Navy Sonar Is Causing the Bends in Marine Mammals, Report Says

Sonar from navy ships appears to be giving whales and other marine mammals the bends, that infamous bane of scuba divers and other deep-sea adventurers, according to a report published in the latest edition of the journal Nature. Researchers from England and Spain found air bubbles in tissues and blood vessels of whales that died in the Canary Islands shortly after a naval exercise in 2002; such bubbles are a sign of the bends, also known as decompression sickness. The researchers offered two hypotheses for how sonar induces the bends: Either it could cause the animals to panic and rise to the surface too quickly (the cause of the bends in humans), or it could directly cause bubble formation on gas nuclei in whale tissues. The findings could have major implications for the U.S. Navy’s ongoing efforts to gain approval for widespread use of very loud, low-frequency sonar, which is in the auditory range of some of the world’s largest and most endangered whales.