Two new studies have uncovered what the Guardian is terming a "missing link" between sonar and whale strandings. Though the advent of military sonar in the 1950s coincided with a spike in strandings, one of the researchers involved explains that an unknown piece of the puzzle has been how—and even whether—whales respond to the noise. In one study off Southern California, a simulated military sonar signal was sounded at levels well below the military's threshold, at distances between roughly 2 and 6 miles from two beaked whales that had been studded with suction cups; that particular species was chosen because it is most regularly the victim of mass strandings.
The result: The whales first stopped feeding (and didn't resume eating for as long as seven hours, which is unusual) and swimming, then high-tailed it away from the noise and were observed to have taken longer dives. A second study in the same region suggested that blue whales' feeding was similarly disrupted; a creature lost the equivalent of a day's meal, which a researcher says could "have significant and previously undocumented impacts" on the animals' health. But he called the responses "complex," with PhysOrg noting that not all the whales reacted in the same way—and some didn't react at all. The US Navy provided funding for the studies, which it points out only concern behavior, not any eventual harm. (In other fascinating whale news, scientists have figured out how the creatures can hold their breath underwater.)