Scientists in the environmental community know intense sonar kills marine mammals. Just ask the Spanish veterinarians who arrived on the Canary Islands just after a NATO naval exercise. They examined the stranding of 14 beaked whales. They found the mammals dying, severely shocked, and bleeding profusely from their mouths and eyes. The vets did a full carcass examination and found severe hemorrhaging around the brains and also around the blood vessels of many of the other organs. They found gas and fat bubbles in their blood consistent with a case of the "bends" or too rapid decompression according to an article by Peter Canby in NRDC's magazine's On Earth. The investigators suggested the whales were forced to the surface too rapidly by intense sonar waves from practicing warships. Faced with cranial hemorrhaging evidence from an earlier Bahama stranding of 17 beaked whales, the Navy concluded the mammals died from "cardiovascular collapse" after stranding. A conclusion strongly disputed by the scientists who performed necropsies on several of the cetaceans' heads.
But such anecdotal evidence is not enough for the US Navy to avoid using intense sonar around whales. It has been doing hearing loss research on marine mammals for 15 years, but because it wants to use active sonar systems emitting extremely intense sonar waves, Navy funded research focuses obsessively on controlled exposure to sonar. Its funding of such research is intended to provide justifications for continued use of sonar near marine mammals. The NRDC found evidence of this biased approach when a series of e-mails was discovered in the course of a lawsuit against a proposed deployment of low-frequency sonar. The Navy's environmental manager for the system asked a Navy funded researcher if a negative environmental appraisal was issued by Navy funded scientists. When told that they were receiving Navy research funds, the manager told the researcher their appraisal comments were "....were out of the box. If they are funded by the Navy, the proper way to bitch is via the sponsor (you)." The Navy is not above pressuring researchers whose universities are heavily dependant on government funding. Getting funding is a matter of career success or failure for many. When the Navy does not like the results, it simply stops participating, as it did when an attempt at a consensus report to guide Congress failed. The Office of Chief of Naval Operations called the scientific panel and told them it no longer agreed with any of the draft consensus report. The consensus process collapsed and only sharply different caucus reports were issued. When you work for the Navy its their way or not at all.