Study Examines Sonar Effects On Whales
By MATTHEW FORDAHL
AP Science Writer
JUNE 22, 2000 - A powerful new sonar being tested by the Navy affects the length of humpback whale songs but doesn't seem to lead to any other extreme behaviors, according to a new study.
Scientists reported Thursday the low-frequency, high-range sonar used to detect submarines extended the mating songs of some humpbacks while others stopped singing altogether.
"We looked for any sorts of extreme responses like breaching, where the animal would jump out of the water and swim rapidly away from the sonar,'' said Patrick Miller, the study's lead author and a researcher at the Woods Hole Oceanographic Institution. "We didn't observe any sorts of extreme reactions.''
The new sonar has come under greater scrutiny after a biologist hired by the National Marine Fisheries Service suggested a possible link between Navy traditional sonar tests and ear hemorrhages that fatally disoriented the animals.
In March, at least 16 whales of four different species beached themselves in the Bahamas. Seven died, and initial autopsies suggested the deaths might have been linked to the Navy tests.
The latest research took place off Hawaii in 1998. Miller and his colleagues first recorded the whale songs without the sonar and later asked the Navy to transmit the signals.
Of the 16 whales monitored, five stopped singing altogether. The remainder sang on average 29 percent longer when the sonar was activated than without it. The findings appear in Thursday's issue of the journal Nature.
The research, sponsored by the Navy but conducted by independent scientists, said it wasn't clear how much of a threat the sonar and its effects on mating songs pose to whales.
The whales might just be compensating for the noise, Miller said. Still, he added, the Navy should avoid active breeding areas when using the new sonar.
"We need to take a commonsense approach to reducing how much animals are exposed to sound — not only Navy sonar but all the sounds in the ocean like shipping traffic, whale watching traffic, construction and underwater explosions,'' Miller said.
Humpback whales are known for their acrobatics and the underwater songs males use to attract mates. The endangered species received full protection from commercial whaling in 1966.
Animal-rights activists, some of whom had tried to stop the latest research by swimming near the test site, said the Nature study authors didn't do enough follow-up on the animals after the tests.
"They didn't look at results on fish or anything else,'' Benjamin White, of the Animal Welfare Institute, said Wednesday. "The whole study was based on the assumption that the effects would be immediate and obvious.''
Miller's research and other projects sponsored by the Navy will be used in an environmental impact statement of the new sonar expected to be released later this year, said Lt. Bill Speaks, a Navy spokesman.
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On the Net: The journal Nature: http://www.nature.com
Woods Hole Oceanographic Institution: http://www.whoi.edu
U.S. Navy: http://www.navy.mil
Animal Welfare Institute: http://www.animalwelfare.com
