5,400-kilometre trip made by orca

One of two orcas fitted with a satellite tracker in the Arctic, made a remarkable 5,400-kilometre journey in just a month. The whale swam from northern Baffin Island, down past Greenland, Labrador and Newfoundland, and headed for the Azores in the mid-Atlantic. The report on the whale's travels is published in the current issue of Polar Biology.

It's long been known that orcas move around, but it's the first study to document such a rapid, long-distance swim as well as providing new clues about the whales, which appear to be showing up in Canada's Arctic in increasing numbers, feasting on belugas and narwhals and huge bowhead whales. The researchers found a large group of 20 killer whales just off shore and got satellite trackers onto two of the orcas before they disappeared. The devices, about the size of cellphones, were attached by darts near the whales' distinctive dorsal fins. One of the trackers stopped working within days, but the other one lasted three months, emitting up to 300 electronic signals a day when the whale surfaced. The signals were picked up by the Argos tracking system, which uses satellites 850 kilometres above the Earth to follow everything from sea turtles to fishing vessels.

After returning to Winnipeg, researchers checked on the orca's whereabouts simply by logging into the satellite tracking system by computer. They watched as the whale foraged in the waters northwest of Baffin Island until the temperatures began to plunge in early October. Then, as ice began to form in waters at Lancaster Sound, the orca took a decisive turn south, cruising down Baffin Bay past Greenland and along the coast of Labrador and Newfoundland, hitting a top speed of 252 kilometres a day. When the orca was about 500 kilometres from the Azores, the signal stopped, bringing an abrupt end to an astounding scientific event. It is not known if the entire group of 20 Arctic orcas made the same trip, but The Arctic-to-Azores trip is believed to be the first documented case of an orca travelling so far in such a short period of time, suggesting these whales have a large range in the Atlantic.

The increase in orca sightings appear to be related to the way the Arctic ice has been retreating in recent years, because orcas tend to steer clear of thick ice, however while climate change is a prime suspect, the increasing number of orcas in the Arctic may be related to the way bowheads have rebounded since the end of commercial whaling. Whatever it is, the trip made by the orcas is truly remarkable!

Orcas on the Pacific coast are also known to make long journeys, with reports of them swimming from Alaska to California.