DNA Tests Will Be Performed Upon Dead
Orca Calf Found In San Juans

Thursday, August 7, 2008
SAN JUAN ISLANDS, WASHINGTON - DNA tests are expected to show if the carcass of a prematurely born orca calf found in the San Juan Islands belonged to one of three resident orca pods that frequent B.C.'s coast during the annual salmon run.

Lance Barrett-Leonard, a marine mammal research scientist with the Vancouver Aquarium Marine Science Centre, said it is unlikely studies will be able to determine if the calf died of toxins because the carcass was badly decomposed.

"Unless the carcass is really fresh, it is tough to tell what the animal died of," he said.

But he noted that industrial contaminants such as PCBs are "one of the greatest risks the animals face." Although banned in the 1970s, PCBs continue to affect marine mammals and are known to interfere with their reproductive capabilities, often resulting in miscarriages. Being at the top of the food chain, killer whales often have high levels of such toxins in them.

While some toxins are slowly disappearing, Barrett-Leonard said there is a new generation of industrial toxins, such as fire retardants, that have taken their place. Nursing orcas often get a double dose of toxins because the mothers tend to off-load them in their milk.

But it's not just toxins, he said, that affect the endangered southern resident orca population. Low salmon stocks and human disturbance, such as boat traffic and sonar, have also contributed to their weak numbers, he said.

He said a thriving whale population would be at least 10 times the numerical strength of the southern resident orca population that numbers in the high 80s.

"The population isn't thriving, let us put it that way," he said. "They are doing quite poorly." The calf carcass was found in late July at Open Bay on Henry Island but wasn't reported until the beginning of this month.

Meanwhile, scientists at the Washington-based Center for Whale Research believe the oldest orca of the three southern pods has died. K7, known as Lummi, was the matriarch of K Pod and was believed to have been close to 100 years old.

Ken Balcomb, a senior scientist with the centre, said she was last seen in Puget Sound last December.

Her death won't be confirmed until a full year has passed since her last sighting.

Source: The Vancouver Province