Surveillance Towed Array Sensor System Low Frequency Active
sonar is the U.S. Navy's newest must-have defense technology.
The Navy claims that LFA sonar will be able to detect today's
"quieter" submarines so reliably that it plans to deploy LFA
routinely throughout most of the world's oceans. The only
problem is that LFA sonar may harm whales and other marine
mammals. This sonar will generate one of the loudest sounds
that human beings can make in the ocean. Worse, because they
are low-frequency in nature, these sounds can travel for
hundreds of miles, effectively ensonifying thousands of cubic
miles of ocean.
The Humane Society of the United States fears that LFA sonar
may pose too great a risk of causing severe adverse effects to
marine animal populations. LFA may damage or destroy marine
mammal hearing, as well as disrupt calving, breeding, feeding,
and communication. There may be other impacts, too, like those
seen when a glass shatters as an opera singer hits a high note.
A sound wave can cause material that resonates in its frequency
to vibrate, shatter, shear, or tear. Some air spaces in mammals
(and fish) may react to LFA sonar in this manner. All of this
is too high a price to pay for questionable security against
the latest breed of submarines.
The Navy has produced an Environmental Impact Statement, as
required by law, to assess the effects of LFA sonar technology
on the marine environment. Based on the EIS, the National
Marine Fisheries Service is producing regulations that would
govern how LFA sonar could be used in the world's oceans. The
HSUS (along with several other organizations) believes the Navy
and NMFS are proceeding without giving adequate consideration
to the potential harm LFA sonar could inflict on the marine
environment. We have produced comments at every step of the
regulatory process, and we have communicated via various
channels with the Navy, NMFS, and Congressional officials
expressing our concerns about LFA sonar. Our principal concern
is that the environmental analyses upon which the Navy and NMFS
are relying have several shortcomings:
- Their assessments are based on insufficient data about
how sound affects marine mammals, sea turtles, and other
marine animals.
- They overinterpret the small amount of data available on
sound and marine mammals, and reach non-precautionary (and
poorly supported) conclusions that LFA sonar will not harm
marine mammals in any significant way.
- They fail to adequately consider the possibility that LFA
sonar could seriously injure and even kill marine mammals,
sea turtles, and other marine animals. At the same time, they
place unjustified confidence in the Navy's ability to prevent
such injuries and deaths through detection of marine animals
within a "zone of exclusion" around the sound source.
- They do not discuss alternate hypotheses for observed
marine mammal reactions to loud, low-frequency sound.
- They set an arbitrary standard for the level of sound
that will harass or injure marine mammals and sea turtles.
This standard has no empirical basis and is vastly less
precautionary than standards being established by other
countries.
- They neglect to adequately discuss the shortcomings of
LFA sonar in accomplishing the Navy's goal of detecting
"quiet" enemy submarines while remaining undetected
itself.
In March 2000, a mass stranding of beaked whales, minke
whales, and one dolphin occurred off the Bahamas after a Navy
exercise in which mid-frequency active sonars were used. While
beaked whale mass strandings have occurred in the past (many
coincident with nearby naval maneuvers), this was the first
time that a qualified scientist was on hand to collect the
appropriate samples from fresh carcasses to determine cause of
death. The most recent results of the on-going investigation
into this incident indicate that these whales died from the
impacts of a loud sound acting on their air spaces—that is,
from resonance effects. The Navy has had to admit that
mid-frequency sonars may pose a serious risk to certain marine
mammal species; even so, it continues to maintain that LFA
sonar, which operates at a lower frequency than the Bahamas
sonars, will be safe for all marine mammals. The HSUS strongly
objects to this cavalier interpretation.
While The HSUS recognizes the need to develop a system
capable of protecting our servicemen and women against a new
generation of submarines, LFA and other active sonars pose a
terrible risk to endangered and threatened marine species. The
Navy should abandon plans to deploy LFA sonar worldwide and
focus instead on other promising technologies that do not pose
such a risk. It must also reevaluate its use of all active
sonars and consider mitigation measures that will protect
marine mammals from the negative impacts witnessed in the
Bahamas.
More Information in PDF Format
Testimony
on LFA Sonar
Commentary
on Draft Environmental Impact Statement on SURTASS LFA
Sonar
Commentary
on the Proposed Rule Regarding Taking of Marine Mammals
During SURTASS LFA Sonar Operations
Presentation
at Acoustical Society of America Conference
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