ENVIRONMENT
Navy’s sonar tests seem to
By Lori Tighe
have little effect on whales
Star-BulletinEarly results of the Navy's winter sonar experiments show the sounds caused 10 of 17 male humpback whales to stop singing, and some to swim away.
But most of the whales that stopped singing resumed within an hour after the Navy ended the sonar.
The experiments, held from February to March off the Big Island's Kona Coast, drew protests from environmentalists fearful of the sonar's effects on the mating of endangered whales.
A handful of legal battles ensued, all of which ended in favor of the Navy to continue testing whales with its low-frequency active (LFA) sonar, used to detect submarines.
"This first step we took was an initial investigation. The answer we found is, It doesn't seem to bother them. I was surprised," said Christopher Clark, lead scientist on the experiment.
"I thought that at 140 db (decibels) they would consistently and immediately respond. But they didn't."
Clark, a bioacoustics scientist at Cornell University, and a team of researchers on a ship played sounds from 120 to 150 decibels underwater at a singing male for 42 seconds, every six minutes for an hour.
"If you look at the data, there was almost no effect," said Paul Nachtigall, Ph.D., director of the Marine Mammal Research Program at the Hawaii Institute of Marine Biology. "They really didn't bother the whales."
Another local supporter of Clark's work, Joe Mobley, Ph.D., with the University of Hawaii-West Oahu, also agreed the whales' response to the sonar "suggested no big deal."
"Whales stop singing all the time. Is it something to worry about? No," Mobley said. Noteworthy reactions would have included a broad abandonment of the area by the whales or a lot of surface activity, like slapping of tails and breaching, which scientists didn't see.
But Emily Gardner, state marine protected species program coordinator, considered the findings noteworthy.
"Singing is linked to courtship and mating. Disruption of courtship and mating could potentially impact the reproductive success of individuals and ultimately lead to a reduction in population," she said.
"You know mating -- it's all on timing. If the LFA goes off, he stops singing; he might miss his chance."
But Clark and the Navy ignored other data related to the experiments, such as three whale or dolphin calves abandoned by their mothers in the testing area, said Marcia Green, Ph.D., founder of Ocean Mammal Institute.
Green's team observed a lone humpback calf, a lone dolphin calf and a lone melon-headed calf, rescued and now living at Sea Life Park, all in the low-frequency active area off the Kona Coast, Green said.
"In all the years I've researched these animals since 1985, I've never seen a calf abandoned by its mother," Green said. "The Navy ignored that."
As for internal damage or long-term effects on the whales, Clark and the Navy have no idea, said Paul Achitoff, attorney for Earthjustice Legal Defense Fund, who led the legal charge against the Navy.
The Navy's low-frequency active system will operate at a higher level than sounds used in the experiment, Achitoff said.
