Sound and Fury
Whale deaths blamed on sonar have triggered a heated debate about man-made noise in the sea
Whale biologist Ken Balcomb always gave what he calls the "standard disclaimer" to the Earthwatch volunteers who would come to the Bahamas to help him and his collaborator and wife, Diane Claridge, study Cuvier's beaked whales. The animals are elusive, he would warn them, usually over morning coffee at the beach house he and Claridge rented each season. The odds were pretty slim that they would spot one of these small whales during their 10-day visit. But on March 15, 2000, before the new crew had even heard the disclaimer, they'd seen their first beaked whale.
"Ken, come quick!" shouted a research assistant who'd gone out for an early-morning walk. As Balcomb and Claridge ran down to the beach they could see a young whale stuck in the sand around its midsection, still sweeping its tail up and down, as if to complete its suicide run up onto dry land. The tide was dropping, so Balcomb, Claridge, and their Earthwatch crew got to work quickly, pivoting the 16-foot creature and then, with each wave, nudging it deeper into the water. Once freed, it swam strongly out to sea. But before they could raise a cheer, the whale turned and headed back to the beach. Balcomb and his team had plunged back in the water to try to herd the whale out to sea again when a local fisherman came by with the news that another whale had beached itself a mile and a half down the shore. Then a frantic neighbor called, asking to borrow a sea kayak--he, too, had been trying to keep a disoriented whale off the sand. And so it went all day long.
In the end, a total of 14 beaked whales, along with two minke whales and a spotted dolphin, ran aground across a hundred miles of Bahamas coast. Seven are known to have died. The shy, deep-diving beaked whales have met similar sad ends on beaches worldwide, from the Galapagos Islands and the Lesser Antilles to Corsica and Greece. In September, a pair of beaked whales came ashore in the Gulf of California, and 15 in the Canary Islands, off northwest Africa. And while so-called strandings of other kinds of whales are common, they are usually blamed on disorientation and illness. In this case, the cause is suspected to be man-made noise.
In the Bahamas, the whales flopped up onto Balcomb's doorstep while, offshore, the U.S. Navy was conducting exercises with powerful sonars. In the Canaries, a multinational fleet comprising at least 58 boats and six submarines was engaged in maneuvers when the whales began fleeing the sea. In the Gulf of California, a seismic research vessel towing an array of air guns was probing the Earth's crust with powerful pulses of low-frequency sound. In fact, many mass strandings involving beaked whales in recent decades appear to be linked to sources of loud sound in the ocean, says Charlie Potter, an expert on marine mammal strandings at the Smithsonian Institution in Washington, D.C. The incidents have fed an increasingly raucous debate about the threat posed to whales and other marine mammals by all sorts of noisy machines at work in the oceans--from supertankers and cruise ships to oil rigs.
advertisement
