hursday, April 6, 2006

Orcas' habitat polluted by noise
Scientists study effect on animals

By ROBERT McCLURE
P-I REPORTER

Imagine someone coming to your neighborhood and repeatedly tooting his horn -- for half an hour or more.

That's pretty much what it sounded like Wednesday when scientists meeting in Seattle to explore threats to orcas played underwater recordings of a cargo ship's passage by an orca hangout. It wasn't quite as irritating as a car alarm -- but close.

At the center of the increased noise in the orcas' neighborhood is the shipping industry, which has the most constant and noisiest presence, researchers reported. And the noise appears ready to increase, with the Puget Sound region's international cargo trade set to soar.

"All right, already! They go on for a long time," acoustic scientist Val Veirs said as he cut off the hornlike sound after less than half a minute. He said the noise is generally audible for half an hour to an hour when a cargo ship passes by the San Juan Islands, where the orcas often are found, on its way to Seattle, Tacoma or Vancouver, B.C.

"We hear those kind of peculiar engine noises fairly often," he said in an interview. "Many of those big ships sound like they're falling apart. Many of them are very intense sounds."

Orcas, the signature mammal of the Pacific Northwest, were given protection under the Endangered Species Act last year by the National Marine Fisheries Service. The service organized this week's meeting of scientists to explore what to consider in protecting them.

Several scientists said noise is probably less threatening to orcas than toxic chemicals and the long-depressed runs of salmon, the orcas' main food. But noise pollution deserves a close look, they said -- particularly since orcas use sophisticated sound techniques to communicate and find salmon to eat

While scientists are still exploring how the sounds affect orcas, they have established that there is a lot of noise underwater. More boats mean more noise, and the number of shipping containers coming to Seattle and Tacoma by boat is expected to increase 250 percent by 2025.

"It's not just that there are more ships," said John Hildebrand, a Scripps Institution of Oceanography scientist. "The ships are individually more noisy. We know they are bigger, faster and more powerful engines."

Veirs said his recordings from beneath Haro Strait by the San Juan Islands, where the orcas are often found, show the sound is almost never below 100 decibels. Above the water's surface, a human would perceive that at about the same level as a Walkman radio turned up loud in one's ear.

In the summer, the everyday noise of commercial traffic is added to in the daytime by whale-watching boats and other craft, Veirs said. Displaying sound charts from summer days and summer nights, he told the scientists, "I think you can see a difference here, and the difference is all the ... boats zipping around, having a fine time."

Hildebrand said that when he was trying to measure sounds of whale-watching boats, "People (on motorboats) would roar up into the middle of our controlled experiment and say, 'Hey, man, where's the whales?' "

The commercial whale-watching fleet has grown exponentially in recent years, but operators say they are doing everything they can to cooperate in protecting orcas.

"We still don't know if noise has an impact (on orcas), but if it does, we want to err on the side of caution," said Shane Aggergaard, president of Whale Watch Operators Association Northwest. "Being aware of the amount of sound we're making and how we can minimize it is important to us as an industry."

The main representative of shippers in the Puget Sound region, the Pacific Merchant Shipping Association, stands ready to see what should be done, said Michael Moore, the association's Northwest representative.

"We're following the issue and figuring out what's the proper way to engage and participate," Moore said.

Researchers admit they don't know exactly how underwater sound affects orcas. One study presented this week showed orcas' vocalizations have grown longer in the presence of vessel noise in recent years. Another study found orcas dived longer, swam farther and expended more energy in the presence of boats -- but the differences weren't huge.

"It seems to me like we're jumping to the conclusion that high noise levels are going to impact them," Terry Williams of the Northwest Indian Fisheries Commission told the scientists. "Being able to translate that into how it affects their performance is what is needed, and I didn't see that."

But orca activist Fred Felleman, who earned his master's degree studying killer whales, said, "The thing to acknowledge is that whales are acoustic animals. We may not know what aspect of noise is important, but we do know the acoustic environment is critical to the welfare of the whales, and we're just now starting to pay attention to this."
P-I reporter M.L. Lyke contributed to this report. P-I reporter Robert McClure can be reached at 206-448-8092 or robertmcclure@seattlepi.com.