Subject: Case Study:US Navy Low Frequency Active Sonar (fwd)

Michael Williamson (pita@whale.simmons.edu)
Mon, 5 Aug 1996 15:22:29 -0400 (EDT)

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---------- Forwarded message ----------
Date: Thu, 1 Aug 1996 06:59:26 +0000
From: hwhitehe@is.dal.ca
To: Multiple recipients of list MARMAM <MARMAM@UVVM.BITNET>
Subject: US Navy Low Frequency Active Sonar

From: Hal Whitehead

            Low Frequency Active Sonar and Cetaceans

Given the task of killing as many of the world's cetaceans (whales
and dolphins) as possible, there are a number of options that should
be considered.  A huge PCB release would be quite effective, as
would a twenty-fold increase in drift-netting (for the smaller
species) coupled with intensive commercial whaling (for the larger ones).

Another option that should be seriously considered is the use of a
number of very intense mobile sound sources.  Cetaceans sense their
environment and communicate largely through sound.  They can be
easily disturbed and injured by loud noises.  A deaf whale or dolphin
is unlikely to survive for long or to reproduce effectively.  Sounds travel
particularly well in the ocean and so a very loud sou
rce can affect animals over a large range.  For maximum destructive
ability, the following design criteria should be considered:

        -  the source should be extremely loud (perhaps 250dB).
        -  it should operate at a frequency most cetaceans can hear,
 but low enough to have a substantial effective range (low frequency
  sounds travel especially well in the ocean).  A frequency of a few
  hundred hertz might be optimal.
        -  the source should be mobile so that concentrations of Cetaceans
all around the world can be targeted.
        -  the system should be operated by an agency with the ability to
deploy a number of these systems simultaneously and quickly where needed.
        -  if this agency can keep its operations secret from the radical
environmentalists who wish to protect cetaceans and other ocean life, so much
 the better.

A slight drawback of this plan is that our understanding of the
effects of sound on cetaceans is rather limited, so the effectiveness of these
sound sources in destroying cetacean populations cannot
be predicted accurately.  However, there is a fair likelihood that
they will be very effective.  Added benefits include the debilitation of other m
arine
 creatures, and the detection of submarines.

Therefore, for anyone interested in the destruction of cetaceans and
other ocean life I recommend a serious consideration the United States Navy's Lo
w
Frequency Active Sonar Program, which, according
to the limited information available, seems to meet these design
criteria.

Hal Whitehead,
Department of Biology,
Dalhousie University
HWHITEHE@IS.DAL.CA

31 July 1996