Using a system of underwater hydrophones that can record sounds from hundreds of miles away, a team of scientists has documented the presence of endangered North Atlantic right whales in an area they were thought to be extinct.
The discovery is particularly important, researchers say, because it is in an area that may be opened to shipping if the melting of polar ice continues, as expected.
Results of the study were presented this week at a meeting of the Acoustical Society of America.
The scientists from Oregon State University and the National Oceanic and Atmospheric Administration are unsure of exactly how many whales were in the region, which is off the southern tip of Greenland and site of an important 19th-century whaling area called Cape Farewell Ground. But they recorded more than 2000 right whale vocalizations in the region from July to December of 2007.
“The technology has enabled us to identify an important unstudied habitat for endangered right whales and raises the possibility that – contrary to general belief – a remnant of a central or eastern Atlantic stock of right whales still exists and might be viable,” said David Mellinger, chief scientist of the project.
“We don’t know how many right whales there were in the area,” Mellinger added. “They aren’t individually distinctive in their vocalizations. But we did hear right whales at three widely space sites on the same day, so the absolute minimum is three. Even that number is significant because the entire population is estimated to be only 300 to 400 whales.”
Only two right whales have been sighted in the last 50 years at Cape Farewell Ground, where they had been hunted to near extinction prior to the adoption of protective measures.
The pattern of recorded calls suggests that the whales moved from the southwest portion of the region in a northeasterly direction in late July, and then returned in September – putting them directly where proposed future shipping lanes would be likely.
Right whales are the most endangered large whale and vulnerable to collisions with ships as they ignore general ship sounds. Alarm sirens intended to scare them away from ships may actually be more likely to cause a collision, as the whales have been shown to rush to the surface when they hear the alarm.
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