Cetacean Society International

Whales Alive!

Vol. VIII No. 4 October 1999

Respond To The LFA DEIS: Public Comment Period Closing 28 October 1999

By William Rossiter, CSI President

If you do nothing else for whales this month please use your one opportunity to comment on the U.S. Navy's Low Frequency Active Sonar Draft Environmental Impact Statement before the public comment period closes 28 October. Specific points from all the received comments must be addressed by the DEIS authors, who will then publish a Final EIS. If NMFS approves the FEIS the LFA will be allowed to operate, unless a court case intervenes. The FEIS will also be a Biological Assessment for NMFS. NMFS will issue a Biological Opinion that may include demands and changes but from much that we have seen recently from NMFS we do not expect much help for marine mammals. CSI has participated directly, tried to be objective and open minded, and we have given the Navy the benefit of the doubt again and again. We have spent a great deal of effort trying to understand and communicate this very confusing and complex issue. Frankly, it scares us. It should scare you too.

For three years Whales Alive! readers have plowed through the articles on the LFA in every issue. Why have we been so focused on the LFA? First, and most disconcerting, NMFS has failed to establish specific definitions of human noise impacts that would allow management strategies and regulations to be implemented. By default the LFA DEIS may be used for this purpose. Senseless as it seems, future regulations written to manage all harmful human noise in the ocean may be defined by a military contractor intent on selling a very loud product. Foxes should not be allowed to guard hen houses. To their credit NMFS has tried several times to get expert and specific definitions. When pressed the experts only agreed that we are all too ignorant of anthropogenic acoustical impacts to declare specific numbers. As one result the DEIS has used the highest numbers they can find to define the LFA's lowest mitigation threshold, and dismisses most caveats declaring ignorance and demanding caution. CSI's second concern with the DEIS is that it has the potential to do harm to the marine environment; the LFA is so loud that it can kill. Third, in spite of intuitive reasoning, there are so many unknowns about the significance of human noise in the oceans that any major source of objective data has enormous value. We therefore had high hopes for the associated Scientific Research Program (SRP) funded by the Navy to quantify human noise impacts on cetaceans. In retrospect it did not. Fourth, all the panels of experts convened by NMFS have made recommendations that are highly equivocal, laced with statements about unknown hearing threshold levels and ultimate effects of noise. They consistently argued for extreme caution in the face of ignorance. This is the Precautionary Principle, and it is missing altogether in the DEIS.

Now we ask you to act. Please send a letter or fax expressing your concerns by the 28 October deadline to: Mr. J. S. Johnson, Attn: SURTASS LFA Sonar OEIS/EIS Program Manager, 901 North Stuart Street, Suite 708, Arlington, VA 22203. Fax: 703-465-8420. Emails are not acceptable.

"The Draft Overseas Environmental Impact Statement and Environmental Impact Statement for Surveillance Towed Array Sensor System Low Frequency Active (SURTASS LFA) Sonar, Department of the Navy, Chief of Naval Operations, July 1999" is a lengthy, repetitive, assertive, unsubstantiated, misleading document. It purports to satisfy the legal requirements to enable the LFA to become operational, and that assertion will follow it to court. Over and over it says that "...no non-serious injuries are expected to occur and any taking would be infrequent, unavoidable, or accidental. The numbers of animals taken would be so small as to have a negligible impact on the affected species' stock and upon the availability of the species for subsistence needs". This ignores the default reality that the LFA EIS will become the new standard for "acceptable" sound impacts for every noise polluter.

The LFA is a complex system designed to locate the super-quiet submarines that older sonars cannot find. Many military professionals consider the system to be of little practical use. To start with, it is very vulnerable. While announcing itself to anything within hundreds of miles it can only work at 3 knots, and it cannot turn easily while transmitting. A Vertical Line Array of 18 projectors will transmit combined sequences of hums, sweeps or continuous frequencies for 6-100 seconds (even a 100 second sequence is euphemistically called a "ping") between 100-500 Hz. Intervals between signals are nominally 6-15 minutes while echoes return, for a duty cycle of 10-20%. In a challenging military scenario the LFA might transmit continuously from ten to 24 hours, resulting in 100 "pings" or more. The cumulative effect of repeated sounds is known to magnify acoustical impacts.

The fundamental flaw in the DEIS is establishing the outside threshold for mitigations at the point where a marine animal would receive 180 dB re 1 µPa (rms), the term for the point at which the DEIS allows that 95% of the large whales would suffer "non-injurious harassment". This definition is a DEIS invention, and far louder than most experts would agree with. This term is meant to suggest that the DEIS complies with "Level B Harassment" as defined by the Marine Mammal Protection Act, but there is no basis for this. "Non-serious injury" is used where , for example, the DEIS assumes only transient effects like temporary deafness ("temporary threshold shift") at 180dB, in spite of conflicting expert views. Perhaps it is meant to be vague and confusing. Continuing the assumption, in a DEIS-conceived graph illustrating percentages as a "Risk Continuum", about 75% of marine animals receiving more than 170 dB would incur "non-injurious harassment", 50% at 165 dB, and only 2.5% at 150 dB.

The 180 dB field extends to 1 kilometer from the source, not surprisingly the most optimistic maximum mitigation zone. The Navy asserts that they can detect marine mammals and turtles within this zone using visual searches (the LFA operates also at night and in high seas), passive arrays (many species of concern do not make many sounds), and a modified fish finder sonar (very loud but untested) to locate even small turtles 1 kilometer away, or further away if they are approaching or in the LFA's path. When animals at risk are detected the LFA would not operate. Picture a massive naval operation involving hundreds of vessels pausing while a turtle swims far enough away from the LFA source. Picture the commanding admiral having a heart attack. Bow riding dolphins and the fish-finding sonar introduce problems of directed harassment. This HF/M3 sonar puts out 220 dB at 30 kHz (within the hearing range of many toothed whales) and accounts for 70% of the LFA's detection capacity. Any need to mitigate at received levels below 180 dB extends the mitigation zone beyond any hope of detecting animals under threat. But that's the Navy's problem, and a primary flaw in the DEIS.

What about marine life caught close to the LFA when transmissions start? "Ramp up" is a common mitigation for loud sound sources. Starting at below operational levels and increasing the signal strength over several transmissions may allow vulnerable species to vacate the area. Military systems designed for combat situations do not have the luxury of slowly warming up. Anything close to the LFA when it starts gets the full volume. Vaguely described as "nearly co-located with the LFA" is a zone within which an animal would suffer permanent deafness or death. This is dismissed in the DEIS presumably because few animals would be impacted. But the potential for one right whale to be under the LFA vessel and hit by a full force LFA signal was the probable motivation the Navy needed to declare much of the continental shelf East of North America off limits to LFA operations. They know one dead right whale is too many. The same rule does not apply elsewhere.

Where did the 180 dB level come from? Obscurely referenced in the DEIS it may have come from 1997's High Energy Seismic Survey workshop, where the expert panel concluded that "they were `apprehensive' about levels above 180 dB re 1 µPa (rms), with respect to the behavioral, physiological, and hearing effects on marine mammals in general." 180 dB was the level at which the HESS experts felt damage was likely to occur. Although they added that "the 180 dB radius ... is recommended as the safety zone distance to be used for all seismic surveys within the Southern California study area", it is vital to understand that seismic impulses are short bursts of sound that are thought to have less impact than equivalent received levels of continuous sound, like the LFA. As a rule experts might consider similar effects from continuous sounds at 10 dB below impulse values. For the LFA this means that 170 dB might be the threshold value, but 180 dB is not adequately substantiated.

75% of the exposed animals would still incur "non-injurious harassment", such as temporary deafness, receiving 170 dB. Assuming that that is somehow acceptable, how far away could they be to hear this level? The data in all LFA materials is referenced as "transmission loss", rather than received levels, because the full "Integrated Source Level" is classified. However, working backwards from the 180 dB at 1 km, the source level would be about 235 dB. From another perspective, while individual projectors are limited to 215 dB the full 18 projector array is, according to the DEIS, over 25 dB greater than that. This suggests that the LFA "integrated source level" is 240 dB. The complex physics of underwater acoustics also result in "beam forming" of the LFA sound. It can even be aimed, satisfying the Navy's need to get loud levels of sound out very long distances so subs can be located by concentrating the energy. Received levels are strongly affected by environmental circumstances. In warm waters the beam is refracted down and up in a wave that may be repeated well over 150 miles. In cold waters the beam does not refract as much, and might be caught in a "surface duct", losing so little power that some creature over 140 nm away would still receive 150 dB. 150 dB has been reported scientifically as having significant behavioral effects, but these are dismissed in the DEIS. The point is that at the very least the mitigation zone around the LFA source should be based on the maximum operational distance at which an appropriate threshold level is received. CSI argues that, according to all the experts, and an overwhelming need to invoke the Precautionary Principle to cushion our collective ignorance, 180 dB is far too loud to be considered as the beginning point of mitigations. The DEIS plainly argues that nothing need be done regarding LFA operations unless a marine animal is detected within 1 km, within which 180 dB would be received.

The effects of cumulative noise are also poorly known, but considered significant by all the experts. The DEIS does discuss 170 dB, in the context of a "single ping equivalent". Admitting that "there is a very limited basis for determining the potential effects of repeated exposures for marine mammals, ... (it is) postulated that the risk threshold is lowered by 5 dB for every ten-fold increase in the number of sounds in the exposure." Their example uses 100 pings at 170 dB as equal to 180 dB. During a full military exercise it may be likely to transmit 100 pings. The time this takes is not relevant. If 100 "pings" are received at 170 dB, and that is equivalent to a 180 dB impact then it is logical that the realistic mitigation zone must be equal to the range at which a marine animal would be exposed to a "single ping equivalent". Even if we allow 180 dB we must factor in cumulative impacts, and this extends the physical mitigation zone well beyond 1 km, perhaps as much as 40 km from the source for 170 dB "pings". The DEIS fails to do this based on a maximum number of pings scenario. If they argue that affected whales would likely swim away we would reply that in far too many cases whales have become too accommodated to human impacts, until it is suddenly and finally too late. Those that did flee might be forced from areas significant for reproduction, feeding, social cohesion, and migration. Again, the DEIS considers all behavioral effects irrelevant. The DEIS obscures the point that no matter how many creatures receive very loud LFA sounds, anything less than 180 dB of the LFA signal is dismissed; 180 dB is where mitigations start.

In error the DEIS dismisses the potential for large whales to be harmed by loud sounds because whales themselves make loud sounds. The mechanisms whales have for protecting their ears can "lock up" fragile structures, but they are designed for the whale's own noises; there is no evidence that they could use this to lessen the LFA's impact. Besides, while enduring an LFA transmission the whales are denied the use of natural sounds needed to avoid predators, maintain social groups, and find food and mates by "masking".

The DEIS uses the Scientific Research Program (SRP) as the basis for dismissing all previous scientific data that find significant impacts at received levels well below 180 dB, in fact down to 120 dB. One glaring omission is any data on any toothed whales. Again this was a Naval budgetary decision that limited the research potential of the Hawaiian SRP phase. The sperm whale is known to go silent and flee human sounds, suggesting impacts on feeding, reproduction, and social structures. Along with beaked and bottlenose whales, they are deep diving. The DEIS does discuss the extra impacts on deep divers, but ignores the sperm whale because the population numbers are relatively high; a number of deaths would not do enough harm. "Biological significance" is measured only as a high percentage of risk to a whole population; it does not count unless many will be killed.

The SRP is referenced in the back of the DEIS as Technical Report #1 (TR#1), an only slightly revised version of the "Quick Look" reports done after each SRP phase. The "Quick Looks" were not meant to stand as definitive science. If the TR is the only data available to DEIS authors it should be assumed to reflect additional and revised analyses. Nothing else is known to be publicly available for objective assessment. Unfortunately there are problems with chart labels, editing, wording and data presentation that leave reasonable reviewers wondering how some conclusions are reached. For example, in spite of being unable to get a reasonably constant received level to targeted singing humpbacks in Hawaii, the TR tries to extrapolate from a very small sample size, including individuals that never received levels over 130 dB, that most singing whales did not stop because of the LFA. Some examples do not clarify this conclusion, but rather leave a reviewer with several interpretations. In any case, if a whale stopped singing the TR makes an effort to dismiss the LFA as the cause. The language used is in stark contrast to the cautious, deliberate wording of draft protocols and permit requests for the SRP. One is also left to wonder why the Hawaiian phase was scheduled over a known period of significant premigratory redistributions of the humpbacks near Hawaii, leaving enormous and unanswered allegations that the LFA was a partial cause for whales moving away. There were no associated surveys before, during and after the LFA that would have allowed adequate and independent judgment of the LFA. Observations were based on single, targeted whales, not the overall population that could hear the LFA at levels of 140 or 120 dB. There were aerial surveys but these were not coordinated with LFA operations and leave so many questions unanswered that they are also being used in a legal case that argues that many whales left the area. All of these limits are the result of budget limits imposed by the Navy that ultimately leave too many results in question. In addition there were a considerable number of anecdotal comments from Hawaiian locals knowledgeable about "their" whales that were never presented and formatted to fit into the SRP analysis. They are simply dismissed.

While we plead with you to write a comment letter on this LFA DEIS we know that we are not making it easy. The general rule is that environmental groups seeking public participation must write a sample letter with all the points you should say. We think that is insulting you. We have tried to give reasons for concern with the LFA. We know that you are concerned for cetaceans. Please write a strong letter by the deadline. You won't have another chance.

Go to next article: First Annual Silent Oceans Day or: Table of Contents.

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