Quiet Autonomous Gliders Promise “New Era” in Acoustic Monitoring – A major step forward in acoustic monitoring has passed its first test. “We are entering a new era of underwater sensing,” says Jim Theriault of Defence Research and Development Canada, in Dartmouth, Nova Scotia, who ran the first trial of small torpedo-shaped “gliders” as a platform for acoustic monitoring. Unlike other systems, which require a boat nearby to monitor either the tagging of whales or other autonomous vehicles, the gliders can use a satellite phone connection to return data to distant research bases. Also, the new system has enough data capability to detect not only low-frequency baleen whale calls, but also the high-frequency calls of sperm and beaked whales, deep-diving species of special concern in sonar studies (there are some indications that sonar signals can disrupt their natural dive patterns, perhaps causing injuries due to surfacing too quickly or not having enough time at the surface between dives). Peter Liss from the University of East Anglia in Norwich, U.K., chairman of the U.K. government’s Inter-Agency Committee on Marine Science and Technology suggests that these gliders could be used in research to finally pin down whether noise does actually upset whales. “The link is probably there, but rather tentative,” he says. Since the glider is quiet and isn’t being followed at a close distance by a noisy ship, it should be able to gather the data needed to prove—or disprove—a link between sonar and whale strandings, he suggests. The glider being trialed runs on batteries and can last up to a month. But plans are afoot to make a low-power glider that can prowl the oceans for up to five years. Source: Conservation Biology, Oct-Dec 07 [READ ARTICLE]