Protection efforts for the critically endangered North Atlantic right whales got a boost Monday when federal fisheries officials announced that speed limits for ships in designated areas along the eastern seaboard will become permanent.

The rules to limit ship speed were adopted by the National Oceanic and Atmospheric Administration in 2008 and were due to expire on Dec. 9. But NOAA announced Monday that it had removed the so-called sunset clause. "These effective protections for North Atlantic right whales will continue aiding their recovery," NOAA said in a press release.

The regulations restrict vessel speed to no more than 10 knots for ships 65 feet and longer. Collisions with large vessels have been cited as one of the chief threats to the whales, whose population has dwindled to fewer than 500.

Right whales migrate seasonally from their breeding grounds off the coast of Florida, Georgia and South Carolina to plankton-rich ocean feeding grounds in New England and Canada.

There were a number of right whale sightings on the Vineyard this year, beginning in February when a large pod was spotted off South Beach in Edgartown. In July three right whales were seen in waters off Oak Bluffs.

The news from NOAA was hailed by protection groups. "This is a huge victory for these endangered whales," said The Humane Society of the United States in a release.