Beaufort beluga population strong
by Glenn Taylor
INUVIK (Nov 03/97) - Research on the mysterious beluga whale is yielding exciting answers to puzzling questions.
Where do the whales winter? How many are there? How deep can they dive? These and other questions now have answers, thanks to radio tagging programs.
Researchers now believe the Beaufort Sea population might be as high as 80,000, or quadruple 1992 estimates.
A 1992 aerial survey by Fisheries and Oceans counted 20,000 whales on the surface, according to Lois Harwood, stock assessment biologist in Inuvik.
Radio-tag monitoring reveals that the whales spend much more time beneath the waves than earlier thought, diving as deep as 1,200 feet. "If we counted 20,000 on the surface, we now think that means 30,000 more were hidden from the count," travelling underwater, said Harwood.
Another stunning revelation: many of the male whales -- perhaps 30,000 -- leave the coastal Beaufort during the summer, travelling as far north as the permanent ice pack between the Arctic islands. The females stay behind, perhaps because young calves cannot make the journey, said Harwood.
Those whales weren't counted in 1992 because researchers had no idea the whales occupied these areas. Tagged males travelling into the area smashed that conception.
Ten whales were tagged at Henrickson Island this summer, in a project sponsored by Inuvialuit hunters, the Fisheries Joint Management Committee, the department and a number of international researchers.
Since then, researchers from around the world have been monitoring the whales via satellite, tracking the whales' migrational patterns, diving depths and frequency of dives.
Researchers now know for the first time where the whales go during the winter. All of the tagged whales are currently wintering near Wrangel Island in Siberia, on the Russian coast.
"This is partial answer to the question: Where do they overwinter?" said Joey Amos, an Inuvialuit from Inuvik who took part in the program. "It appears that they do overwinter in the Bering Sea, but more information will qualify that assumption."
Pierre Richard, a marine biologist with the arctic research division of the Department of Fisheries and Oceans in Winnipeg, was surprised to learn how deep the whales can dive.
At crushing depths of 1,200 feet, the whales should be suffering from the effects of the "bends," a condition caused by nitrogen in the blood forming painful gas bubbles that can kill.
Richard said the whales presumably get around this problem by travelling very slowly to the surface on their return, safely cancelling the effects of the bends. "They have no compressible parts, because they exhale all their air before diving," said Richard. Why do the whales dive so deep? Richard said the whales depend on their sense of hearing to navigate. At such depths, whales can hear farther than at the surface, much like a person standing on a hill can see farther.
The herd is very healthy, said Harwood. The whales are reproducing later in life, at about three to four years. In endangered stocks, animals breed much earlier. "They're taking reproduction at a leisurely pace," said Harwood.