VICTORIA, Canada — The orca is a master predator. He glides like a torpedo, his 6-foot dorsal fin slicing through the surface of the sea. He hunts down a seal, rams it repeatedly with his tail and drowns it.
These wolves of the sea stand unrivaled at the top of the food web. But their rank in the ocean's hierarchy has given them another extraordinary--and perilous--distinction:
They appear to be the most contaminated animals on Earth.
The concentrations of industrial chemicals in orcas, or killer whales, off Washington state and Vancouver Island are the highest found in any living mammal, according to marine scientists. The poisons, subtle but insidious, have built up in their bodies to dangerously high levels.
Stars of Hollywood films and marine amusement parks, these black-and-white creatures are icons of the Pacific Northwest and British Columbia. On a typical summer day, hundreds of tourists and boaters set sail in hopes of spotting them.
Lately, though, there have been more whale-watching vessels than whales plying the picturesque waters between Seattle and Victoria.
The region's famed orca pods are shrinking. Government officials now say there is a strong chance that these descendants of Shamu, revered in native mythology as supernatural in their survival skills, could be named an endangered species.
The region's killer whales have been dying at a higher rate in the last five years, most disappearing without a trace. Nearly half of their calves die within months of their births.
Scientists wonder if the industrial poisons accumulating in their bodies are beginning to take a toll on their survival, impairing their ability to fight disease and to reproduce successfully.
Or perhaps the Pacific Northwest's whales, surrounded by nature lovers in yachts, kayaks and motorboats, are falling victim to the stresses of their own popularity. The decline in salmon--a diet staple for many orca pods--also may be harming them. Most likely, scientists say, the orcas are being harmed by a combination of the urban threats they face.
Because a generation of orcas spans 10 to 15 years, researchers warn that it is too early to tell whether the recent population decline is a temporary dip or a worrisome trend. In fact, this winter showed a promising development: three new calves, bringing the total population of the resident pods that frequent the San Juan Islands to 84.
