Tracking White Whales in Canada’s Arctic

Like the igloo and inukshuk, white whales symbolize Canada’s Arctic. But belugas (Delphinapterus leucas) have also become a symbol of environmental sensitivity. At lower latitudes, the beluga population in the St. Lawrence River raised alarm when scientists found that their bodies were concentrating high levels of contaminants from the river. And in the Arctic, where commercial whalers took belugas and other whales for much of the 19th and 20th centuries, some populations have become endangered.

Protecting belugas requires understanding their biology and migrations. For 24 years, that’s been a goal of research scientist Pierre Richard, based in DFO’s Freshwater Institute at Winnipeg, in Manitoba. He has also researched narwhals, the famed Arctic marine mammal whose elongated tooth resembles a unicorn’s tusk, and walrus, still present in the Arctic after disappearing from the Gulf of St. Lawrence.

“Belugas are more abundant in nature than narwhals, but they’ve been a puzzle for researchers,” Pierre Richard says. “They spend most of their lives under the ice, far from human eyes.”

When parts of the Arctic ice cover open up in the summer, white whales occupy estuaries and nearshore waters. Such sightings left the impression that, in summer, they stuck to shallow coastal areas. But Pierre Richard’s research shows a more complex picture.

With the advent of satellite-linked radio tags around 1990, Pierre Richard, Jack Orr, and colleagues began using them to track belugas. Fastening the small transmitters to the large mammals, with adult males measuring up to 4.25 metres long and typically weighing more than half a tonne, was no simple matter. Technician Jack Orr of the Freshwater Institute found ways. Pierre Richard says that “Jack has become probably the world expert in live capture of Arctic cetaceans.”

To capture belugas, researchers can use nets 50-100 metres long, similar to fishermen’s gillnets, to entangle them. But that method can be dangerous for both whales and humans. Another way is for fast boats to surround them with a seine net suspended by float lines. Inuit hunters often man the boats; Pierre Richard and Jack Orr work closely with local people across the Arctic.

Beluga research has revealed unexpected migratory patterns.

But the best and friendliest method is for a few small boats to herd the whales into shallow waters. Jack Orr and helpers then bring their boat alongside a chosen beluga and slip a hoopnet – twine attached to a circular metal hoop with foam padding – over the whale’s head. In dry suits, the men jump into the water and loop a rope around the beluga’s tail. Thrashing at first, the whale quickly becomes passive and easy to work with.

Orr and helpers fasten the small satellite transmitter to the whale’s dorsal ridge with nylon pins. These cause no apparent discomfort, and eventually work their way loose. During that time, whenever the whale surfaces, the electronic tag reports the whale’s location and the depth of its dives.

“Belugas dive much deeper than people had thought,” Pierre Richard says, “at times to 800 metres or even a kilometre. Everything is dark down there. Whatever they’re eating, they find by echolocation, which is highly developed in belugas.”

Whales have other capacities geared for deepwater diving. They have twice as much blood as land animals of similar size, and more blood cells. They also can store more oxygen in their muscles. Consequently their store of oxygen is several times that of terrestrial mammals. They also have physiological adaptations to use the oxygen more efficiently while diving.

The satellite tags have shown much wider migrations than previously thought. Rather than sticking close to shore and to areas of open water and loose ice, belugas often travel under dense pack ice for hundreds of kilometres. Satellite monitoring also established that large numbers of beluga from the Beaufort Sea, in the western Arctic, migrate far west and south into the Bering Sea of the North Pacific. The illustration below shows primary migration routes for belugas in different regions.

Before satellite tagging, visual surveys of beluga populations suffered from lack of information about the whale’s behaviour. For every whale seen, how many others might be underwater? Satellite tags provided new data about the proportion of the beluga’s time spent in visible areas, allowing more accurate calculations.

All is not well for all Arctic beluga populations. The Cumberland Sound – southeast Baffin Island and Ungava Bay populations are both classified as endangered. Another is listed as “threatened.”

But there’s good news too. Satellite monitoring showed that some populations were more numerous than feared. Most stocks are stable or recovering. And Canada’s biggest beluga population, the 57,000 animals recently surveyed on the western coast of Hudson Bay (WHB), is in good shape. (Further information on beluga populations, prepared by Pierre Richard, appears at www.dfo-mpo.gc.ca/zone/under-sous_e.htm.)

Overall, despite many local concerns about belugas, this symbol of the Arctic remains healthy. Pierre Richard and colleagues are working to keep it that way.

Last updated : 2006-02-17

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