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Low Frequency Active Sonar
Archives: March 2000-May 2001

Low Frequency Active Sonar Systems Overview

Designed as a sonar system for use in undersea surveillence, this proposed network of transmitters could one day keep watch on the world's oceans. Will it affect ocean wildlife?

During trials of the system, significant detrimental effects were observed: abandoned calfs in the Hawaii test area, humpback whales leaving the test area, 80% of humpback whales stopped singing during the sonar tests, a significant decrease in vocalizations of blue and fin whales, and a change in the migration route of gray whales. Navy Environmental Impact Statements have reported minimal effect on wildlife.

The output levels of these tests, while loud, is not radically louder than that of humpbacks and other whales; in fact, whale sounds at their loudest can be twice the intensity of the systems. This system also has a gradual rise time, rather than a sudden clap of sound, which may help minimize the stress on whales and other ocean life.

Whales are not the only concern. Other fish have shown avoidance behavior triggered by sounds much less intense than LFA. This suggests that fish and cetaceans will be affected at some distance from the test sites (ie the area within which the sound will be above observed behavioral thresholds is quite large).

In addition, serious questions have arisen about physical damage to whales caused by acoustic resonance, whereby sound at certain frequencies can resonate within body cavities (the size of the body cavity determines the frequency that will be critical), becoming amplified in ways that cause serious physical damage. See this link for a full report on this effect.


Summer 2001: National Marine Fisheries Service gives preliminary go-ahead for deployment of LFAS.

Feburary 2001: Navy releases its final Environmental Impact Statement. Few substantive changes are made in response to comments to their draft EIS; the Navy still claims little adverse effect on wildlife. Opponents of LFA are evaluating their options, which include lobbying for Congressional oversight hearings, and possible lawsuits to prevent deployment later this year. For the Navy, the next step is to obtain permits from the National Marine Fisheries Service; the NMFS has been part of the EIS team, so opponents do not expect this to be a significant hurdle towards implementation (in May 2000, though, the NMFS did object to a proposed LFA test off the coast of New Jersey, on the basis that the navy's assesment of environmental effects was inadequate--see news note below). Stay in touch with activist groups listed below for the latest news.

December 2000: Jean-Michel Cousteau and Robert F. Kennedy, Jr. write an op-ed piece for the LA Times that was widely distibuted, raising awareness of this issue. See this link for a copy.

September 4, 2000: The Toronto Globe and Mail reports that the Canadian Navy is doing new studies to assure that cetaceans are not present during LFAS testing. "That LFA Sonar can injure whales is still open to debate, but we have adopted the policy of assuming it does, which means ensuring there are none around when we do our tests," said Warren Nethercote of the Defense Research Establishment.

August 14-15, 2000: The Ocean Mammal Institute hosts a symposium in Bar Harbor, ME. Despite invitations to participate, niether the Navy nor the National Marine Fisheries Service sent any representatives. OMI website. Here is a summary of the presentations.

Late May 2000: Navy cancels LFAS tests off New Jersey in response to environmental concerns. See this link for full story.

March 2000: Beaching of 8 whales after tests of a lower intensity sonar system north of the Bahamas (see this link); local observers report a marked absence of beaked whales since then, and fear a massive drowning event was triggered, perhaps by acoustic resonance in the whale's bodies (see this link for detailed report by a marine biologist on the scene). Also, a suit was filed in federal court by eleven national and Hawaiian organizations and individuals, aimed at halting the deployment of the LFAS system there (see ENS story).

Contacts for this issue:

The Ocean Mammal Institute has been a leading voice on this issue. Visit their web site for background info and the latest news. The Ocean Mammal Institute, P.O. Box 14422, Reading, PA 19612. (610)670-7386, (800)226-8216,

Another site with a sober yet skeptical overview is the University of California at Irvine LFAS issue guide.

The National Resources Defense Council has been involved in the issue of undersea noise since the mid-'90's. Here is their overview of the LFAS issue. It includes an easy form to send a letter to the Secretary of the Navy.

Here's an editorial from the Christian Science Monitor, written by whale reseacher Linda Weilgart.

Earth Island Institute is also on the forefront of this issue. See this article from their Spring 2000 issue.

The Cetacean Studies Institute has a good overview of the issue and links to related organizations: follow this link.

Navy Drops Criticized Sonar Test off New Jersey

By Marc Kaufman
Washington Post Staff Writer
Saturday , May 27, 2000; A02

The Navy has abandoned plans to test controversial sonar systems off the New Jersey coast following protests by federal regulators and environmental groups that the intense sounds can harm whales and other ocean life.

In a brief statement yesterday, the Navy said its Littoral Warfare Advanced Development test 45 miles off the New Jersey coast this week will proceed
but will "not include active acoustic sources."

The decision, which environmentalists hailed as a first, marks an escalation in a growing dispute over whether efforts by the Navy to test and deploy new types of sonar submarine detection systems are dangerous to sea life. It also comes two months after a dozen whales stranded themselves on two beaches in the Bahamas one day after Navy exercises nearby used the loud, intense noises.

Many scientists believe that whales and other marine mammals can be harmed by the extremely high-decibel sounds--some significantly greater than the sound of a 747 jet at takeoff--created as part of the Navy's new "active" sonar systems. The animals, which rely on sound the way humans rely on sight, can suffer directly with burst eardrums and permanent hearing loss, and indirectly with harmful changes in behavior.

Earlier this month, the Commerce Department's National Marine Fisheries Service (NMFS) sent a letter critical of the proposed test off New Jersey to the Office of Naval Research, saying that the Navy's assessment of potential environmental damage was inadequate. The letter from regional administrator Patricia Kurkul also criticized the Navy for not giving the agency adequate time to review the proposal.

In addition, a letter to the Navy from the director of the U.S. Marine Mammal Commission, a 12-member group of scientists appointed by the president, warned of increased public opposition if the Navy didn't do a better job of investigating the Bahamas incident and others like it.

"If the investigation does not identify the cause of the strandings and steps that can be taken to avoid similar occurrences in the future if the Navy activities are implicated, it is highly likely that efforts to stop the development and use of high-energy sound sources will intensify and possibly block activities important to national defense," wrote director John R. Twiss Jr.

The Navy said soon after the Bahamas incident that it followed standard procedures to protect wildlife and had concluded there was no connection between its exercises and the strandings. A Navy official said yesterday that an "independent review of acoustic, oceanographic and environmental data" is being conducted "to determine whether Navy activities may have had a role in the Bahamas mammal strandings."

The official also said the active sonar tests off New Jersey were dropped because the exercise could not be delayed to allow time to "clarify inconsistencies and points not well understood" regarding the objections by the NMFS.

According to Joel Reynolds of the Natural Resources Defense Council, an environmental group long critical of the Navy's active sonar systems, the decision to cancel active sonar tests off New Jersey marks a significant change.

"We think this is very important because the Navy has now been told it cannot simply reserve a vessel, schedule an exercise and proceed without worry of environmental impacts when dealing with low-frequency sonar systems," Reynolds said. "This is the first time where [the NMFS] told the Navy that it cannot move forward because of a failure to comply with the Endangered Species Act."

According to Reynolds and federal regulators, the site off New Jersey is particularly rich in sea life and would be home to billions of spawning squid in the late spring. The endangered sperm whale feeds on young squid and would likely be in those waters as a result.

The Navy's environmental assessment statement for the tests off New Jersey said that both low- and mid-frequency sonars would be researched, some reaching higher than 210 decibels, as well as sonic effects of small explosions bouncing off the sea floor. In addition, officials said the Navy would deploy the same "sonobuoys"--devices that generate sound waves in the water--as the Navy used in the Bahamas.

Low- and mid-frequency sonar emits sounds that the Navy believes can identify ships better than conventional sonar, especially in shallow coastal waters.

According to NMFS officials, the larger issue of the Navy's use of active, low-frequency sonar worldwide will be revisited this summer when the agency and the Navy release environmental impact statements on a broader use of the technology known as the Surveillance Towed Array Sensor System (SURTASS). Environmental groups have sued to block that system, saying the Navy should have produced an environmental impact statement much earlier.

Copyright 2000 The Washington Post Company

OMI Symposium Quicklook: The Navy’s High Intensity Sonars
By Marsha Green, Ph.D.
Ocean Mammal Institute

This Symposium addressed the increasing concern about the negative impact of active sonar and other military acoustic systems on marine mammals and other life in the oceans. I was personally inspired by the concern for marine life evident in the people attending the Symposium and pleased by the international representation. Attendees included people from environmental, scientific and regulatory communities, as well as ocean-related industry. I know many others who are equally concerned about the adverse impacts of high intensity undersea noise could not attend, and you were missed. Consequently, I am writing this 'Quicklook" in an attempt to include everyone in the ongoing dialogue.

The Navy and NMFS chose not to send official representatives so we were unable to obtain feedback or information from them. Tapes of the proceedings are being transcribed and will be published on our website, Here I will provide a quick overview and key points from the Symposium.

Steve Katona, Ph.D. President of the College of the Atlantic welcomed us to the college and pointed out that, in the past, humans have been more concerned about noise levels on land than in the ocean. However, concern about noise pollution in the oceans has increased recently because human produced underwater sounds have become louder and the Navy's new sonars have been controversial. Steve also pointed out that it was fortunate that Ken Balcomb, the marine mammal scientist who was present during the strandings in the Bahamas last March, reacted so quickly that the bodies were preserved well enough to allow necropsies. Thanks to Ken for acting so quickly.

Our first speaker was Rob Rand, a consultant experienced in acoustics and systems design. He began by noting that it is inappropriate to attempt to bridge the difference between sound traveling in air versus water. He pointed out that the Navy's discussions about the impact of LFA sonar have focused on the conventional concepts of direct effects on the hearing of marine mammals. They have not addressed the effects of the direct transmission of acoustic energy into bodily tissue and resonant cavities which occur when bodies are in the water. In air, 99.97% of acoustic energy is reflected from the body. In water, however, there's no reflection or reduction of energy because the body is mostly water. Therefore, 100% of acoustic energy goes into the body in water. This effect, which can cause tissue rupture and hemorrhaging, has not been adequately addressed.

The Navy's plan is to deploy LFA sonar at an effective source level of as much as 240 dB (the actual source level is classified), which means it could be 180 dB up to 1 km away from the transmitting vessel and, very likely, be 150 -160 dB up to 100 miles away from the vessel. Rob pointed out that the Navy's statement that biophysical damage starts at 180 dB is not appropriate. This is supported by the fact that the beaked whales that stranded in the Mediterranean when NATO tested low frequency sonar (between 250-3000 Hz) in 1996 were, most likely, exposed to 150-160 dB. If whales strand at 150-160 dB we cannot assume that LFA sonar is safe at 180 dB.

In my talk I reviewed the long chronology of events surrounding LFA sonar and the Navy's other high intensity sonar tests. This detailed chronology is on the OMI website at under the heading LFAS. I reminded everyone that the effective maximum source level of LFA sonar at 240 dB was never tested on marine mammals during the Scientific Research Program (SRP) and that the scientists contracted by the Navy to test LFA sonar stated in the "Hawaii Quicklook" that, "it will be difficult to extrapolate from the results [of the Hawaii tests at 145-203 dB] to predict responses at higher exposure levels." Unfortunately in their Draft Environmental Impact Statement (DEIS) the Navy concludes that LFA sonar is safe to deploy at the untested effective source level of 240 dB. They never mention that LFA sonar was tested on marine mammals during the SRP at levels of at least 5,000 times less acoustic intensity and 70 times less power than the maximum deployment level.

Recently we learned that not only LFA sonar, but also the Navy's standard operating sonar, may be related to marine mammal strandings. According to the Navy, the multi-species stranding that took place in the Bahamas in March, 2000 occurred while they were using their standard, mid-range sonar at 3500 Hz and 7500 Hz and 235 dB. Naomi Rose, Ph.D., marine mammal scientist for the Humane Society of the United States, discussed a recent report on this multi-species stranding in the Bahamas (March, 2000). This report stated that necropsies found hemorrhages in the inner ears and some cranial spaces of the beaked whale heads examined from the stranding. There was also hemorrhaging in the acoustic fats. These pathologies are indicative of trauma from an intense acoustic event. Dr. Rose also pointed out the important fact that only seven multi-species strandings involving beaked whales have ever been recorded and that all seven have been correlated with naval activities in the area.

Our next speaker was Linda Weilgart, Ph.D. As a marine mammal scientist with 17 years experience in whale bioacoustics, she gave an excellent, detailed overview of the problems related to LFA sonar. She pointed out that many studies show that fish and whales start avoiding sounds at 115-120 dB re1uPa. These results are consistent in the literature and should be heeded. LFA sonar at an effective source level of about 240 dB would only drop to 120 dB about 250 miles from the source. That means that an area of ocean greater than the size of Texas could be affected by noise louder than 120 dB from just 1 ship transmitting LFA sonar.

She pointed out that the most serious effects of noise are those that affect growth and reproduction. Studies show that fish and shrimp show lower growth and reproductive rates when there's a mere 20-30 dB increase in noise over the normal background level in the ocean. She also noted that the beaked whale strandings in Greece in 1996 and the recent stranding in the Bahamas were discovered only because they did not occur in remote locations and a biologist happened to be present to document the event. How many deaths at sea from noise pollution do we miss?

She pointed out that the Navy's LFA Scientific Research Program (SRP), conducted by scientists contracted by the Navy to see if the sonar was "safe", was only short-term and limited. Only four out of hundreds of marine species which could be affected were studied and only for 1 month each. The SRP did not even study these four species using the sonar at its full deployment power and intensity. Sperm and beaked whales, which are the most likely to be affected, were not studied at all. Effects on prey species, such as fish, were not studied at all. Even at the low test levels the scientists did observe a substantial decrease in blue and fin whale vocalizations in response to the sonar, a dramatic avoidance of the sonar by in-shore migrating gray whales, and a cessation of singing in half the studied humpback whales even at a great distance from the sound source. Decreasing vocalizations or stopping singing could mean finding fewer mates and, therefore, have a negative impact on reproductive rates.

Certainly long term reproductive changes (over years and decades) in populations are the effects of greatest concern, but these are undetectable for almost all cetacean populations. Therefore, determining whether LFA sonar is "safe" or not is an impossible task. Dr. Weilgart suggested that the use of LFA sonar should be avoided especially in coastal areas because that's where most of the animals are.

She also suggested that to avoid conflict of interest situations, such as occurred with the LFA sonar SRP, marine mammal scientists should not have close ties to the paymasters, the acoustic polluters. The Office of Naval Research (ONR) is the leading organization, worldwide, funding research into the effects of sound on marine mammals (over 3 million dollars annually). ONR also funds a substantial part of the total money granted for marine mammal studies in general. She pointed out it is problematic when a significant portion of marine mammal research funding is provided by an organization representing a major acoustic polluter, whose principle mandate is not pure science or the preservation of the marine environment. The prudent course of action would be to use the Precautionary Principle, which states that when an activity raises threats of harm, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.

Lee Tepley, Ph.D. a specialist in electromagnetic wave propagation, reported that while whales in the Mediterranean stranding in 1996 (Reported in Nature, 1998) were exposed to 150-160 dB of NATO low frequency sonar, in the Bahamas they were most likely exposed to less than 160 dB of the Navy's standard sonar.

Our next speaker, Nick Begich, M.D. broadened our perspective by discussing air-born technologies that can be harmful to biological and environmental systems. He discussed the military's HAARP Project (High Frequency Active Auroral Research Project) which projects radio frequencies into the ionosphere. HAARP causes the ionosphere to pulsate. Using it you can concentrate energy, send it into space and reflect it back to earth to see over the earth's curvature. It also can be used to push up the ionosphere, change weather patterns, or knock out computers. The deployment of HAARP violates the Antiballistic Missile Treaty. He also discussed non-lethal weapons that use pulsed microwave energy which can create disorientation, cause nausea, interfere with lung functioning and cause seizures and other behavioral changes. The European Parliament passed a resolution in January, 1999 opposing the use of such weapons. He highly recommended that everyone read, "The Mind Has No Firewall" which is on the US Army War College website ( Begich stated we have to eliminate the secrecy surrounding the use and development of such weapons. Forty percent of this equipment was black funded; that is, Congress didn't know what the funds were being used for.

Our final speakers were Lanny Sinkin and Joel Reynolds, two attorneys who have been involved in the campaign to get the Navy to comply with federal environmental laws during the development and testing of LFA sonar. Lanny Sinkin informed us that, unfortunately, the National Environmental Policy Act (NEPA) has been interpreted by the courts in ways that take the "teeth" out of using it to stop projects that could be environmentally damaging. Under the current interpretation of NEPA, if a federal agency concludes that what they want to do is worth the risk of any potential environmental damage, the court cannot stop the project.

Therefore, both attorneys concluded that we can't rely on litigation alone to stop LFA sonar. Joel Reynolds, senior attorney for the Natural Resources Defense Council and Director of their Marine Mammal Protection Program, stated that we need a comprehensive political strategy including the following:

Lobbying Congress, especially for oversight hearings on LFA sonar with the intent of impacting appropriations.

Publishing editorials and full-page ads opposing LFA sonar.

Getting more scientists involved.

Developing a broad-based public campaign bringing in animal rights groups, environmental groups and peace groups, fisherman and others who make their living from the sea.

Working with the international community, especially Europe, to contact the US Congress with their concerns.

Developing a stranding chart correlating strandings with the timing of naval activities.

Finding a high profile spokesperson for the campaign.

The general message contained in many of the Symposium presentations was that there is increasing evidence that the Navy’s acoustic testing program has not adequately assessed the potential risks of their acoustic systems and they have underestimated their impact on marine life. This concern is supported by the facts that the NMFS recommended formal rather than informal consultation for LWAD 00-2 testing off New Jersey and the NJ Dept. of Environmental Protection initially did not approve the Navy’s Delaware Bay Acoustic Experiment. I am hopeful that this Symposium served to highlight these public concerns so that they can be adequately addressed in the future. The Navy's final Environmental Impact Statement (EIS) on LFA sonar is due to come out in late fall or winter.

Group Discussions

At the group discussions during the Symposium, we discussed the news that President Clinton signed the Ocean Act of 2000 in August. Part of the mandate of this Act establishes a Commission on Ocean Policy with 16 members appointed by the President, (12 members will come from nominations made to the President by individual Congressional representatives) including representatives from government, academia, ocean-related industry, scientists and conservationists. The commission will develop recommendations to strengthen federal ocean policy and promote responsible stewardship of the marine environment.
During the discussions we concluded that it is important that individuals do the following things right now while we are waiting for the EIS to be available:
1. Call your favorite radio show and ask them to talk about the issue. Have them call one of the Symposium Speakers to be on a show.
2. Since we cannot stop LFA sonar through the courts, we must lobby Congress. The best way to do this is for you to write letters to your representatives and get many other people to do the same. See the OMI website for ideas to write about. Call and write (not email) all your Congressional representatives. Keep calling back and talk to their aides. Personal contact is the key.
3. Write a letter to the editor of your local newspaper about LFA sonar.
4. Educate your friends about the issue.
5. Inform environmental organizations and animal rights groups you're familiar with.
6. Buy a video about LFA sonar and send it to your local cable TV station. Ask them to do a program about LFA sonar. Video's can be purchased at ( - Citizens Opposing Active Sonar Technology).

7. Put ads in newspapers.

At the symposium's concluding discussion, participants made the following suggestions:

Naomi Rose, HSUS, write a letter to Congress about LFA sonar to be signed by as many environmental groups as possible.

Joel Reynolds, NRDC, write a letter to the Navy to be signed by environmental groups.

OMI create a subscription computer list where anyone can post important LFA sonar news.

Someone produce a clear and concise "brochure" on LFA sonar that all involved groups can give to people who want information.

All the above be part of developing the broad-based public campaign that will be necessary to stop LFA sonar.

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