Just a few more miles or a few more minutes. That’s what scientists and some federal managers think it would take to improve the plight of the highly endangered North Atlantic right whale.
No more than 350 survive, and ship strikes are a leading cause of death for the whales, which live near and migrate through high-traffic coastal waters. Researchers are proposing that the U.S. government adjust shipping lanes around some ports and slow ships in other East Coast waters.
The “ship-strike reduction strategy” would reroute ships away from key breeding and feeding grounds; in other places, it would establish seasonal speed limits within 30 miles of the coast, perhaps slowing ships to 12 knots, about half the normal speed of many container ships and cruise ships.
The U.S. National Marine Fisheries Service announced in June that it intends to prepare an environmental impact statement as part of the process of implementing new shipping regulations. Conservationists and some researchers say the measure is long overdue; some maritime interests say the plan has as many potential negative impacts as positive ones.
For instance, shifting ship traffic closer to the coast could reduce the risk of a ship striking a right whale in Cape Cod Bay by 40 percent, said Hauke Kite-Powell, a research specialist in the WHOI Marine Policy Center (MPC) who recently delivered a research report on the matter to the Provincetown Center for Coastal Studies. For nearly five months a year, a significant number of northern right whales congregate in the nutrient-rich waters of Cape Cod Bay, Massachusetts Bay, and the Gulf of Maine. Hundreds of vessels pass through the area each year, making it likely that several ship-whale encounters take place annually.
Kite-Powell is now working with Amy Knowlton and Moira Brown of New England Aquarium (NEAq) to study how right whales respond to ships and how changes in ship speed might increase the odds that ships or whales could get out of the way. He also has worked with MPC colleague Porter Hoagland to study the economics of ship-strike management.
“If there is a reasonable place to move the shipping lanes—as Canadian managers recently did in the Bay of Fundy—then it makes sense,” said Kite-Powell. “It also could make sense in Cape Cod Bay. But for most of the East Coast, there is no good way to reroute ships. Speed limits might be the only way forward in the near term.”
Changing the shipping regulations would likely increase costs by $10 million to $15 million per year for commercial operators. But Kite-Powell points out that the changes could disproportionately affect certain ports, such as Boston, which has right whales crowding its shipping lanes for nearly five months a year.
In related research, WHOI biologists Hal Caswell and Michael Moore, NEAq scientist Scott Kraus, and 11 other researchers reported in the July 22 issue of the journal Science that ship strikes and fishing gear entanglements are killing North Atlantic right whales at a rate exceeding a level that allows the population to grow. In a statistical analysis and call for action, the researchers noted that the situation may be more dire than they can observe directly, with many whales dying out at sea and out of sight.
Ship strikes threaten the survival of the North Atlantic right whale. (Photo by Regina Campbell-Malone, Woods Hole Oceanographic Institution)
Endangered right whales congregate in Cape Cod Bay, particularly from December through May, while an average of seven passenger or cargo vessels pass through the area each day. Using five years of data on right whale sightings (red indicates more frequent sightings), researchers have proposed seasonal changes to shipping lanes to reduce ship-whale collisions. Solid lines indicate current shipping routes; dotted lines represent proposed, whale-friendly routes. (Illustration by Jayne Doucette, WHOI)