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Victoria: Orcas under attack
By Tara Carman Every year, tens of thousands of people in Victoria pay upward of $60 each to catch a glimpse of one of B.C.'s most majestic and unique natural phenomena - the killer whale. No symbol resonates so profoundly with coastal British Columbians. Proof can be found on the streets of downtown Victoria - now featuring brightly-painted replicas of the mammal. The orca has figured prominently in Haida spirituality and artwork for centuries and today forms the logo of the Vancouver Canucks.
Yet, this much-revered animal is now among the most polluted mammals in the world. A 2000 Institute of Ocean Sciences study found that PCB levels in these orcas are almost five times the level considered by Environment Canada to be toxic waste. New evidence suggests that what we're pouring into the ocean is to blame.
As any seasoned whale-watcher will
attest, May through August is the best time to see killer whales. This
is when the three resident pods of orcas spend the most time in the
waters off Victoria and the San Juan Islands. So what is really happening to these whales? The southern resident community, the technical name for the group of orcas that frequent the waters around southern Vancouver Island, is only just beginning to recover after a sharp drop in numbers that had ecologists fearful for their survival. According to Fisheries and Oceans Canada, the population fell from to 78 whales in 2001 from 99 in 1996 . The most recent count is 83 animals. A 2004 report by Fisheries and Oceans Canada warns that the millions of kilograms of pesticides consumed each year by British Columbians could be harming these animals. Dr. Peter Ross of the Institute of Ocean Scientists co-authored the study, which shows that between 1991 and 1999, the quantity of pesticides sold or used in B.C. increased by 19 per cent to more than eight million kilograms per year. That's in addition to the chemicals seeping into the whales' habitat from Puget Sound. Ross says that PCB contamination is still a major concern despite the fact that the chemicals were banned in Canada in the 1970s. PCBs were once widely used in industry, and thought to be wonder chemicals because of their resilience. But they are toxic, and can persist in ecosystems for decades.
"We're being haunted by the mistakes of
our past," Ross said in a telephone interview. Transient orcas are genetically distinct from residents, and only occasionally pass by Vancouver Island. Contamination levels are higher in transients because they feed on marine mammals. Resident male orcas, salmon-eaters, contained on average 145 ppm. The levels were lower in females, who pass the chemicals on to their offspring through their milk. These levels are higher than those found in the belugas of the St. Lawrence. "The southern resident and transient killer whales of British Columbia can now be considered among the most contaminated cetaceans in the world," the report said. PCBs are still used in some parts of the world. It only takes five to 10 days for an airborne pollutant to travel from East Asia to the B.C. coastline, Ross said. Since orcas are at the top of the marine food chain, they provide telling indicators of the toxin levels in the environment, said Ross. "I use marine mammals as sentinels to provide me with an amplified signal for environmental contaminants that are persistent, accumulate in food chains and are toxic," he said. He added that long-term exposure to such chemicals can result in reproductive impairment, decreased immunity to disease, and skeletal and neurological abnormalities. The 2004 study lists 23 chemicals, mainly pesticides, that Ross says fit his above three conditions, and could have effects similar to those of PCBs. One of the most common is 2,4-D, which kills dandelions. And use of these chemicals is on the rise. "We should have learned the lesson from PCBs," said Ross. "There's an accumulation of scientific studies that say these [23] chemicals may well be harmful for marine mammals as well." Ross points out that environmental policies limiting the use of harmful chemicals and the collective action of concerned citizens have made a big difference in reducing pollution. But habitat contamination, he adds, is just one of several potential threats to the orcas. Hunting and communication can be disrupted by boat engines or military sonar. The abundance and health of the orcas' main prey, salmon, must also be considered. "Every way we look at these animals, they're under seeming assault," Ross said. The federal Department of Fisheries and Oceans is responsible for the stewardship of marine mammals, and has initiated a killer whale recovery plan for the southern resident orcas. Ministry spokeswoman Lara Sloan says the group is conducting research and consultations with local communities and experts to determine what is critical habitat and what policies can be put in place to protect the whales. A report is expected in the fall. © Copyright 2004 Victoria Weekend Edition |
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