A long-standing mystery in marine biology is whether whales suffer from decompression sickness, a.k.a. the bends, after rapidly rising from the ocean depths. Biologists worked on the assumption the creatures were immune, but recent reports of beaked whales suffering acute bendslike symptoms after military sonar exposure raised the question anew. Now researchers from the Woods Hole Oceanographic Institution have examined 16 sperm whale skeletons collected since 1870 and found pockmarks and erosion in the bones of adult whales. The damage worsened with age and is consistent with the kind of bone injury that deep-sea divers suffer. If the bends is the culprit, whales have likely evolved behaviors to avoid the malady, such as gradual surfacing, says study co-author Michael Moore, and stressors such as sonar could sicken whales if they disrupt those behaviors. The study surfaced in the December 24, 2004, Science.