Toxic Orca_Level of PCBs in whale raises alarm

It's possible that killer whales tested several decades ago might have registered a higher level, Ross said. But making such a comparison is problematic because contaminant-analysis methods have changed, he said.

One curious aspect of the Dungeness Spit orca is that, unlike

most marine mammals that die and are tested for contamination,

its body showed signs of a healthy diet. Most marine mammals

that are found dead appear emaciated.

That indicates those animals had been burning blubber to stay alive

.When they do this, most of the contaminants remain behind,

meaning that by the time they die there is a higher proportion of

contaminants to the fat remaining. The Dungeness Spit orca,

though, was fat. It had recently eaten three harbor seals.

And yet it still had a very high PCB level.

Norberg, the fisheries service marine mammal coordinator,

said the high PCB level found in the orca might not be indicative

of body burdens of transient orcas in general. "You're dealing with

an orca that is dead on the beach, and a lot of folks argue that that's

not representative of those that are out swimming around,"

Norberg said.

Orca advocate Fred Felleman, who attended the seminar last week

where the PCB readings were discussed, said efforts should be

redoubled to find out where the PCBs came from.

"The fact that killer whales could achieve those levels eating

exclusively in the ocean is a red alert that we need to take better care

of the ocean," Felleman said.