According to Knowlton, 25 of the 71 right whale deaths reported since 1970 resulted from ship strikes.
"A speed limit will give the whales a little more time to react to ships and successfully get away," Knowlton said.
"It will help prevent several mortalities annually, and over time that will be a huge benefit to the overall population."
Other marine wildlife experts agree.
"This measure isn't expected to give ships time to spot and avoid whales," said Karen Baragona, a whale and dolphin specialist with WWF, the international conservation organization.
"It's intended to give these relatively slow-moving whales a little extra time to react to and swim away from an oncoming ship."
WWF has been working with the New England Aquarium and the shipping industry to encourage ships to avoid an area in eastern Canada called Roseway Basin.
Right whales spend part of each summer feeding and raising their calves in this region (related photo: southern right whale and her calf). Every death from a ship collision has a grave impact on future generations, Baragona says, especially if the whale is a female.
"By this token, saving just a few females each yearbecause of the exponential contribution to future generations of right whalescould put the species squarely on the road to recovery."
Members of the shipping industry, however, are not sure the new speed limit will decrease whale deaths.
Don O'Hare is vice president of the World Shipping Council, a lobbying group based in Washington, D.C.
"We have worked closely with the government to protect whales, but they have not convinced us that reducing the speed of ships will save the whales," he said.
He points to data collected by federal agencies that show the U.S. Navy and Coast Guard are responsible for 24 percent of all ship strikes on whales between 1975 and 2002.
Federal ships "are not required to reduce their speed under this rule," he noted.
O'Hare also says the new plan doesn't factor in hydrodynamic data on how boats churn seawater at various speeds, which had been previously promised.
NOAA's Wieting acknowledges that hydrodynamic studies are still being conducted, but, she says, the plan does include computer simulations instead.
And while government ships would be exempt from the proposed rule, they are still responsible for protecting the whales under the Endangered Species Act, she notes.
The plan will go through a two-month period of public comment before any final decision is made.
"If all goes well, we could see a drastic reduction in the number of whale mortalities from ship strikes," Wieting added.
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