A group of top whale researchers is arguing that the U.S. National Oceanic and Atmospheric Administration NOAA should reexamine a major regulation designed to reduce collisions between ships and highly endangered North Atlantic right whales. New research, they say, emphasizes that the current zones of speed limits are not as extensive as they should be. NOAA says it is already beginning to evaluate the effectiveness of the regulation.
Only about 300 to 400 right whales (Eubalaena glacialis) still ply the waters of the North Atlantic. As they migrate up and down the eastern coast of North America, passing many major ports, some whales get tangled in fishing gear and others occasionally get hit by ships. Experts say these risks threaten the survival of the species.
In 2006, NOAA's National Marine Fisheries Service proposed to set a 10-knot speed limit for ships travelling within 56 kilometers (30 nautical miles) of major ports, so that any collisions would be less likely to kill whales. The agency based its recommendation on a database of right whale sightings. But after objections from the shipping industry, the agency settled on a buffer zone of 37 kilometers (20 nautical miles).
In the new paper, a group led by Rob Shick, a postdoc at Duke University in Durham, North Carolina, examined different data—locations of two female right whales tracked by satellite in 2000 as they migrated along the eastern seaboard. The whales sometimes swam further than 37 kilometers offshore. They team used a statistical model to figure out what depth of water and distance from shore the whales seemed to prefer. Bottom line: "There's a larger swath of suitable habitat than previous thought," Shick says. The paper was published online in the Canadian Journal of Fisheries and Aquatic Sciences on 14 August.
"It's giving a little more evidence that the breadth of the migratory corridor might be quite a bit wider than thought," says Amy Knowlton of the New England Aquarium in Boston, who was not involved in the analysis. "I have always advocated for the 30 mile buffer and feel the evidence offered by Shick et al.'s work further justifies this broader boundary."
Greg Silber, NOAA's coordinator of recovery efforts for whales, says the agency is already preparing for possible changes, because the regulation was put in place with an unusual caveat: the rule phases out after 5 years unless it's been shown to be effective at protecting whales. Depending on what that analysis finds, the boundaries of the speed limits could be adjusted.
Photo Credit: NOAA