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The tourist photographs and the scientific text tell different stories.
In the text, those same killer whales are contaminated, laden with toxic chemicals, at risk for disease. They may be the very symbol of a world spoiled by human pollutants. "These killer whales can now be considered among the most contaminated marine mammals in the world," said Dr. Peter Ross, research scientist with the Institute of Ocean Sciences in Sidney, B.C., and lead author of a new study titled "High PCB Concentrations in Free-Ranging Pacific Killer Whales, Orcinus orca." Whale researchers, puzzled by recent declines in orca populations, describe the findings as troubling and scary. "We have very toxic chemicals here. This should be a wake-up call," Rich Osborne, science curator at the Whale Museum on San Juan Island, told the Seattle Post-Intelligencer in a recent story. "It may take orcas . . . dying for people to finally get it." Researchers used a pneumatic dart with a stainless steel tip - 6.4 mm in diameter - to sample 47 killer whales that swim the inland and coastal waters around Washington and British Columbia. These include the ocean-cruising transient whales that prey on seals and other marine mammals and the southern and northern families of orcas that dine almost exclusively on fish - preferably the "king" of the salmon, the chinook. All 47 orcas were known individuals, exhaustively documented through observation and photo catalogs. Analysis of blubber samples revealed what Ross terms "disturbingly" high concentrations of PCBs in all the groups. Most contaminated were the high-seas transients and the celebrated southern "J," "K" and "L" pods beloved by Washington whale-watchers. But with jaws dropped and cameras clicking, few of the orca lovers have a clue that these celebrities of the cetacean world may be in danger. PCBs do not cause outright death. But extensive laboratory animal experiments and captive feeding studies of seals show contaminants can weaken immune systems, hamper reproduction and cause skin disorders and subtle changes in physiology. Scientists have noted tumors, skeletal abnormalities, disease and reproductive problems in the contaminated beluga whales on Canada's St. Lawrence estuary, which drains the heavily industrialized Great Lakes. And the Northwest killer whales, Ross said, are four to five times more polluted than those belugas. |
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