BALTIMORE – Beginning today, ships that are at least 65 feet long will have to slow down in areas along the East Coast to reduce collisions with endangered North Atlantic right whales.

Under a new federal regulation, the ships must travel no faster than 10 knots in southeastern Atlantic and mid-Atlantic waters where the whales usually gather. The speed restriction will extend 20 nautical miles around major ports. Researchers with the National Oceanic and Atmospheric Administration say most right whale sightings occur within 20 nautical miles of shore.

Similar speed restrictions will take effect in waters off New England starting in January, as the whales begin to migrate north.

NOAA says only 300 to 400 North Atlantic right whales remain in existence. The whales migrate each year from the southern U.S. to the Gulf of Maine.