My name is Dr. Linda Weilgart, and I am a research associate in the Dept. of Biology, Dalhousie University, Halifax, Nova Scotia, Canada. I have spent the last 16 yrs. studying the vocalizations of whales. My Master's, Ph.D., and post-doctoral research all were in the area of whale communication. I, together with my husband, Dr. Hal Whitehead, have probably spent more time with sperm whales at sea than any other scientist.
I am opposed to the use of LFA (Low Frequency Active) sonar in Hawaiian waters, even if it is used to clarify the reactions of marine mammals to this noise, for the following reasons:
1) Based on several studies of large whales, the figure of 120 dB (re 1 microPascal re 1 m) emerges with startling consistency, especially given the huge behavioral variability these animals exhibit in the wild and the great difficulty we have in studying these free-ranging animals. Not only do grey and bowhead whales clearly avoid sounds at an *average* received intensity of 120 dB, but several fish species do as well. This evidence should be enough to give us pause. LFA sonar would cover an area greater than the size of Texas with sounds AT LEAST as loud as 120 dB, thereby placing marine life at risk for harassment over this huge area.
2) To place marine life at risk over such an enormous spatial scale would seem unconscionable, but to moreover place *breeding* whales at risk seems outrageous. You are not only endangering the animals present, but the welfare of future generations as well. Particularly when it is well-known that the humpback whale song plays a crucial part in mating, it seems nothing short of reckless to change their acoustic environment so drastically. The research of Phase I and Phase II did not focus on breeding animals, like Phase III does. Breeding humpbacks are not only mating, but they are giving birth to calves at the same time. It is quite likely that young animals are more sensitive to loud noises, and it is entirely plausible that unnatural acoustic disturbances to which these animals are not adapted, could interfere with the crucial mother-calf bond. Past research on the effects of noise in the grey whale calving lagoons has shown that mothers and calves cleared out of noisy lagoons for periods of months. Most disturbingly, this abandonment of some traditional calving lagoons due to noise resulted in a subsequent dramatically lower number of calves born that year.
3) My understanding from the papers presented at the World Marine Mammal Conference in Monaco and from personal communication is that Phase I and Phase II have already shown significant reactions to the LFA sonar noise by both grey and blue whales. How much more information is Phase III really going to add to this? At which point are all scientists and policy makers going to be convinced of the harmful effects of LFA sonar? And will there still be marine life alive in our seas when this point is reached?
Phase II, because it was studying migrating grey whales, had the greatest likelihood of discovering real effects of the LFA sonar on whales. This is because it exposed huge numbers (much of the Pacific population of grey whales) of un-habituated, novel animals to the LFA sonar transmissions. Much of the unpredictability and variability that usually plagues whale research at sea was eliminated because grey whale migration routes along the Pacific U.S. coast are well-known and unchanging. When LFA sonar was transmitting, grey whales clearly altered their course kilometers in advance of the sound sources. Moreover, the whales showed a significantly stronger response at source levels greater than 170 dB than would be expected if they were reacting in a linear fashion. This means that the louder the noise, not only the stronger the reaction, but the MUCH stronger the reaction. How much more evidence of harrassment is necessary?
Phase I also showed that LFA sonar transmissions seem to decrease blue whale vocalizations. Since we are unsure of the function these vocalizations fulfill in the lives of blue whales, it is unknown what the ramifications of fewer vocalizations might be. The most likely function of blue whale sounds has to do with mating, however. As blue whales are generally solitary animals, it is generally thought that blue whales vocalize to attract and find mates. Interference with their vocalization rates, in this case, could result in a drop in their pregnancy rates with a resulting, long-term drop in population levels.
4) While the above effects of LFA sonar on whales can be surmised to be biologically relevant, they can not be proven to be so. I am opposed to using LFA sonar to study its effects on whales for precisely this reason. To study the health of a whale population, one must have a clear understanding of population parameters such as fertility rates, mortality rates and growth rates for that population. These are practically impossible to determine with any accuracy for any free-ranging whale population. We have no idea what "normal" population parameters are for any whale species, and we certainly don't have any idea of whether these parameters might be changing as a result of LFA sonar transmissions. While studies such as Phase I and II may be worthwhile in studying the short-term reactions of several animals of a particular species at a particular time in a particular condition, these studies cannot be extrapolated to give us any idea of the long-term effects LFA sonar might have on the welfare of populations of many different species. In conclusion, the studies that are being done on whales to determine their reactions to LFA sonar are completely incapable of telling us what the effects of such noise might be on the welfare, especially long-term, of any population of whale.
The marine mammal research that is being done by the ATOC project (by some of the very same scientists involved in the marine mammal LFA sonar research) is being rendered somewhat useless for this very reason. Even though the research has clearly shown that sperm whales avoid the ATOC speaker, the chief scientists for the ATOC marine mammal project argue that this effect is not "biologically significant." This provides a permanent and convenient "out," as biological significance is unknowable for whale populations.
5) Not only the whales, but the whale-watching industry would be threatened by LFA sonar transmissions.
I urge you to stop LFA sonar transmissions in Hawaii and elsewhere, and to recognize that our marine heritage and resource is too valuable to gamble with.
Sincerely,
Linda S. Weilgart, Ph.D., Research Associate, Dept. of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada
Ph: (902) 494-3723
Fax: (902) 494-3736
E-mail: HWHITEHE@IS.DAL.CA
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Last Updated April, 1998 by Sascha Hooker |