No dead grey whales have washed up along British Columbia’s shoreline so far this year but the number of new calves making the long journey north with their mothers continues to drop.
Low birth rates and higher than usual numbers of deaths and strandings in recent years have prompted researchers to closely watch the population of grey whales, which pass by Vancouver Island on their annual migration north from Baja, Mexico, to the Bering and Chukchi seas.
Last year, 15 boxcar-sized corpses of starving whales turned up in British Columbia, out of 300 along the Pacific coast.
Grey whales are a popular draw for whale-watching firms on Vancouver Island, as well as in the United States.
In spite of past deaths, the population remains healthy at about 26,000 animals, however, counters have spotted 87 new calves, the lowest number seen in eight years of surveys, said Wayne Perryman, biologist with the National Marine Fisheries Services in La Jolla, Calif.
The California count wrapped up last week.
The total number of new calves is estimated at between 255 to 265.
Not all the new ones are seen by spotters, who watch for the calves only during daylight and do not count on Sundays.
Last year, Perryman figured there were 279 calves and in 1999 when there were 428. Those numbers are far below 1997 when 1,520 new calves appeared.
“Reproduction has been down for three consecutive years for this population,” he said.
Theories about what is affecting the population includes the possibility there is less food in their northern feeding grounds, leading to less-healthy animals.
Grey whales eat tiny crustaceans such as amphipods.
Perryman believes there’s a link between the amount of ice in the feeding grounds and the calving rate.
The ice has been slow to recede in the last three years and in the years when that happens, fewer calves are born, he said.
He also agrees that other factors, such as less available prey, may affect the whales.
“Give us another five or six years, then hopefully we can figure this out,” he said.
(The Victoria Times Colonist, Victoria, B.C.) *****