PLANET EARTH Shallow Seas

The humpbacks are nearing the end of their epic journeys. After two months and thousands of miles, they're entering the polar seas both in the north and the south. In the far north, winter is over at last and the ice is starting to melt. The Aleutian Island chain running west from Alaska is the gateway to the Bearing Sea. With the retreating ice, rough weather and ferocious currents stir up these shallow seas. And sunshine and the mix is spectacularly productive.



Five million shearwaters have flown almost ten thousand miles from Australia to get here. In all eighty million seabirds come here for the summer the greatest concentration to be found anywhere on Earth. The humpbacks have finally arrived. The giant shearwater flocks hunt the krill swarms sometimes diving to depths of forty meters to reach them.



A large humpback eats three tons of krill a day. The polar seas in summer are the most productive on the planet and the whales gorge themselves round the clock. The fat reserves they lay down now will keep them alive during the year to come but it may not always be this way. Fish and krill stocks are declining so rapidly that spectacles like this may soon be part of history.



Once the mother and calf have reached their feeding grounds, they will separate. With luck, the calf will make the epic journey across the oceans from equator to pole, another seventy times cruising back and forth between the shallow seas where life proliferates so abundantly on our planet.