In this March 28, 2018, file photo, a North Atlantic right whale surfaces in Cape Cod bay off the coast of Plymouth, Massachusetts. A judge ruled on April 9, 2020, that the federal government had failed to adequately protect endangered whales from lobster fishing activities. Credit: Michael Dwyer / AP

BOSTON — The federal government is extending three protective zones off the East Coast that are designed to prevent collisions between ships and whales.

The zones are intended to protect North Atlantic right whales, which number only about 360. The National Oceanic and Atmospheric Administration said Monday the protective zones are located south of Nantucket, Massachusetts, east of Boston and southeast of Atlantic City, New Jersey.

Mariners are asked to avoid the areas altogether or transit through them at 10 knots or less. The three zones were established in late February. The Nantucket zone has been extended to March 13 and the Boston and Atlantic City zones have been extended to March 14.

The whales are vulnerable to ship strikes and entanglement in fishing gear.