Eric Baccega / Polar Bear (Ursus maritimus) walking on icepack with arctic coast in the background. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, April.

Eric Baccega / King Eider (Somateria spectabilis) flying low over water. Floe edge, Arctic Bay, Nunavut, Canada, April.

Eric Baccega / Black-legged Kittiwake (Rissa tridactyla) on ice. Floe edge, Arctic Bay, Nunavut, Canada, April.

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

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

Norbert Wu / Ice floes that have broken off sea ice edge in late summer, coast guard icebreaker in background, McMurdo Sound, Antarctica

Norbert Wu / Coast guard icebreaker travels through ice floes which have broker off sea ice edge in late summer, McMurdo Sound, Antarctica

Todd Mintz / Two Walrus (Odobenus rosmarus) hauled out on pack ice along the floe edge, Grise Fiord, Ellesmere Island, Nunavut, Canadian Arctic, June

Eric Baccega / Cone Island, seen from the floe edge off Ellesmere Island, Nunavut, Canada, June 2012.

Eric Baccega / Smith Island, seen from the floe edge off Ellesmere Island, Nunavut, Canada, June 2012.

Bryan and Cherry Alexander / Inuit man dressed in Reindeer / Caribou skin clothing while hunting at the floe edge. Igloolik, Nunavut, Canada, 1990. 40 BELOW bookplate.

Bryan and Cherry Alexander / Inuit hunter dragging Seal at the floe edge. Igloolik, Nunavut, Canada, 1990. 40 BELOW bookplate.

Bryan and Cherry Alexander / Inuit hunters hauling boat out of the water after seal hunting at the floe edge in frost smoke. Igloolik, Nunavut, Canada, 1990. 40 BELOW bookplate.

Bryan and Cherry Alexander / Inuit hunter dragging a dead seal while out hunting at the floe edge. Igloolik, Nunavut, Canada, 1990. Editorial use only.

Bryan and Cherry Alexander / Inuit man hauling his floe edge boat while seal hunting at the ice edge. Igloolik, Nunavut, Canada, 1990.

Bryan and Cherry Alexander / Inuit hunter paddling a floe edge boat through frost smoke while seal hunting at the ice edge near Igloolik, Nunavut, Canada, 1990.

Bryan and Cherry Alexander / Inuit hunter paddling a floe edge boat through frost smoke while seal hunting at the ice edge near Igloolik, Nunavut, Canada, 1990.

Bryan and Cherry Alexander / At -40 degrees Celsius frost smoke rising off the freezing sea at the floe edge near Igloolik, Nunavut, Canada, 1990.

Bryan and Cherry Alexander / Inuk standing in floe edge boat at the ice edge, aiming his rifle while hunting. Igloolik, Nunavut, Canada, 1990

Bryan and Cherry Alexander / Male Killer whale (Orcinus orca) hunting along the floe edge by Mount Erebus. Ross Sea, Antarctica.

Bryan and Cherry Alexander / Yupik Eskimo seal hunting at the floe edge in Tkachen Bay. Chukotskiy Peninsula, Chukotka, Siberia, Russia, 2010

Bryan and Cherry Alexander / Yupik Eskimo hunter using inflatable boat to retrieve Ringed seal (Phoca Hispida) shot at the floe edge in Tkachen Bay. Chukotskiy Peninsula, Chukotka, Siberia, Russia, 2010

Bryan and Cherry Alexander / Yupik Eskimo hunters travelling to the floe edge by snowmobile with an inflatable boat. Tkachen Bay, Chukotskiy Peninsula, Chukotka, Siberia, Russia, 2010

Bryan and Cherry Alexander / Yupik Eskimo hunter shooting seal from the floe edge in Tkachen Bay. Chukotskiy Peninsula, Chukotka, Siberia, Russia, 2010

Bryan and Cherry Alexander / Yupik Eskimo hunter seal hunting at the floe edge in Tkachen Bay. Chukotskiy Peninsula, Chukotka, Siberia, Russia, 2010

Bryan and Cherry Alexander / Yupik Eskimo hunter seal hunting with his dog (Canis familiaris) at the floe edge in Tkachen Bay. Chukotskiy Peninsula, Chukotka, Siberia, Russia, 2010

Bryan and Cherry Alexander / Yupik Eskimo seal hunting at the floe edge in Tkachen Bay. Chukotskiy Peninsula, Chukotka, Siberia, Russia, 2010

Eric Baccega / Inuit hunter on icepack. Floe Edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Polar Bear (Ursus maritimus) feeding on a Narwhal (Monodon monoceros) on icepack as gulls wait to scavenge the carcass. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Polar Bear (Ursus maritimus) feeding on a Narwhal (Monodon monoceros) on icepack as gulls wait to scavenge the carcass. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Polar Bear (Ursus maritimus) feeding on a Narwhal (Monodon monoceros) on icepack. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Polar Bear (Ursus maritimus) feeding on a Narwhal (Monodon monoceros) on icepack. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Polar Bear (Ursus maritimus) feeding on a Narwhal (Monodon monoceros) on icepack as a gull waits to scavenge the carcass. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Portrait of a Northern Fulmar (Fulmaris glacialis) on water. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / King Eider (Somateria spectabilis) flying low over water. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / King Eider (Somateria spectabilis) flying low over water. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / Polar Bear (Ursus maritimus) walking on the horizon of the icepack. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Three Black Guillemots (Cepphus grylle) performing a courtship display on water. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / Black Guillemot (Cepphus grylle) male displaying to a female. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / Black Guillemot (Cepphus grylle) male following a female in a courtship display. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / Two Black-legged Kittiwake (Rissa tridactyla) taking off from ice. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / Three Black-legged Kittiwake (Rissa tridactyla) on ice. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / Two Black-legged Kittiwake (Rissa tridactyla) on ice. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / Luminescent Combjelly (Phylum ctenophora) in arctic waters. Floe Edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Thick-billed Murre / Brunnich's Guillemot (Uria lomvia) standing on ice. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / Melting ice at Floe Edge, Arctic Bay, Baffin Island, Nunavut, Canada, June 2011.

Eric Baccega / Luminescent Combjelly (Phylum ctenophora) in arctic waters. Floe Edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Luminescent Combjelly (Phylum ctenophora) in arctic waters. Floe Edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

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

Eric Baccega / Floe edge of melting icepack with eroding coastal mountains. Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Floe edge of melting icepack with eroding coastal mountains. Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Inuit man cutting a piece of Narwhal (Monodon monoceros) skin and fat (muktuk), traditional food in Inuit culture. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / Inuit hunter cutting a ringed sea (Pusa hispida), a traditional food in Inuit culture. Floe edge, Arctic Bay, Nunavut, Canada, June 2011.

Eric Baccega / Inuit man cutting a piece of Narwhal (Monodon monoceros) skin and fat (muktuk), traditional food in Inuit culture. Floe edge, Arctic Bay, Nunavut, Canada, June.

Eric Baccega / Inuit hunter on icepack. Floe Edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Inuit guides observing Narwhals (Monodon monoceros) in the icepack. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Inuit guide observing melting ice. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Bryan and Cherry Alexander / Chukchi hunter dragging Baidarka (Walrus skin boat) while hunting at the floe edge. Chukotka, Siberia, Russia.

Bryan and Cherry Alexander / Chukchi hunter dragging Baidarka (Walrus skin boat) while hunting at the floe edge. Chukotka, Siberia, Russia.

Bryan and Cherry Alexander / Chukchi hunter dragging Baidarka (Walrus skin boat) while hunting at the floe edge. Chukotka, Siberia, Russia.

Bryan and Cherry Alexander / Chukchi hunter dragging Baidarka (Walrus skin boat) while hunting at the floe edge. Chukotka, Siberia, Russia

Bryan and Cherry Alexander / Inuit hunters and Huskies (Canis familiaris) stopping for break on way to floe edge. Northwest Greenland, 1977.

Bryan and Cherry Alexander / Inuit man hunting seals with rifle at floe edge in Melville Bay, Northwest Greenland, 1980.

Bryan and Cherry Alexander / Inuit hunters at floe edge with Walrus (Odobenus rosmarus) meat from hunting trip. Siorapaluk, Northwest Greenland, 1977.

Bryan and Cherry Alexander / Inuit hunters travelling to floe edge in boat on sled pulled by Huskies (Canis familiaris). Siorapaluk, Northwest Greenland, 1977.

Bryan and Cherry Alexander / Inuit hunters butchering Narwhal (Monodon monoceros) at floe edge. Qaanaaq, Northwest Greenland.

Bryan and Cherry Alexander / Inuit hunters with dead Walrus (Odobenus rosmarus) at floe edge near Etah. Northwest Greenland, 1989.

Bryan and Cherry Alexander / Inuk helping hunting companion launch kayak from floe edge. Northwest Greenland, 1986.

Bryan and Cherry Alexander / Inuit hunter shooting at seal from floe edge near Cape York, Northwest Greenland.

Bryan and Cherry Alexander / Patterns on newly formed sea ice at floe edge in winter. Northwest Greenland, 1980.

Bryan and Cherry Alexander / Frost smoke rising from open sea at -40C as Inuit hunter waits at seal's breathing hole near floe edge. Thule, Northwest Greenland, 1980.

Norbert Wu / Ice floes that have broken off sea ice edge in late summer, McMurdo Sound, Antarctica

Sue Flood / Aerial of sea ice near floe edge, Admiralty Inlet, Canadian High Arctic, June 2000

Suzi Eszterhas / Leopard Seal (Hydrurga leptonyx) circling Adelie Penguins (Pygoscelis adeliae) on ice floe as penguins watch from the ice edge, Paulet Island, Antarctica

Flip Nicklin / Bowhead Whale (Balaena mysticetus) spouting, Baffin Island, Canada

Suzi Eszterhas / Hudson Bay in spring showing ice edge, Churchill, Manitoba, Canada

Colin Monteath / Pack ice and calving icebergs, aerial view of Mertz Glacier, Terre Adelie Land, east Antarctica

Doug Allan / Ice floe edge in spring, Lancaster sound, Canadian Arctic

Sue Flood / Inuit boy in traditional clothing on trip to floe edge Nunavut, Baffin Island, Canadian Arctic

Konrad Wothe / Crabeater Seal (Lobodon carcinophagus) resting on ice, Paradise Bay, Antarctica

Norbert Wu / Adelie Penguin (Pygoscelis adeliae) above and below water orcas-eye view of group on ice floe that has split off of ice edge, McMurdo Sound, Antarctica

Doug Allan / Floe edge where solid sea ice meets open water Canadian Arctic

Eric Baccega / Polar Bear (Ursus maritimus) and a Beluga / White Whale (Delphinapterus leucas) at the sea surface with a bird flying overhead. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Polar Bear (Ursus maritimus) walking on icepack. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Polar Bear (Ursus maritimus) walking on icepack. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Eric Baccega / Polar Bear (Ursus maritimus) feeding on a Narwhal (Monodon monoceros) on icepack. Floe edge, Arctic Bay, Baffin Island, Nunavut, Canada, June.

Flip Nicklin / Cruise ship nears edge of glacier, southeast Alaska

Norbert Wu / Iceberg among splitting sheets of ice, ice floes break off from ice edge in summer, McMurdo Sound, Antarctica