Sky-high toxic levels found in dead orca

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Sky-high toxic levels found in dead orca

05/07/2002

Reported by , KING 5 News

SEATTLE - It was a mystery why a female orca was found beached on the

Olympic Peninsula last January. Scientists hoped to find out by hauling her

ashore and taking tissue and organ samples for detailed lab work.

Four months later, the tests yielded troubling results: The dead orca was

highly contaminated with toxic chemicals. She was so full of contaminants -

polychlorinated biphenyls - that the levels were off the charts.

" What we found were high levels of PCB's, some of the highest levels we've

measured here in our lab, " said Stein, National Marine Fisheries

Service.

KING

The female orca was found beached on the Olympic Peninsula last January.

The 22-foot-long female " basically knocked our instruments off, " said

Ylitalo, a researcher for the National Marine Fisheries Service, told a

seminar here last week.

The instruments, once recalibrated, found concentrations of about 1,000

parts PCB per million parts of fat, dozens of times higher than those known

to affect the growth, reproduction and immune systems of harbor seals.

The toxin's effect on orcas isn't as well understood, but researchers

believe they are affected in much the same way.

The Dungeness Spit orca's levels surprised even scientists who are familiar

with orcas' PCB burdens, and raises new concerns about pollution of West

Coast marine waters.

There were no obvious signs of disease, and scientists are still not sure

what killed the orca.

PCBs, banned in 1977, were once used widely as coolants and lubricants for

electrical equipment. Because they persist a long time without breaking

down, PCBs have been found even in remote Arctic locations rarely visited by

people.

The high levels in marine mammals here are worrisome.

" We're trying to figure out where these darn PCBs are coming from, " said

Ross, a marine mammal toxicologist with the Canadian government's

Institute of Ocean Sciences in Sidney, British Columbia.

" Puget Sound is a PCB hot spot in the regional environment. " PCBs dumped in

the sound years ago apparently continue to enter the food chain, Ross said.

Studies indicate adult female orcas may transfer up to 90 percent of their

PCBs and other contaminants to the first-born calf, in the womb and in milk.

It is unclear whether the dead orca had reproduced, and " with levels that

high, we wonder if she was able to reproduce, " Ylitalo said.

PCBs weren't the only contaminants found, said Stein, director of the

environmental conservation division of NMFS's Northwest Fisheries Science

Center. " This animal had contaminants we did not expect, " he said, including

some related to pesticides.

Contaminants start out at the bottom of the food chain, in microscopic

plants and animals that are eaten by larger animals.

The Dungeness Spit whale was a " transient " that lived on the Pacific coast,

eating seals, porpoises and other marine mammals.

The " resident " killer whales that return each year to Puget Sound and waters

around Vancouver Island primarily eat fish.

Toxins accumulate at higher levels in transient orcas because their prey is

higher up the food chain - and have absorbed more PCBs - than the fish eaten

by resident whales.

Two years ago, Ross conducted the most comprehensive study of PCBs in orcas

to date. A pneumatic dart with a stainless-steel tip was used to take

samples of fat from orcas that swim in the coastal waters of Washington and

British Columbia.

His study found female transients averaged 58 parts per million and males

251 parts per million - among the highest levels measured in marine mammals

anywhere in the world.

Marine-mammal researcher Calambokidis of the Cascadia Research

Collective said 1,000 parts per million would rank among the highest PCB

levels measured in orcas.

It's possible that killer whales tested several decades ago might have

registered a higher level, Ross said, but comparison is problematic because

contaminant-analysis methods have changed.

Unlike most marine mammals that die and are tested for contamination, the

Dungeness Spit orca appeared to have a healthy diet and had recently eaten

three harbor seals.

Most marine mammals found dead appear emaciated, indicating they were

burning off their own fat to stay alive - a practice that leaves a higher

proportion of contaminants in the fat remaining.

Still, " 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.

" We have spoiled our own backyard particularly badly. It's time that we

start studying the problems and start cleaning them up, " said Fred Felleman,

Orca Conservancy.

Chemical contamination may be one reason why Puget Sound's resident orcas

are in serious decline. In spite of the rest results, scientists say it's

still impossible to say why this orca died.

The Associated Press contributed to this report.