Danny Green / Ringed seal (Pusa hispida) and pup resting on ice. Svalbard, Norway. April.

Danny Green / Polar bear (Ursus maritimus) hunting Seal on sea ice. Svalbard, Norway, July 2018.

Danny Green / Ringed seal (Pusa hispida) resting on ice, reflected in water. Svalbard, Norway. July.

David Tipling / Grey seal (Halichoerus grypus) female in surf, Horsey, Norfolk, England, UK, February.

David Tipling / Grey seal (Halichoerus grypus) pup, Horsey, Norfolk, England, UK, February.

Jordi Chias / Crabeater seals (Lobodon carcinophaga) resting on ice floating ice sheet, Antarctic Peninsula, Antarctica.

Jordi Chias / Crabeater seals (Lobodon carcinophaga), Antarctic Peninsula, Antarctica.

Jordi Chias / Leopard seal (Hydrurga leptonyx) with mouth open, Antarctic Peninsula, Antarctica.

Jordi Chias / Leopard seal (Hydrurga leptonyx), Antarctic Peninsula, Antarctica.

Jordi Chias / Leopard seal (Hydrurga leptonyx) resting over an iceberg, Antarctic Peninsula, Antarctica.

Jordi Chias / Leopard seal (Hydrurga leptonyx) resting over an iceberg, Antarctic Peninsula, Antarctica.

Jordi Chias / Leopard seal (Hydrurga leptonyx) swimming underwater, Antarctic Peninsula, Antarctica.

Jordi Chias / Leopard seal (Hydrurga leptonyx) resting over an iceberg, Antarctic Peninsula, Antarctica.

Jordi Chias / Crabeater seal (Lobodon carcinophaga) hunting under water, Antarctic Peninsula, Antarctica.

Jordi Chias / Leopard seal (Hydrurga leptonyx) swimming, Antarctic Peninsula, Antarctica.

Jordi Chias / Leopard seal (Hydrurga leptonyx) predating a Gentoo penguin (Pygoscelis papua) Antarctic Peninsula, Antarctica.

Jordi Chias / Weddell seal (Leptonychotes weddellii) hauled out on ice, Antarctic Peninsula, Antarctica.

Jordi Chias / Weddell seal (Leptonychotes weddellii), Antarctic Peninsula, Antarctica.

Jordi Chias / Weddell seal (Leptonychotes weddellii), Antarctic Peninsula, Antarctica.

Jordi Chias / Weddell seal (Leptonychotes weddellii), Antarctic Peninsula, Antarctica.

Nick Hawkins / Grey seal (Halichoerus grypus) opening mouth close up off Bonaventure Island, Gulf of Saint Lawrence, Quebec, Canada. September.

SCOTLAND: The Big Picture / Grey seal (Halichoerus grypus) pup on a breeding beach, Orkney, Scotland, UK, April.

SCOTLAND: The Big Picture / Grey seal (Halichoerus grypus) huge group hauled out on a beach, Island of Mingulay, west coast of Scotland. May.

SCOTLAND: The Big Picture / Grey seal (Halichoerus grypus) using freshwater pools along the shore line and in the adjacent fields as place to learn to swim, Orkney, Scotland, UK, April.

SCOTLAND: The Big Picture / Young grey seal pup (Halichoerus grypus) recently born on a beach in Orkney, Scotland, UK, April.

Stefan Christmann / Weddell seal (Leptonychotes weddellii) female hauled out with pup, Atka Bay, Queen Maud Land, Antarctica. October.

Alex Hyde / Southern Elephant Seal bull (Mirounga leonina) close up portrait, King Haakon Bay, South Georgia. November.

Alex Hyde / Southern Elephant Seals (Mirounga leonina) pup with mother. King Haakon Bay, South Georgia. November.

Alex Hyde / Colonies of King penguins (Aptenodytes patagonicus) and Southern Elephant Seals (Mirounga leonina) on beach at St. Andrews Bay, South Georgia. November.

Sven Zacek / Bearded seal (Erignathus barbatus) sunbathing on iceberg broken off from glacier. Kongsfjorden fjord, Spitsbergen, Norway. June 2014.

Guy Edwardes / Grey Seal (Halichoerus grypus) playing in waves at Donna Nook, Lincolnshire, England, UK, January.

Guy Edwardes / Grey seals (Halichoerus grypus) females playing on beach at Donna Nook, Lincolnshire, England, UK, January

Guy Edwardes / Grey Seal (Halichoerus grypus) pup on beach at Donna Nook, Lincolnshire, England, UK, January.

Five Films / Female Grey seal (Halichoerus grypus) defending pup on beach, chasing male away, Horsey, Norfolk, November.

Dave Bevan / Two male Grey seals (Halichoerus grypus) fighting in surf, with a female and juvenile nearby, Norfolk, England, UK. December.

Dave Bevan / Grey seal (Halichoerus grypus) pup sheltering amongst sand dunes and Maram grass (Ammophila) whilst its mother is away feeding, Norfolk, England, UK. December.

Dave Bevan / Pair of Grey seals (Halichoerus grypus) mating on a beach, Norfolk, England, UK. December.

Dave Bevan / Pair of Grey seals (Halichoerus grypus) mating on a beach, Norfolk, England, UK. December.

Dave Bevan / Juvenile Herring gull (Larus argentatus) pecking a suckling Grey seal (Halichoerus grypus) pup, Norfolk, England, UK. December.

Dave Bevan / Grey seal (Halichoerus grypus) pup playing with a small piece of wood on a beach, Norfolk, England, UK. December.

Brian Bevan / Grey seal (Halichoerus grypus) pup trying to suckle, Norfolk, England, UK, January.

Peter Bassett / Male Southern elephant seal (Mirounga leonina) shifting position on a beach, surrounded by females, almost crushing a pup, Gold Harbour, South Georgia.Gold Harbour, South Georgia.

SCOTLAND: The Big Picture / Grey seals (Halochoerus grypus) hauled out along the banks of the Ythan Estuary, agiatated, Aberdeenshire, Scotland, UK, February.

Frederique Olivier / Close-up of a dominant male Southern elephant seal (Mirounga leonina) calling, Macquarie Island, Sub-Antarctic Australia.

Ingo Arndt / Harp seal (Phoca groenlandicus) pup on sea ice looking down into icy water, Magdalen Islands, Gulf of St Lawrence, Quebec, Canada, March.

Ingo Arndt / Harp seal (Phoca groenlandicus) pup sleeping on sea ice, Magdalen Islands, Gulf of St Lawrence, Quebec, Canada, March.

Nick Upton / Grey seal (Halichoerus grypus) pup aged one month, rubbing its head with its flipper, yawning and settling down to rest on a sandy beach, Norfolk, England, UK, January.

Eric Baccega / Female Harp seal (Phoca groenlandicus) surfacing at breathing hole looking at her pup, Magdalen Islands, Gulf of St Lawrence, Quebec, Canada, March.

Alex Mustard / Grey seal (Halichoerus grypus) split level of young seal investigating the camera with its nose and whiskers, close to shore. Lundy Island, Devon, UK, Bristol Channel. August

Alex Mustard / Grey seal (Halichoerus grypus) young female opens her mouth and blows bubbles through her nose playfully while she looks up from the seabed. Lundy Island, Devon, UK, Bristol Channel. August. Highly co...

Alex Mustard / Grey seal (Halichoerus grypus) young seal silhouetted against the sun as it dives after breathing, Lundy Island, Devon, UK, Bristol Channel, August

Alex Mustard / Grey seal (Halichoerus grypus) playful young seal above a kelp forest. Lundy Island, Devon, UK Bristol Channel, August

Alex Mustard / Grey seal (Halichoerus grypus) split level view of young investigating camera lens, Lundy Island, Devon, UK, Bristol Channel, August

SCOTLAND: The Big Picture / Grey seal (Halichoerus grypus) swimming towards camera, Orkney, Scotland, UK, August.

SCOTLAND: The Big Picture / Grey seal (Halichoerus grypus) swimming over kelp forest, Shetland, Scotland, UK, August.

Alex Mustard / Harbour seal (Phoca vitulina) in the kelp forest (Macrocystis pyrifera). Santa Barbara Island, Channel Islands. Los Angeles, California, United States of America. North East Pacific Ocean.

Nick Upton / Rescued Grey seal pup (Halichoerus grypus) in a convalescence pool where it will be kept until strong enough to be released back to the sea, Cornish Seal Sanctuary, Gweek, Cornwall, UK, January.

Nick Upton / Blind adult male Grey seal (Halichoerus grypus) 'Marlin' waving a flipper at the edge of a convalescence pool where he is a long-term resident, Cornish Seal Sanctuary, Gweek, Cornwall, UK, January. Mo...

Nick Upton / Adult female Common / Harbour seal (Phoca vitulina) 'Sija' waving a flipper in a pool where she is a long-term resident, Cornish Seal Sanctuary, Gweek, Cornwall, UK, January.

Gerrit Vyn / Spotted seal (Phoca largha) pup resting on a the gravel beach of the Bering Sea. Chukotka, Russia. July.

Alex Mustard / Portrait of Common seal (Phoca vitulina) at the surface, Brancaster Beach, North Norfolk, England, Great Britain, December.

Staffan Widstrand / Bearded seal (Erignathus barbatus) hauled out on ice, Spitsbergen, Svalbard, Norway, September.

Roland Seitre / Blackish cinclodes (Cinclode fuligineux) on beach with Southern Elephant-Seal (Mirounga leonina). This species feeds on dead skin of the seal. Falklands Islands.

Ole Jorgen Liodden / Bearded seal (Erignathus barbatus) hauled out on ice, Spitsbergen, Svalbard, Norway, July.

Doug Perrine / Mediterranean monk seal (Monachus monachus) adult male swimming, Deserta Grande, Ilhas Desertas, Parque Natural da Madeira, Portugal, Atlantic Ocean, June. Critically endangered species

Chris & Monique Fallows / King penguin (Aptenodytes patagonicus) and Southern elephant seal (Mirounga leonina) colony at sunrise. Grytviken, South Georgia Island.

Olga Kamenskaya / Baikal seals (Pusa sibirica) hauled out on rock. Endemic to Lake Baikal. Russia, May.

Olga Kamenskaya / Young Baikal seal (Pusa sibirica) at breathing hole. Lake Baikal, Russia, April.

Olga Kamenskaya / Young Baikal seal (Pusa sibirica) at breathing hole. Lake Baikal, Russia, April.

Doug Perrine / Female Hawaiian monk seal (Monachus schauinslandi) defending her pup from two males, which are aggressive with each other, Molokai Island, Hawaii, USA.

Doug Perrine / Female Hawaiian monk seal (Monachus schauinslandi) fighting with a male trying to mate with her, Molokai Island, Hawaii, USA.

Nick Upton / Grey seal (Halichoerus grypus) pup resting on a sandy beach, stretching and rubbing its head with its flipper, Norfolk, England, UK, January.

Roy Mangersnes / Bearded seal (Erignathus barbatus) stretching flipper, on an ice floe, Spitsbergen, Svalbard, Norway, July.

Andy Trowbridge / Grey Seal (Halichoerus grypus) at rest on submerged rock, head and one flipper above water. Shetland Islands, Scotland, UK. July.

Andy Trowbridge / Common / Harbour seal (Phoca vitulina) looking out of water with bee hovering above its nose. Shetland Islands, Scotland, UK, July.

Ernie Janes / Boat full of people watching Common Seals (Phoca vitulina) on sand bank at Blakeney Point, Norfolk, August 2013.

Ben Cranke,Ben Cranke / Leopard seal (Hydrurga leptonyx) hunting Gentoo Penguin (Pygoscelis papua) into shore, Cuverville Island, Antarctic Peninsula, Antarctica

Ben Cranke / Leopard seal (Hydrurga leptonyx) chasing Gentoo Penguin (Pygoscelis papua) into shore, Cuverville Island, Antarctic Peninsula, Antarctica

David Tipling / Visitors viewing Grey Seal colony at Winterton Dunes, Norfolk, December 2010

Benjamin Barthelemy / Common seal (Phoca vitulina) pup hauled out on a beach at sunrise, Donna Nook Lincolnshire Wildlife Trust Reserve, Lincolnshire, England, UK, January.

Benjamin Barthelemy,Benjamin Barthelemy / Grey seal (Halichoerus grypus) hauled out on a beach at sunrise, Donna Nook Lincolnshire Wildlife Trust Reserve, Lincolnshire, England, UK, January.

Pascal Kobeh / Group of Grey seals (Halichoerus grypus grypus) resting on a rock around Bonaventure Island, Gulf of Saint Lawrence, Canada

Pascal Kobeh / Atlantic / American lobster (Homarus americanus) with a Grey seal (Halichoerus grypus ) swimming in the background, Gulf of Saint Lawrence, Canada

Pascal Kobeh / Grey seal (Halichoerus grypus grypus) underwater, Gulf of Saint Lawrence, Canada

Edwin Giesbers / Grey seal (Halichoerus grypus) male and female, mating behaviour, Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus) male and female, mating behaviour, Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus) hauled out on beach. Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus) hauled out by lighthouse, Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus) in water. Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus) in water. Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus), mother with suckling pup. Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus), mother playing with pup, Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus), pup on beach, Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus), male and female mating on beach. Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus),female giving birth, Heligoland, Germany.

Edwin Giesbers / Grey seal (Halichoerus grypus), mother with newborn pup, Heligoland, Germany.