StudyExamines Sonar Effects On Whales
By MATTHEW FORDAHL
AP Science Writer
JUNE 22, 2000 - Apowerful new sonar being tested by the Navy affects the length of humpback whalesongs but doesn't seem to lead to any other extreme behaviors, according to anew study.
Scientists reported Thursday thelow-frequency, high-range sonar used to detect submarines extended the matingsongs of some humpbacks while others stopped singing altogether.
"Welooked for any sorts of extreme responses like breaching, where the animal wouldjump out of the water and swim rapidly away from the sonar,'' said PatrickMiller, the study's lead author and a researcher at the Woods Hole OceanographicInstitution. "We didn't observe any sorts of extreme reactions.''
The new sonar has come undergreater scrutiny after a biologist hired by the National Marine FisheriesService suggested a possible link between Navy traditional sonar tests and earhemorrhages that fatally disoriented the animals.
In March, at least 16 whales offour different species beached themselves in the Bahamas. Seven died, andinitial autopsies suggested the deaths might have been linked to the Navy tests.
The latest research took place offHawaii in 1998. Miller and his colleagues first recorded the whale songs withoutthe sonar and later asked the Navy to transmit the signals.
Of the 16 whales monitored, fivestopped singing altogether. The remainder sang on average 29 percent longer whenthe sonar was activated than without it. The findings appear in Thursday's issueof the journal Nature.
The research, sponsored by theNavy but conducted by independent scientists, said it wasn't clear how much of athreat the sonar and its effects on mating songs pose to whales.
The whales might just becompensating for the noise, Miller said. Still, he added, the Navy should avoidactive breeding areas when using the new sonar.
"Weneed to take a commonsense approach to reducing how much animals are exposed tosound — not only Navy sonar but all the sounds in the ocean like shippingtraffic, whale watching traffic, construction and underwater explosions,''Miller said.
Humpback whales are known fortheir acrobatics and the underwater songs males use to attract mates. Theendangered species received full protection from commercial whaling in 1966.
Animal-rights activists, some ofwhom had tried to stop the latest research by swimming near the test site, saidthe Nature study authors didn't do enough follow-up on the animals after thetests.
"Theydidn't look at results on fish or anything else,'' Benjamin White, of the AnimalWelfare Institute, said Wednesday. "The whole study was based on theassumption that the effects would be immediate and obvious.''
Miller's research and otherprojects sponsored by the Navy will be used in an environmental impact statementof the new sonar expected to be released later this year, said Lt. Bill Speaks,a Navy spokesman.
On the Net: The journal Nature: http://www.nature.com
Woods Hole OceanographicInstitution: http://www.whoi.edu
U.S. Navy: http://www.navy.mil
Animal Welfare Institute: http://www.animalwelfare.com