Your Province
Orcas' disappearance alarms scientists
Canadian, U.S. officials fear three endangered killer whales are dead
Ethan Baron, The Province
Published: Friday, October 20, 2006
The mysterious disappearances of orcas is alarming scientists on both sides of the border.
They fear three endangered orcas that have disappeared recently from B.C. and U.S. waters are dead.
Two other killer whales, from a less-threatened group in central and northern B.C., have vanished, and a third was killed in a collision with a boat.
The three "southern residents" -- all whales in the prime of life -- vanished this summer and fall.
"What's worrisome is . . . when we see animals disappearing prematurely," said John Ford, a research scientist for the federal Department of Fisheries and Oceans.
Researchers and whale-watching companies constantly monitor orcas off the Washington and B.C. coasts, so a missing whale is usually noticed quickly.
Twelve-year-old female K28, nicknamed Raven, left behind a nursing four-month-old calf that will die unless another nursing orca adopts it.
The three missing orcas -- Raven, 20-year-old Hugo (L71), and 34-year-old Jellyroll (L43) -- came from the K and L pods that ply the waters off southern B.C. and northern Washington.
"Individuals very, very rarely leave their group, and if they do, they're in almost all cases dead," Ford said.
Females live for an average of 50 years, while males typically make it to 30.
There are 87 southern residents, down from nearly 100 in the mid-1990s.
Two of the whales showed signs of possible starvation before they vanished, according to the Center for Whale Research in Washington state.
But Ford said wasted-looking whales could be suffering from an underlying disease.
In the "northern resident" group of about 200 orcas off the central and northern B.C. coast, three female killer whales in their prime have disappeared from three pods over the past year.
One, 12-year-old orca C21, was found floating dead July 18 near Prince Rupert, with massive bruising from an impact with a boat. That whale, along with missing whale G23, left behind a calf.
The other missing northern resident is A59, age 14.
"It's quite unusual for younger females to die," said Paul Spong, director of B.C.'s
OrcaLab research facility. "It raises a red flag."
A combination of factors threatens B.C.'s orcas, Ford said. Underwater noise and boat traffic are concerns, as is pollution. Killer whales' position at the top of the food chain means they accumulate persistent environmental toxins such as PCBs and flame-retardant PBDEs. Other mammals with lower levels of PCBs than killer whales have been found to suffer problems from the compounds.
Researchers in Washington believe toxins are making orcas more vulnerable to other problems such as inadequate food supply. Resident orcas feed heavily on chinook salmon, and although chinook counts appear typical, not everyone agrees there are plenty of salmon.
"If you talk to the fishermen, they're saying it was a horrible year," said Kelley Balcomb-Bartok, a research associate at the Center for Whale Research.
The southern residents are classified by the Canadian and U.S. governments as endangered.
Births last year raised hopes of a recovery for the population, Spong said.
"Now you have these disappearances, deaths, which sort of put things back on that declining path again," he said.