In September, more than a dozen whales beached themselves in the Canary Islands. Rescuers tried to water down the whales and keep them cool. But all of them 1 died.
Nearby, NATO naval forces were 2 echo sounding devices meant to 3 an enemy"s submarines, and public 4 of the deaths ultimately came to 5 suspicions of a link between whale distress and loud ocean noises.
The theory is 6 the mammals seek to 7 the roar of the deep, rush toward the surface and in some cases end up going ashore.
For decades, environmentalists have worked to reduce the undersea noise—usually with 8 success, given the growing industrialization and militarization of the oceans. They have 9 suits and waged letter-writing campaigns, 10 a recent petition that asks the United States Navy to 11 its testing of underwater sound equipment.
The discovery by biologists in Hawaii that whales can 12 the sensitivity of their hearing to protect their ears from loud noise 13 another dimension to the debate.
Michael Jasny, a senior policy analyst, called the research fascinating and said he hoped it would prove 14 in protecting whale hearing from these threats.
But he 15 the finding as a work in 16 that posed many unanswered questions.
"A lot more work needs 17 ," he said. "Could it be replicated in the wild It"s a huge question."
18 whales could learn to decrease the sensitivity of their hearing, Mr. Jasny said, that would 19 only a relatively small part of the oceanic noise problem. "It"s important to understand that it"s 20 ," he said of the proposed method. "It won"t be a silver bullet."