Coral Seas and Polar Seas

Don't miss these Blue Planet shows.

Coral Seas
Bathed in warm, clear tropical water and brilliant sunlight, coral reefs are the rain forests of the sea. Surrounded by desertlike expanses of ocean, they are rich oases of life. Spectacular numbers make it necessary to stand out to survive. This competition is highly visible as brightly colored fish compete for food, territory and mates. Watch these daily dramas unfold in stunning detail.

Polar Seas
Life on the edge of a frozen sea is tough. Pack ice at both poles is constantly on the move, and in winter freezes solid with air temperatures 158 degrees Fahrenheit (70 degrees Celsius) below freezing. Only in spring, with the retreating ice and waxing light reaching the water, does life begin again. Plankton blooms and feeds vast hordes of migrating fish, birds, whales, seals and polar bears. Walruses rake the seabed for clams. Minke and humpback whales gorge themselves on gigantic swarms of krill. But it is a brief indulgence, for the ice soon returns and pushes life back into the ocean.