Navy changes claim on sonar use
By Jan TenBruggencate
Advertiser Science Writer
LIHU'E, Kaua'i — The Navy now concedes that warships used active sonar off Kaua'i July 3, just before a pod of some 200 deepwater melon-headed whales appeared in Hanalei Bay shallows.
The Garden Island via Associated Press
Marine mammal experts on the scene said the whales were behaving strangely and ultimately left a dead infant behind as they were coaxed out of the bay by beachgoers on canoes and kayaks.
A pod of about 200 melon-headed whales swam near shore in Hanalei Bay on July 3. Initially, the Navy said that sonars were used after the whales behaved strangely that morning.
Navy officials insist that the sonar was used too far away from Kaua'i — one ship about 30 miles and one 37 miles northwest of Hanalei Bay — to have affected the whales. But investigators say they're not ready to accept that conclusion as debate continues over the effect of sonar on marine mammals.
"I think that it's premature to make that determination until we have all the facts together," said Donna Wieting, deputy director of the National Oceanic and Atmospheric Administration's Office of Protected Resources.
Authorities in several countries are probing links between high-volume sonar and whale injuries, a field that Wieting said was not even generally considered an issue as recently as five years ago.
"I think it's clear that we now know that certain intense incidences of man-made noise can injure or kill marine mammals," said Erin Heskett, senior program officer with the International Fund for Animal Welfare and a member of the U.S. Marine Mammal Advisory Committee on Acoustic Impacts on Marine Mammals.
He said he and others on the committee have been briefed by the Navy about the Kaua'i incident and have watched the Navy's position change over time. He said he is frustrated by the lack of consistency.
"They are now acknowledging that indeed the two ships turned on their sonar. From my perspective, we need to get the story straight. We need to get our facts right and try to come up with a solution," he said.
The Navy initially said that sonar could not have been responsible for the whale behavior because sonar was first employed at 8:33 a.m. on July 3, an hour after the deep-ocean whales were first spotted in a tight pod in the shallows of Hanalei Bay. The most consistent time for the first sighting of the whales in Hanalei is 7:30 a.m., although Navy officials say they are investigating a possible earlier sighting.
U.S. and Japanese navy ships were using the sub-finding sonar technology as part of a RIMPAC multi-national naval exercises off Kaua'i's Pacific Missile Range Facility. Six sonar-equipped ships were involved and all used their sonar during the exercise. Active sonar uses an intense burst of sound that travels through the water, and identifies the location of enemy submarines when the sound echoes off their hulls.
Two Japanese ships tested their sonar before the exercise began. Pearl Harbor-based Navy Pacific Fleet spokesman Jon Yoshishige yesterday said a review of the data from the exercise shows that one ship tested its active sonar at 6:45 a.m., and that a second ship tested its sonar at 7 a.m.
Navy spokesman Lt. David Benham yesterday said that, following standard procedures, every ship conducted a full 360-degree visual search of surrounding waters to make sure no whales or civilian boaters were in the region before turning on the sonar.
NOAA's Wieting said Navy officials have also reported they were using the sonar a day earlier.
"They actually were testing the sonar and using it starting at midday on the second (of July)," as they were in transit from Pearl Harbor to Kaua'i, she said. Yoshishige confirmed that Navy ships did test their active sonar in the Kaua'i Channel on July 2.
Wildlife officials worldwide have been studying the link between the use of active sonar gear and marine mammals, particularly after 17 whales were found dead in the Bahamas following a military sonar exercise. In that case, the Navy conceded that under certain conditions, loud mid-frequency sonar could damage marine mammals.
In the Kaua'i case, there is no evidence that sonar was directly or indirectly associated with the whales' activity. Marine mammal veterinarian Bob Braun said that while he could see no injured whales, the pod as a whole was behaving as if under stress on July 3.
The Navy halted its sonar use at 4:45 p.m. July 3, immediately after learning of the whales' behavior, Benham said. Sonar use continued to be prohibited off the Pacific Missile Range until July 7, he said.
Kayakers and canoe paddlers used a cable of twisted leafy vines to herd the melon-headed whale pod back out the sea on July 4. The next morning, a dead infant melon-headed whale was found washed up on Hanalei Bay's sand beach. Veterinarian Braun said the necropsy on the whale, performed on the Mainland, showed no obvious injuries. The newborn whale appeared to have died because it had not been feeding.
"Either the kid couldn't keep up, or the mom couldn't provide — something like that," Braun said.
Various working theories about the whales in Hanalei have been broached, including Navy sonar, some other ocean noise, whales following an injured pod-mate to shore, or some kind of toxic "red tide" bloom offshore.
Wieting said it is fully possible that no firm cause will be determined.
"It's unlikely that we will be able to know what caused these animals to almost strand. Maybe it was a disease. Maybe it was a noise. Maybe it was something else," she said.
Part of the problem, Wieting said, is that "we know very little about melon-headed whales. We don't know how fast they can swim. We don't know the frequency range of their vocalizations. We don't know the impact of this (sonar) frequency range on them."
Heskett's International Fund for Animal Welfare is one of several large environmental organizations calling on the Navy to employ measures to reduce sonar effects on marine mammals. Suggested techniques involve having trained marine mammal experts on all Navy ships using sonar in testing, gradually ramping up the sound level to give whales time to escape before the noise reaches damaging levels, and reducing the ultimate volume of the sonar.
"Hopefully what comes out of this is the identification of ways to mitigate or improve this situation," he said.
Reach Jan TenBruggencate at jant@honoluluadvertiser.com or (808)245-3074.
