Climate change pushing killer whales to migrate north

Paying no attention to nearby divers, a killer whale and her calf hunting for food frolic in a snowy Norwegian fjord.

Their favourite meal, herring, abounds, but climate change means both predator and prey must increasingly migrate further north.

The clear and calm waters of Reisafjorden, in Norway's Far North, have in recent years become the winter playground of the Scandinavian country's killer whale population.

At three degrees Celsius (37 Fahrenheit), the cold water is perfect for the herring which, ahead of the spawning season in February and March, have fattened up and make a tasty dish for the hungry killer whales, also known as orcas.

As if they were performing an underwater ballet, the whales encircle a school of herring, forcing them up to the surface before slapping the water with their large tail fins to stun them.

"Then they all share the feast," eating only the best parts of the fish: the eggs, meat and semen, explains Pierre Robert de Latour, founder of the organisation Undersea Soft Encounter Alliance, on board a whale-watching vessel.

"It's food that's easy to hunt, available in great quantities, and very high in calories," he says.

But in the past 20 years, the herring migrated 300 kilometres (190 miles) north, leaving the Lofoten Islands in search of waters that remain under six degrees Celsius -- the temperature required for them to reproduce.

(AFP)