Sonar study fails to explain strandings

Posted on: Thursday, April 9, 2009

Sonar’s effect on dolphins minimal

By William Cole
Advertiser Military Writer

In a study replicating Navy sonar, the Hawai’i Institute of Marine Biology found that a captive bottlenose dolphin had to remain relatively close to a high-intensity sonar source for a prolonged period to experience even temporary hearing loss – a finding the Navy seized upon to say it “may have vastly overestimated impacts of mid-frequency active sonar on marine mammals.”

“We are still reviewing the report, but the research indicates that higher decibel levels are required to cause a shift in hearing than in the Navy’s more conservative models,” said Mark Matsunaga, a spokesman for U.S. Pacific Fleet.

But the Natural Resources Defense Council, which has sued the Navy repeatedly over alleged harm by Navy sonar on marine mammals, said the Hawai’i Institute findings pertain to one bottlenose dolphin in captivity and don’t speak to sonar effects on other marine mammal species.

The findings by the Coconut Island-based institute, a research arm of the University of Hawai’i, were published online yesterday in the journal Biology Letters.

“At bottom, this paper does not address the central concerns that the scientific and environmental communities have had about mid-frequency sonar,” said Michael Jasny, senior policy analyst with the NRDC. “Those concerns involve types of impacts other than hearing loss – such as behavioral impacts and stress effects, and such impacts have been found to occur at vastly lower thresholds of sonar exposure.”

Jasny said the Hawai’i Institute study adds a “data point” to the ongoing study of sonar impact on marine mammals.

The biggest concern, Jasny added, is over injuries to deep-diving whales from sonar that can cause the animals to stop vocalizing, abandon habitat and, in worst-case scenarios, suffer hemorrhages or emboli similar to the “bends” sometimes experienced by divers.

The Hawai’i Institute report, by T. Aran Mooney, Paul Nachtigall and Stephanie Vlachos, said there is increasing concern that human-produced ocean noise is adversely affecting marine mammals, with several mass strandings possibly caused by Navy mid-frequency sonar.

“However, it has yet to be empirically demonstrated how sonar could induce these strandings or cause physiological effects,” the report states.

Experiments were conducted in open-water pens at Coconut Island from August to October 2007 using a captive-born and trained Atlantic bottlenose dolphin accustomed to noise exposure experiments, according to the study.

The report said the “fatiguing noise” was an actual mid-frequency Navy sonar signal recorded in Puget Sound, Wash., in the summer of 2005 before a marine mammal stranding event.

Nachtigall said non-invasive electrodes were placed on the dolphin to detect brain wave patterns in response to the sound. According to the Hawai’i Institute, to get a temporary hearing loss, a dolphin would have to remain for five minutes within about 120 feet of a sonar source to receive the threshold 214 decibels of sound.

Navy sonar typically operates at 235 decibels at its source.

Nachtigall, the director of the Marine Mammal Research Program, said the study is groundbreaking in that it is the first to examine the direct effect of sonar on dolphins. It also shows Navy sonar is no different than other ocean sounds, and is similar to oil drilling noise or the underwater sounds from a tanker, which can be 220 decibels in a lower frequency, he said.

“So there are a lot of loud sounds in the ocean – not just Navy sonar,” Nachtigall said.

The study was funded by Congress through the Office of Naval Research.

Reach William Cole at wcole@honoluluadvertiser.com.

Source: http://www.honoluluadvertiser.com/article/20090409/NEWS10/904090342/1001

Two dead whales and a mass fish kill on Kaua'i, Ni'ihau – Is the Navy to blame?

From the Hawaii Independent: http://www.thehawaiiindependent.com/hawaii/kauai-hawaii-regions/2009/03/09/fish-fears-on-kaua%E2%80%98i-ni%E2%80%98ihau-%E2%80%93-is-the-navy-to-blame/

Fish fears on Kaua‘i, Ni‘ihau – Is the Navy to blame?

Posted March 9th, 2009 in Kauai, Niihau

by Joan Conrow

It’s been weeks since a massive fish kill was discovered on Niihau, but those living on the privately-owned island remain afraid to eat the reef fish that are a dietary staple.

“For the Niihauans, fishing isn’t a hobby, it’s how they put food on their table,” said Don Heacock, the state aquatic biologist on Kauai. “It’s one of the few places in Hawaii nei where people are still practicing traditional subsistence fishing. And now they’re afraid to eat the fish because they don’t know what happened to them.”

Bruce Robinson, whose family owns the island that lies off Kauai’s western shore, first spotted fish washing ashore on Jan. 17, but did not contact state officials until Feb. 2, when he brought Heacock a sample of about 100 dead fish.

“But very few were fresh and most were seven or more days old,” said Heacock, who selected the freshest fish he could find from the sample and gave it to Thierry M. Work, a federal wildlife disease specialist, for a necropsy.

Work found that the fish had suffered severe trauma to the gills. “The most significant finding was the acute inflammation and swelling of the gills that was suggestive of an acute insult,” according to the necropsy report. “One possibility is some sort of chemical irritant, however, the identity of such a cause cannot be determined based on available information.”

Heacock said he observed hundreds of dead fish on Niihau and many had distended swim bladders, a phenomenon more typically associated with deepwater fish that are brought up to the surface. Fish use their swim bladders to “sense, hear and feel sounds and vibrations underwater,” he said.

“If there was a very large underwater explosion, for example, fish would feel that, and if it was loud enough, it could kill them,” Heacock said. “It could destroy organs and tissue.”

In response to concerns that the fish might have died during an illegal fishing operation using bleach, Work researched the scientific literature and found that “exposure to chlorine causes a distinct lesion, which I did not observe in this particular fish. If I was going with the literature, I would not suspect chlorine,” Work reported.

Heacock said that Robinson also reported a baby humpback had washed ashore on Niihau on Jan. 21. Based on photographs, Heacock said the whale was “very fresh. I could see no noticeable external signs of trauma, but it was laying on one side and I don’t know what was under that.”
A large swell apparently washed the calf away before Heacock and others were able to get to Niihau on Feb. 4, where they collected dead fish and monk seal scat and observed several seals, which appeared healthy.

On Feb. 9, another humpback calf washed ashore on a section of beach between Kekaha and Kauai’s Pacific Missile Range Facility. The whale had several broken ribs, but it’s unknown whether that injury occurred before or after the whale died, Heacock said. Necropsy results are still pending.

“We don’t know if the fish kills and the two baby whales washing ashore are related, but they might be,” Heacock said. “We do not know if there was some kind of sonic experiment or sonar testing going on. We do know there were military activities going on during that period. Several commercial fishermen said they’d seen some large Navy ships, Marine Corps helicopters and even Australian ships around Niihau in that time period.”

Paul Achitoff, an attorney with Earthjustice, said that the Navy’s counsel confirmed that the January 2009 undersea warfare training exercise (USWEX) began at 4 p.m. Jan. 15 and ended at noon Jan. 18.

The Navy did use mid-frequency active sonar during antisubmarine training exercises last year. However, PMRF spokesman Tom Clements refused to confirm whether the Navy had used sonar during this year’s USWEX, or even that military activities had been conducted at all.

“If an anomaly occurred at that time that people are trying to connect to our activities, we’re saying they were no different than the activities that have been done on the range over the past 40 years,” Clement said.

Marine mammal strandings have occurred in Hawaii following sonar exercises, including two pygmy sperm whales that washed up on Maui and Lanai after the April 2007 USWEX and a beaked whale that came ashore on Molokai during one of the exercises last year. In July 2004, a pod of melon-head whales came into Hanalei Bay shortly after the Navy used sonar. The Navy contends there is no connection between such strandings and sonar use, but has never released any necropsy reports on the dead animals.

In a response to an email posing additional questions, Clements wrote: “As far as ‘loud noises underwater,’ as you know, there are many anthropomorphic sources of sound in the water, including recreational and commercial boat traffic that crosses our range. Our activities that can cause sound in the water are managed and quantified, as expressed in the Hawaii Range Complex EIS completed in 2008.

“And regarding the introduction of toxic or noxious chemicals, if your question refers to operations specifically designed to test or train with or against chemical agents, than the answer is ‘no.’ The PMRF range did not have any spills or accidents resulting in unintended releases. Most human activities on and in the water can potentially introduce chemicals into the ocean, from sunscreen to diesel fuel emissions.”

When asked whether any intended chemical spills or releases occurred, and why the Navy declined to comment on the date or nature of its activities, Clements replied in a second email: “I believe I did respond within the context of the question by distinguishing between intended (operations specifically designed) and unintended (spills or accidents). Not commenting specifically on all-inclusive military operations within a given parameter of dates is not unusual.”

Heacock said he recommended that state officials ask the Navy for more information about the activities it was conducting when the fish and whales died. He also suggested testing samples collected from the fish kill for contaminants under the National Water-Quality Assessment program (NAWQA), but state and federal officials balked at the $15,000 price tag.

“I only recommended that because we’re dealing with human health and safety issues,” Heacock said.

“The [state] Department of Health issued warnings not to eat fish if it smelled or tasted strange, but there are many toxins with no odor and no taste. The Niihauans have a right to know what happened to their fish.”

Both Heacock and Work said fish kills and marine mammal strandings should be reported immediately so necropsies can be conducted before the animals begin to decompose.

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