OMI OMI Logo

Frequently Asked Questions
About Low Frequency Active Sonar (LFAS)




What is Low Frequency Active Sonar (LFAS)?

LFAS is an underwater military system that the U.S. Navy has created to detect "quiet" submarines.


How does it work?

The system involves projecting an extremely loud low frequency sound into the ocean and then listening for the echoes. This sound is produced at incredibly powerful levels, making sound waves travel over great distances in the ocean. We understand that this sonar will operate at 230-240+ dB. This decibel level represents over 100,000 times more acoustic intensity than a very loud ship engine underwater.


What is the impact of humans exposed to loud underwater sounds?

High intensity (pressure) sound waves are KNOWN to be harmful. Experiments with humans by the U.S. Navy have shown that physiological damage occurs from loud sounds in the water. Symptoms include disorientation, memory loss and seizures.

On March 10, 1998 one human in the water in Hawaii was exposed to the LFAS at 120 dB. She was seriously disoriented when she left the water and diagnosed by a physician as having acute trauma. She reports it took months for her to recover.


What is the impact on marine life exposed to this sonar?

Aquatic animals are very vulnerable to high sound levels especially those with air filled lungs and swim bladders. Whales and dolphins are especially vulnerable because they are acoustic animals. Powerful underwater sounds can kill them by causing internal bleeding from ruptured tissues, or deafness. If a mammal's hearing is impaired this causes difficulties in navigation, feeding, communication, and mating. So, therefore, a deaf whale is a dead whale.


Has this sonar ever caused harm to whales and dolphins in the past?

Yes. In 1991 Nature published an article linking three strandings of beaked whales in the Canary Islands to visible U.S. Navy maneuvers in 1985, 1988 and 1989. These were the only times that whales stranded in the Canary Islands.

Another article in Nature (March 1998) argues that a mass stranding of beaked whales in 1996, in the Mediterranean Sea near Greece, was caused by LFAS transmissions by NATO. Navy personnel report the stranding coincided perfectly with the movement of the transmitting ship. According to the NATO report on this incident, these whales were exposed to 150-160 dB.

The U.S. Navy conducted low level tests (between 120-203 dB) of the LFAS off Hawaii in March 1998 with the following results:

Navy scientists report LFAS tests conducted on blue and fin whales in waters off California in 1997 resulted in blue whales decreasing their vocalizations by 50% and fin whales by 30% when the sound was on.

In response to similar LFAS testing off the coast of California, gray whales changed their migration route from over 1km away in response to LFAS transmissions at 180 dB.


What happened to the three separated calves seen in Hawaii during the LFA sonar tests?

One calf was rescued and taken to the Sea Life Park in Honolulu. It is assumed the other two calves died since they could not survive being separated from their mothers. Whale calves need their motherís milk to survive.


Is it true that the LFAS tests conducted in Hawaiian waters in 1998 were next to the Humpback Whale Sanctuary?

Yes, the U.S. Navy's LFAS testing was conducted on singing humpback whales in the most vulnerable of whale habitats: their nursery and mating grounds. These whales had just traveled 2,500 miles one way from Alaska to the warm, protected waters of Hawaii to give birth, nurse their calves and mate.


Who approved the LFAS tests on the humpback whales near the whale sanctuary?

The tests were approved by the National Marine Fisheries Service (NMFS) which is part of the National Oceanic and Atmospheric Administration (NOAA) under the U.S. Department of Commerce.


What is the role of NMFS?

They are responsible for developing, implementing and administering programs for the protection, conservation, and recovery of marine mammals.


What does the Navy say about their LFAS test results off Hawaii?

The scientists, hired by the Navy to do the testing, wrote a report entitled, Quicklook: Low Frequency Sound Scientific Research Program Phase III.

On page 5 of this report they stated: "The research did not use the full source level of LFA." (Here they refer to potential source of 240 dB.)

On page 6 of the same report they said: "...this Phase III research was specifically designed to expose animals to LFA sounds at levels that are not harmful." (Here they refer to 120-203 dB.)

In the report's Executive Summary they also said: "it will be difficult to extrapolate from these results to predict responses at higher exposure levels."


I thought 1998 was the "Year of the Ocean." In support of this the United Nations asked countries to sign a charter to protect our oceans and its inhabitants. Did the United States sign this charter?

No. Of the sixty (60) countries that signed the Ocean Charter, the United States was not one of them.


What is the Navy doing now that their LFAS testing period is completed?

The Navy published a Draft Environmental Impact Statement (DEIS) in late July 1999. The public comment period on the DEIS closed on October 28, 1999. The Navy is required, by law, to incorporate the questions and answers raised by the public in the Final EIS when published at a future date.

On August 12, 1999, just two weeks after the release of the DEIS to the public, the Navy applied to the National Marine Fisheries Service (NMFS) for a Letter of Authorizaion (LOA) concerning LFAS operations. This LOA is a permit to harass marine mammals while operating LFAS worldwide for a period of time, not to exceed 5 years, beginning in FY2000 (October 1999).


Since the public had an opportunity to comment on the Navy's DEIS, did the public have an opportunity to comment on the Navy's requested LOA to harass marine mammals?

Yes, the public had an opportunity to provide written comments about the Navy's LOA request to the NMFS. Letters had to be postmarked no later than November 22, 1999 and sent to: Donna Weiting, Chief, Marine Mammal Conservation Division, Office of Protected Resources, National Marine Fisheries Service.


What is the decibel level the Navy has asked permission to use in their LOA request to NMFS?

The NMFS announcement of the Navy's LOA request states that a 180 dB sound field will extend 2 kilometers from the ship. This means that the source level from the ship will be 246 dB.


What is the difference in impact on marine life when LFAS is used at 203 dB which was the highest level in the Hawaii tests as compared to 246 dB which is the level the Navy intends to use the system at in normal operations?

As you can imagine 246 does not equal 203. Because the decibel scale is logarithmic, higher dB values reflect much higher sound pressure levels. Therefore, a decibel level of 246 represents 20,000 times more acoustic intensity than 203 dB.

No one knows the impact to marine life at 246 dB. If at much lower dB levels we see:

We can't imagine what would happen at 246 dB, except to know that the LFAS will put marine life at risk in all the oceans of the world.

The Nature March 1998 article stated that, "The adverse effects of low frequency sound on whales are poorly studied. But, many scientists warn that at high levels as occurs with the LFA sonar, they (the results) could be dramatic."


What are major environmental groups and respected scientists saying about the Navy's DEIS and their LOA request to harass marine mammals with LFAS?

Several scientists and environmental groups have pointed out numerous discrepancies in the Navy's DEIS and their LOA request. They also believe the DEIS provides insufficient data for LFAS to be used safely. The Navy has chosen to test the LFAS at levels much lower than they intend to deploy it at in the oceans worldwide. Therefore, we do not know the true impact on ocean life and neither does the Navy.

Each one of these environmental groups and scientists has spent a great deal of time and effort to understand and communicate their concerns on this very confusing and complex issue. We recommend that you take the time to read their comments. Please see our "Links To More Info" page.

What does the Marine Mammal Commission say about the effects of LFAS on marine life?

The Marine Mammal Commission, (a federal agency created to help protect marine mammals), expressed grave concerns in their 1997 annual report to Congress about the effects of the sonar on whales and other marine life. Specifically their report states:


When is the Final EIS (FEIS) due out?

The FEIS was published in late January 2001. It is an extremely long document and basically says nothing different from the DEIS.


What has the Navy done since the FEIS was published?

They have applied to NMFS for a permit and a LOA to deploy LFAS. Both of these are required under the Marine Mammal Protection Act and the Endangered Species Act.


What has NMFS done since the FEIS was published?

They have accepted written comments from the public and held three public hearings between April 26 and May 3, 2001.


What is the opinion of our congressional leaders about the LFAS testing and the impact it is having on our marine life?

As of this date, Congress, as a whole, has made no official comment on these tests.

Part of the problem for our elected representatives is that they have not been told the truth. Many of you have written your representatives with your concerns, asking them to find out what is going on. In turn the representatives write to the Navy asking for specifics. The Navy, however, has consistently responded to congressional representatives with inaccurate and misleading statements. Please see our "Misinformation" page for specific examples.

OMI has made it a priority to point out the U.S. Navy's inaccurate statements about LFAS and provide congressional representatives with the truth.


If whales have been on this planet for 50 million years, obviously they have learned to adapt to survive. Why should we not assume that they would adapt to the LFA sonar?

To answer this question I would like to quote Farley Mowat, from his book, A Whale for the Killing,

"Here is as good a place as any to reply to a question I have sometimes been asked. Why is it that, if whales have such large and developed brains, they have not been able to avoid destruction at man's hands? The answer seems obvious. The whales never dabbled in the arcane arts of technology and so had no defense against that most deadly plague. In time they might have evolved a defense, but we gave them no time. The answer raises a counter question: Why is it, if man has such a remarkable intelligence, he has been unable to avoid an almost continuous acceleration of the process of self-destruction? Why, if he is the most advanced of beings, has he become a threat to the survival of all life on earth?"


If I do not want the U.S. Navy to expose marine life or humans to the LFAS what can I do?

Let your voice be heard. Every one of us has a voice, and when we as a group make our concerns heard, we could be more powerful than any organization or government. Go to our "Actions You Can Take" page for specific steps to take.


Glossary:
DEIS - Draft Environmental Impact Statement
FEIS - Final Environmental Impact Statement
LFA or LFAS - Low Frequency Active Sonar
LOA - Letter of Authorization
NATO - North Atlantic Treaty Organization
NMFS - National Marine Fisheries Service
NOAA - National Oceanic and Atmospheric Administration
OMI - Ocean Mammal Institute


Back to OMI Home Page