David Attenborough catalogues life beneath the ocean waves. All manner of spectacular lifeforms dwell deep underwater, from alien monsters to pack-hunting killer whales.
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. Only in spring, 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. But it is a brief respite, for the ice soon returns.
Sunlight is the vital source of energy used by the countless billions of plankton which live in the world's temperate sea. Forests of giant kelp harbour thousands of animals. Sharks, sea otters, brilliantly coloured anemones, squid and exquisite leafy dragons are just a few of the other creatures that live in this cool, rich water.
