Eavesdropping on whales to avoid ship strikes

By Jay Lindsay

updated 10:43 a.m. ET May 7, 2008

ON CAPE COD BAY, Mass. - A spotter bangs three times on the boat's cabin roof, signaling the captain to cut the throttle — now.

In the foggy gray of Cape Cod Bay, the reason for the abrupt stop soon becomes apparent: The research vessel is surrounded by rare North Atlantic right whales, their glossy black heads bobbing just above the surface as they feed on plankton slicks.

Ship strikes are the top human-related cause of death for these mammals, which are in danger even from this vessel, a slow-moving research boat called the Shearwater. But new technology could soon help safeguard the whales by using sound, not sight, to track the creatures' movements.

"We're listening to their chatter," whale expert Christopher Clark said aboard the Shearwater, referring to the grunts and groans whales use to communicate. "They can't keep their mouths shut."

In the past, tracking whales often depended on inefficient aerial surveys, which were limited by weather and how often the whales surfaced.

Now researchers listen for the whales using 13 underwater microphones attached to buoys off the coast of New England. Eventually, scientists hope to follow their movements closely enough so boats can slow down and post lookouts.

"The slower the ships go, the lower the risk of killing a whale with a ship," said Clark, director of the bioacoustics research program at the Cornell Lab of Ornithology, and the project's lead scientist.

Hearing, not seeing whales
Kathy Metcalf of the Chamber of Shipping of America said shippers would welcome a listening system because they are currently being asked to reduce their speed despite uncertainties about where the whales actually are.

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"We've been saying all along that if we can get real-time information, we want to avoid them," Metcalf said.

The right whale was hunted nearly to extinction in the late 18th century, and the death of even one in the estimated population of 350 to 400 is a setback. Since 1986, at least 32 right whales have been killed by ships.

The slow-moving whale is oblivious to its surroundings while feeding and is frequently at risk while migrating up and down the East Coast through busy shipping lanes and waters laced with fishing gear in which it can get tangled.

Clark got the idea after a chat in 2001 with fellow whale researcher Moira Brown, who wondered if they could record the whales in Cape Cod Bay and then match the sounds with what scientists were seeing.

Clark was shocked to hear the tape loaded with calls even when no one knew whales were present. He started recording more frequently in larger areas and discovered the whales were always around, even when the planes spotted nothing.

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