Whales' Plight Revives Sonar Theory

With interest and research growing, new reports strongly suggest that traditional sonar has caused many more mass strandings than previously believed. A database of known beaked whale strandings and naval maneuvers put together by James Mead of the Smithsonian Institution marine mammal program has found an overlap of "between 100 and 200 cases" in the past four decades. He said the overlap does not prove sonar caused the strandings, but "the association certainly is quite impressive."

Just this month, Robert L. Brownell Jr. of NOAA in California presented a paper at the International Whaling Commission that examined beaked whale strandings since 1960 near a U.S. naval base in Japan. He found evidence of at least 10 mass strandings -- involving between two and 13 animals -- in the waters near the naval base at Yokosuka. For comparison, Brownell examined records for the coast of New Zealand and other areas off Japan and found no indication of mass strandings in either locale.

"The co-occurrence of the mass strandings and the U.S. Navy activity in this region strongly suggests" a relationship, Brownell concluded.

Although the Navy has used "active" sonar -- whereby ships send out sound to bounce off underwater objects -- since World War II, the power of that mid-frequency sonar has increased over the years. The apparent link between this type of sonar and major whale strandings is a relatively new discovery, and it has put the Navy on the defensive. Several hours into the recent Hawaii incident, NOAA officials asked the Navy to stop its sonar exercise -- which included two U.S. and four Japanese ships -- and the commanders complied.

Navy officials say the service is the primary environmental steward of the world's oceans, funding 70 percent of marine mammal research in the United States and almost 50 percent worldwide. Officials also say that the number of sonar-related incidents is small, though worrisome.

Rear Adm. Steven Tomaszeski, the Navy's chief oceanographer and for 30 years a Navy combat officer, said the seamen involved in the Bahamas stranding in 2000, for instance, "told us they felt really terrible about what happened to the whales. But, the truth is, we just didn't properly consider that they might be there."

"We actually know more about the surface of the moon than we know about our oceans," he continued. "We don't really know where many of the whales are, and we don't know too much about how a whale's ear works. Some would say that if you don't know, then don't take chances and let's keep our acoustic energy out of the water. It's the precautionary principle. But in good conscience, I couldn't send a fleet out to sea without sonar. It's the best anti-submarine defense by far."

To be effective, however, the sonar systems need trained sonar operators, and Tomaszeski said that requires on-the-water experience. Training maneuvers occur regularly around the world, he said, and a sonar training exercise brought the Navy into contact with whales in the Bahamas in 2000, the Canary Islands in 2002 and, apparently, off Hawaii this month.

Whale advocates and environmentalists say they fully understand that sonar has to be used without restraint in times of war. The training exercises, they say, are needlessly harmful.

Environmentalists familiar with the plan for a shallow-water sonar testing range say the Navy should expect opposition to the proposal. According to Donald Schregardus, deputy assistant secretary of the Navy for the environment, planning began about four years ago. He said the Navy wants to install underwater microphones and sensors to create a facility where sailors can better train to use sonar.

He said the Navy is working with federal environmental officials to study which animals inhabit or migrate through the area and at what times and densities, and to assess the likelihood of disturbing marine mammals.

"We want to improve underwater training and detection," Schregardus said. "And we want to take that knowledge and information and establish a range on the West Coast, too."