New Theory on High Power Military Sonar Effects on Cetaceans

6th Mar 2001 Mr. J.S. Johnson

Attn: SURTASS LFA Sonar OEIS/EIS Program Manager

901 North Stuart Street, Suite 708

Arlington, VA 22203

Dear Mr. Johnson:

Thank you for sending a copy of the Final Overseas Environmental Impact Statement and Environmental Impact Statement for Surveillance Towed Array Sensor System Low Frequency Active (SURTASS LFA) Sonar. Since my comments to you on the Draft OEIS/EIS (O-26; Balcomb, November 12, 1999), I have had the unique opportunity to witness and study a mass stranding of whales and a dolphin caused by a US Naval Sonar Exercise in the Bahamas (Pirie, ltr. June 15, 2000). That incident unequivocally demonstrated the lethality of high-powered sonars, and it provided the opportunity to understand how sonar has been inadvertently killing whales in vast expanses of ocean around the world.

The killing is largely due to resonance phenomena in the whales' cranial airspaces that are tearing apart delicate tissues around the brains and ears. This is an entirely separate issue from auditory thresholds and traumas that the Navy has fixated upon. In my earlier comments, I questioned whether there might be a problem with injurious resonance phenomena created by the sonar system described in your OEIS/EIS; but, now I have seen the problem and can attest to the fact that there is massive injury to whales caused by sonar. This is not an exaggerated statement, and I am reasonably sure that the Navy knows that. Please allow me to explain what happens to the whales.

Resonance, as engineers well know, can dramatically contribute to shear forces that can be quite damaging - wings tear off airplanes, bridges gallop, and buildings collapse, etc. due to unanticipated resonance phenomena which can afterwards be explained by simple physics and mechanics. I wondered about tissue damage caused by resonance, and I specifically asked what the Navy calculations for lung resonance frequencies of a beaked whale were at various depths. [You sidestepped my question by responding generically to my comment with response 4-4.15]. Subsequent to my asking you about specific resonant frequencies and depths, I found that in 1998 NATO and the US Naval Undersea Warfare Center had already calculated the resonance frequency of airspaces in Cuvier's beaked whales (Ziphius cavirostris) to be about 290 Hz at 500 meters depth (page H2, SACLANTCEN M-133), which is almost precisely the middle frequency of LFA (100-500 Hz) described in your OEIS/EIS! That information is quite important, with specific reference to Technical Report 3 of your DOEIS/EIS, wherein there are several citations of Navy sponsored studies that clearly demonstrated vestibular dysfunction (eg. dizziness, vertigo) and lung hemorrhage, etc. in laboratory animals exposed to LFA at their lung resonance frequency. In other words, the Navy has sufficient information available to know there is at least theoretically a very serious problem to whales from LFA for even brief periods of time.

The scientific and medical literature contains numerous examples of hemorrhagic injuries and death occurring in humans when they are inadvertently exposed to loud sound, particularly at their lung (airspace) resonance frequency. Undoubtedly such damage could also be demonstrated as occurring to whales if they could be tested and did not sink to the bottom of the ocean when they die.

The NATO report I referred to for resonance calculations was concerning the mass stranding of at least twelve Cuvier's beaked whales in Greece on 12 May, 1996 coincident with a NATO acoustic trial employing both LFA (450-700 Hz) and mid-frequency sonar (2.8-3.3 kHz). Superficially, in reading that report one might wonder whether either frequency range "caused" the whales to strand in Greece, since neither matched the reported resonance frequency in that instance for Cuvier's beaked whales' airspaces at an arbitrarily chosen 500 meters depth. However, also in that NATO report there were formulae of Minn

You are welcome to share or use information and articles from this website but please reference the source and acknowledge the IWDG.