Tuesday, June 22, 1999

Underwater sounds
called harmless

By Helen Altonn


Researchers want to continue an underwater sound project off Kauai that they say has proven harmless to marine mammals and valuable to science.

They plan to seek approval to operate the Acoustic Thermometry of Ocean Climate program for five years.

When ATOC was first proposed five years ago, environmental groups protested that the noise would hurt marine animals.

Marine mammal studies were done as part of the project, which involved generating low-frequency booming sounds from loudspeakers off Kauai and California.

There may still be some opposition to the project, said Joe Mobley, lead scientist for the University of Hawaii part of the marine mammal research program.

"The difference now is we can come forward with five years of data we didn't have back in '93," he said.

A psychology professor who is now acting chancellor of University of Hawaii-West Oahu, Mobley said he just submitted his final report for an aerial survey portion of the research.

"When you look at the sum total of all the evidence, it is pretty clear there was no major effect on marine mammals studied, whether in California or here at Kauai," he said.

Temperatures tracked

ATOC's purpose is to monitor ocean temperature changes that may be associated with global warming and other changes in the Earth's climate.

Peter Worcester, principal ATOC investigator at Scripps Institution of Oceanography in La Jolla, Calif., said in a telephone interview that the first phase involved two key issues:

"How precisely could these acoustic methods be used to make large-scale temperature measurements? And could it be done without harming marine mammals," he said.

Response to both questions was "very favorable," he said.

Listening devices around the Pacific recorded how fast sounds traveled from amplifiers 3,000 feet below the ocean's surface. That indicated water temperature because sound travels faster in warmer water.

Worcester said they were able to measure large-scale temperature changes even more accurately than they anticipated and effects on marine mammals were not significant biologically.

Meetings scheduled

The Office of Naval Research is preparing an environmental impact statement for the second phase of research, Worcester said.

Speaking here at a series of environmental impact statement-scoping meetings for the project June 29-30 and July 1 will be noted Scripps oceanographer Walter Munk, who conceived the ATOC experiment; Adam Frankel of Cornell University, with the marine mammal research program; and Worcester and Mobley.

"I still see it as a feasibility study but with the goal of getting enough data to see if this data is as useful as we think it will be," Wor-cester said.

He said the scientists hope to gain a better understanding of the El Nino and La Nina phenomena, other changes in the North Pacific and how the planet's climate is changing.

"We think it's an important project," he said, pointing out it's a major effort to go through the EIS process and apply for permits required from the state Department of Land and Natural Resources and National Marine Fisheries Services. "So we have to feel it's worthwhile or we wouldn't go through the review process."

The Office of Naval Research will pay for the environmental impact statement process and provide some funding for the first two years, Worcester said.

Additional funding will be needed for three years but costs will be quite low, probably around $100,000 a year, since the cable and facilities for operating the sound source are in place, he said.

Generally, he said they will continue to transmit 190-decibel sounds, with one 20-minute transmission every four hours for one day out of four.

So far, so good

"What we've seen so far has been pretty exciting, given the limited data so far," he said. It was used to test a computer model of ocean circulation and sea surface height data from satellites.

Comparing the information, Worcester said the scientists found some revisions were needed in interpretation of satellite altimeter data to accurately reflect what was being seen.

Satellite altimeter data to a large extent was being interpreted as a measure of ocean temperature, he said. However, the researchers found ocean salinity and current changes also affected sea surface heights, Worcester said.

So simply interpreting a change in sea surface height as a sign of ocean warming "is misinterpreting a large part of what is going on," he said.

Whale population
is apparently growing
but dispute hinders study

By Helen Altonn


Three years of research on the Hawaiian humpback whale population ended up snarled in a controversy over an ocean bottom cable.

Joe Mobley, University of Hawaii-West Oahu psychology professor, had hoped to complete four seasons of research last year on the whales.

His studies over three previous seasons showed a 20 percent population increase from 1993 to 1995 and again from 1995 to 1998, he said.

"It was a little suspicious. I needed one more data point to determine if that's significant or not," he said. "If I had that, I could announce a significant increase over X number of years. It was really frustrating for me."

It was especially frustrating because $430,000 was available for the project, remaining from the Acoustical Thermometry of Ocean Climate experiments.

The money was supposed to be used to recover a 28-mile-long cable installed on the sea floor off Kauai for ATOC.

A Department of Land and Natural Resources permit issued for ATOC requires removal of the cable and the sound source by April 2000.

The Scripps Institution of Oceanography asked the department to modify the permit and leave the cable so the money could be used for research instead.

The land department said a supplemental environmental statement and a new permit would be needed to leave the cable.

"Nothing ever happened," Mobley said.

As it turned out, the Navy's Pacific Missile Range Facility at Barking Sands, Kauai, had installed a latticework of cables over the ATOC cable for a shallow water training range, he said.

"After all that controversy, we couldn't retrieve it. The Navy was not going to move its cables out of the way. If we'd only known that then, we could have presented it to the (land) board."

Peter Worcester, principal investigator for ATOC at Scripps in La Jolla, Calif., said the $430,000 will lapse at the end of this year.

Worcester is seeking a one-year extension of the funding, provided by the Department of Defense Strategic Environmental Research and Development Program, while an environmental impact statement is prepared to continue ATOC.

"We have to retain the funds to recover the cable as we're required to do should permission be denied for a continuing operation," Worcester said.

Mobley said, "The good news is we have the first population survey-based estimate for humpbacks." The population appears to average about 3,200 animals, he said.

He said the 20 percent increases are "kind of amazing" and he's "very cautious about it."

"We need to keep track to see what it means," he said.

"If we keep tracking Hawaiian humpbacks at least every other year, there's a good chance we might be able to get them off the endangered species list."

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