A sleek blue shark (Prionace glauca) cruises through the cold waters off Cape Cod, Massachusetts, in the Atlantic Ocean. These beautiful elasmobranchs are found throughout the world in both temperate and tropical seas and are a species listed as Near Thre

Northern sea lions (Eumetopias jubatus) hauled out on South Marble Island in Glacier Bay National Park, UNESCO World Heritage Site, Alaska, United States of America, North America

Bull southern elephant seal (Mirounga leonina) on South Georgia Island, Southern Ocean

Chinstrap penguin (Pygoscelis antarctica) porpoising in Cooper Bay, South Georgia

Gathering of at least two resident pods of killer whales (Orcinus orca) encountered near sunset, Johnstone Strait, British Columbia, Canada

Adult bearded seal (Erignathus barbatus) swimming amongst the ice in the Svalbard Archipelago, Norway

Adult black-legged kittiwakes (Rissa tridactyla) on ice in the Svalbard Archipelago, Barents Sea, Norway

Group of at least eight killer whales (Orcinus orca) surfacing off the coast of the island of Surtsey, southern Iceland

Humpback whale (Megaptera novaeangliae) surfacing in the Weddell Sea near the Antarctic Peninsula, Antarctica, Polar Regions

Bull southern elephant seal (Mirounga leonina) on South Georgia Island, Southern Ocean

Chinstrap penguin (Pygoscelis antarctica) porpoising in Cooper Bay, South Georgia

Adult male hooded seal (Cystophora cristata) hauled out on pack-ice in seasof Denmark Strait, between Iceland and Greenland

A sleek blue shark (Prionace glauca) cruises through the cold waters off Cape Cod, Massachusetts, in the Atlantic Ocean. These beautiful elasmobranchs are found throughout the world in both temperate and tropical seas and are a species listed as Near Thre

A sleek blue shark (Prionace glauca) cruises through the cold waters off Cape Cod, Massachusetts, in the Atlantic Ocean. These beautiful elasmobranchs are found throughout the world in both temperate and tropical seas and are a species listed as Near Thre

Juvenile humpback whale (Megaptera novaeangliae) breaching near the Antarctic Peninsula, Antarctica, Polar Regions

Adult polar bear (Ursus maritimus) in Holmabukta on the northwest coast of Spitsbergen in the Svalbard Archipelago, Norway

Adult polar bear (Ursus maritimus), on multi-year ice floes off the coast of Edgeoya, Svalbard, Norway

Mother Polar Bear (ursus maritimus) with cub shaking off water halo on rocky cliff in sub-arctic Wager Bay near Hudson Bay, Churchill area, Manitoba, Northern Canada

Two beadlet anemones, one a brilliant red colour, in a rockpool with the water line visible and sunset in the background.

A Lion's mane jellyfish (Cyanea capillata) swimming through black water.

Lion's mane jellyfish (Cyanea capillata) with tentacles retracted showing it's huge flowing underside, underneath sunlight penetrating the water in Inverclyde, Scotland.

Sunlight streaming through a forest of giant kelp (Macrocystis pyrifera), off Santa Barbara Island, California, United States of America

California, Giant kelp frond showing pneumatocysts (Macrocystis pyrifera) Catalina Island, Channel Islands National Marine Sanctuary.

(Mnemiopsis leidyi), the warty comb jelly or sea walnut. Only in springtime, when the hard winter slowly subsides, are the ice-cold waters suitable for divers who can dive around a iceberg that floats in crystal-clear water, Tasiilaq, East Greenland

(Mnemiopsis leidyi), the warty comb jelly or sea walnut. Only in springtime, when the hard winter slowly subsides, are the ice-cold waters suitable for divers who can dive around a iceberg that floats in crystal-clear water, Tasiilaq, East Greenland

Fishing jewellery. Common Kingfisher (Alcedo atthis) fishing in a very cold morning. Slovakia

Gentoo penguin (Pygoscelis papua). walking on ice at Cuverville Island, Antarctic Peninsula, Antarctica

Group of Gentoo penguin (Pygoscelis papua). walking in between ice at Cuverville Island, Antarctic Peninsula, Antarctica

Kingfisher (Alcedo atthis) at rest at dawn, Slovakia

Goose. Greylag Goose (Anser anser) eating. Slovakia