

Todd Mintz / Narwhal (Monodon monoceros) pod surfacing, one tusk visible, Arctic Bay, Baffin Island, Canada, June

Todd Mintz / Narwhal (Monodon monoceros) pod surfacing, tusk visible, Arctic Bay, Baffin Island, Canada, June

Todd Mintz / Narwhal (Monodon monoceros) pod surfacing, young whale visible, Arctic Bay, Baffin Island, Canada, June

Todd Mintz / Narwhal (Monodon monoceros) pod surfacing, tail fluke and tusks visible, Arctic Bay, Baffin Island, Canada, June

Doc White / Bowhead Whale (Balaena mysticetus) near sea surface. Canadian Arctic, summer.

Alex Hyde / Red algae living just below the surface of snow, known as 'Red Snow'. The red pigment provides protection from ultra-violet light. Austrian Alps, 2800 metres above sea level, June 2009.

Doug Allan / Weddell Seal (Leptonychotes weddellii) being thrown off ice by wave created by Killer Whales (Orcinus orca) using co-operative hunting strategy. Marguerite Bay, Antarctic Peninsula, summer. Freeze Fra...

Doug Allan / Killer Whale (Orcinus orca) spy-hopping to observe a Crabeater Seal (Lobodon carcinophagus); the whales are in search of Weddell Seals. Marguerite Bay, Antarctic Peninsula, summer. Freeze Frame book p...

Doug Allan / Killer Whale (Orcinus orca), member of a pod searching for Weddell Seals (Leptonychotes weddellii) among sea ice. Marguerite Bay, Antarctic Peninsula, summer. Freeze Frame book plate page 118-119.

Doug Allan / Killer Whale (Orcinus orca) observing Weddell Seal (Leptonychotes weddellii) in preparation to knock it from the ice by creating a wave. Marguerite Bay, Antarctic Peninsula, summer. Freeze Frame book...

Doug Allan / Weddell Seal (Leptonychotes weddellii) being thrown off ice by wave created by Killer Whales (Orcinus orca) using co-operative hunting strategy. Marguerite Bay, Antarctic Peninsula, summer. Freeze Fra...

Doug Allan / Killer Whale (Orcinus orca) spy-hopping to observe Crabeater Seals (Leptonychotes weddelli); the whales are in search of Weddell Seals. Marguerite Bay, Antarctic Peninsula, summer. Freeze Frame book p...

Ole Jorgen Liodden / Bearded Seal (Erignathus barbatus) resting on ice. Kongsfjorden, Svalbard, September.

Ole Jorgen Liodden / Polar Bear (Ursus maritimus) swimming in almost frozen ocean. Spitsbergen, Svalbard, August.

Ole Jorgen Liodden / Polar Bear (Ursus maritimus) swimming in almost frozen ocean. Spitsbergen, Svalbard, August.

Doug Allan / Baikal Seal (Pusa sibirica) emerging from hole in the lake ice. Lake Baikal, Siberia, Russia. Freeze frame book plate page page 49.

Doug Allan / Adult male Elephant Seal (Mirounga leonina) at the surface roaring. Antarctica, Signy Island. Freeze Frame book plate page 203.

Doug Allan / Wildlife cameraman Doug Allan prepares for a dive in hole drilled in sea ice. Ross Sea, McMurdo, Antarctica. Freeze frame book plate page 38.