Pollution In Pacific
Threatening Killer Whales
VANCOUVER - A new study shows that many of the killer whales living
off the coast of British Columbia are loaded with high levels of PCBs, the toxic chemicals that may be killing them off.
"Killer whales in British Columbia can now be considered among the most contaminated animals in the world," says Dr. Peter Ross, of the Institute of Ocean Sciences. "This is a wake-up call for British Columbians and other Canadians."
The whales' problem, says scientists, is that they're at the top of the food chain. Pollutants like PCBs accumulate in fish, and when whales eat the fish, the chemicals accumulate in their fat cells. What scientists don't know yet is exactly what impact that has.
Dr. John Ford of Vancouver Aquarium says researchers have already seen declines in some populations but don't have enough evidence to make the link directly to high levels of PCBs.
"We don't know if this is a long-term trend and, if it is a trend, whether it can be attributed to these PCBs," Ford says. "We don't know enough about their interaction with the immune systems of these animals and their general health."
One pod that's causing concern is at the southern end of Vancouver Island, where the population numbers have fallen 15 per cent in five years. It's not clear why.
All the researchers know for sure is that PCBs are highly toxic and the orcas are full of them.