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May 2001 Ms. Donna Wieting
Chief, Marine Mammal Conservation Division
Office of Protected Resources
National Marine Fisheries Service
Silver Spring, MD 20910-3226 USA
Dear Ms. Wieting:
Let me introduce myself. My name is Joseph E. Blue. I have my BS Degree
in physics with majors also in biology, chemistry and mathematics, my MS
in engineering science with my thesis being on Acoustic Cavitation and
Bubble Instabilities and my Ph.D. in mechanical engineering with an
engineering acoustics option.
I am a former member of the Navy Civil Service Senior Executive Service
(SES). In that position I was in charge of the Underwater Sound Reference Detachment (USRD) of the
Naval Research Laboratory which became the Underwater Sound Reference
Division of the Naval Undersea Warfare Center Division Newport. The USRD
was the lead laboratory for SPAWAR in contracting for the first 18 LFA
projectors. During that procurement process, an LFA projector was tested at high levels (~207 dB
re 1 mPa at 1 m) in USRD's Lake Gem Mary Facility in Orlando. This test was conducted while I was on travel as I would have not
allowed it had I been informed in advance that it was going to be done. When I returned, I received several telephone calls from
neighbors complaining about rattling dishes, items dancing on shelves
and fear of structural damage to their home foundations.
I banned any further high power tests in the USRD facilities.
I am generally in favor of sonar systems as I have seen where better sonar
could have prevented many combat deaths.
However, from my 40 years of experience in underwater acoustics,
I have learned that sonar can be dangerous to humans and sea animals in
ways that most people associated with the development of these systems
cannot imagine. I also learned that the focus is on systems that work with little thought to
negative environmental consequences by engineers and scientists who are
not familiar with the biological aspects of sound in the sea. The reward system is for positive results, not for pointing
out the negative. Such, I fear based on my experience, has been the case for LFA.
LFA might be an important system if alternatives to it cannot be
found. However, in my scientific opinion, LFA should not be allowed to proceed under the
currently proposed FEIS LFA has the potential of doing great harm, not only to marine
mammals, but also to the many people who derive their livelihood and
food from the sea. A potentially fatal flaw in the analysis of LFA effects by biologists hired
by SPAWAR as bioacousticians is their lack of understanding of acoustics
as a branch of physics. That leads them to the use of anecdotal observations that, in
the case of LFA, is not supported by a large enough database to arrive
at statistically significant conclusions necessary for the SPAWAR nor
the opposing sides of this issue to feel confident enough to proceed.
A case in point is the insistence by the SPAWAR LFA office that
enough testing has been done to ascertain the safety of the system to marine life.
Even that small amount would not have been done if it were not
for the insistence by environmentalists that sonar was killing marine
mammals. Until the stranding of many marine mammals during Navy exercises in the Caribbean,
the Navy attempted to blame every stranding as due to causes other than
sonar. Not until the Navy was presented with proof that the stranding
was due to sonar did it get serious about sonar stranding evidence.
Even now, the Navy tries to isolate the damaging effects to
frequency regimes. Examination of Minnaert's equation for relating bubble size to resonance frequencies
shows that there are air cavity volumes of all sizes that may resonate
in marine mammals and other sea life.
When acoustic displacements get large enough in a sea life form,
tissue tearing will occur. One
cannot define an absolute displacement size for this to occur because
the significance of the displacement depends on the size of the organism
and the level of the excitation source.
Thus, it is not sufficient to say that LFA is safe because it is
a different frequency regime than the sonars that caused the Caribbean
stranding phenomena. That
represents a gross misunderstanding of the resonance process.
Further, not all marine life damage can be attributed to air
cavity resonance alone. Damage
to hearing apparatus of marine mammals such as uncovered by Dr. Darlene
Ketten from Woods Hole illustrates my point.
The entry to the brain and on to the hearing apparatus was
through a nerve foramen from a sinus cavity. The air cavity of the sinus
will not vibrate as a bubble because the bony sinus cavity presents a
different acoustical impedance to the sonar.
The whole of the lung/bronchial tubes/trachea/sinus/air-volume
complex must be considered. Modeling
of this complex air volume may be possible by considering the lung to
vibrate like a bubble and the remaining part act as a Helmholtz
resonator. A coupled
resonant system such as this can explain the punch through at the nerve
foramen site, which is soft compared to the bony sinus cavity, thus
concentrating the displacement on the soft foramen site into the brain
where Ketten observed the bloody mass and hearing apparatus trauma.
SPAWAR's contention that no damage has been done during LFA tests
because of lack of evidence of marine mammal deaths is not convincing.
The endangered right whale apparently escaped harm as they float
when killed as opposed to most other whales that sink when killed.
Many unrecorded deaths would go unnoticed if they sank rather
than strand themselves.
The LFA system idea was hatched during the Cold War.
The threat from quiet diesel submarines from rogue nations may be
better addressed by the military intelligence community and lower power
shorter range systems. The
end of the Cold War should have caused a more thorough examination of
LFA rather than following the lead of the military/industrial complex
that Eisenhower warned us about. Apparently,
the threat was redefined from the original cold war to rogue nation
threats to allow the LFA program to continue.
My belief is that there are more pressing security problems that
are not being pursued where the money being spent on LFA should be
channeled.
Sincerely,
Joseph E. Blue, Ph.D.
Orlando, FL 32806
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