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Known to be very sensitive to sound, a means of both communication and navigation, whales have only in recent decades stranded themselves. The incidents correlate with a technological change in the world’s navies. That change was a move away from passive listening sonar to active sonar. Active sonar bounces sound off approaching submarines. By the 1980’s the new silent subs were difficult to hear with passive sonar, and navies dramatically increased experiments with active sonar. It is this high intensity sound in water that is impacting whales, according to marine biologists. Two researchers from one of the world’s leading marine research centers at Dalhousie University in Halifax, Nova Scotia, have developed innovative techniques for studying whales. Hal Whitehead and his wife Linda Weilgart have said the evidence of the deadly effects of sonar on whales is clear. The oil and gas industry also use sonar in searching sea beds for deposits. The U.S. Navy (70% of marine mammal research in U.S. and 50% worldwide) and the energy industry provide many of the whale study grants. Whitehead has said that many of his colleagues, as a part of their university jobs, spend 50% of their time chasing grant money, and this can have corrupting effects. The Navy’s need for sonar is obvious, as are its public relations concerns over its impact on whales. When active sonar exercises increased, more whales were found stranded in the exercise areas. In 2001 the navy and NOAA were pressed into acknowledging that navy sonar was the most plausible source of the trauma that led to the deaths of the whales. Autopsies of some beached whales revealed symptoms much like an extreme version of the bends. Divers who surface too quickly from deep water develop the bends from nitrogen forced into muscle tissue, a painful condition which can be fatal. The navy had acknowledged the likelihood that sonar was the cause of the whale deaths. However, after a two-year struggle over the details of the language for a consensus report that Congress could use as a guideline for making decisions on marine-acoustic issues finally collapsed. The Navy statement on the collapse said the navy no longer agreed with a single line in the draft consensus. Whitehead in 2003 presented a paper in which he described navy funded research as narrow-minded, frequently wrong and suffering from conflict of interest. All of this has done nothing for the whales. Noise levels in the ocean are known to be dramatically higher than 50 years ago. Increased shipping traffic, larger more powerful ships, sea floor exploration, high speed torpedoes and submarines have all made life difficult for whales. |
