In this March 28, 2018 ,file photo, a North Atlantic right whale feeds on the surface of Cape Cod bay off the coast of Plymouth, Massachusetts. Credit: Michael Dwyer / AP

NANTUCKET, Massachusetts — The federal government is once again urging mariners to slow down off New England to help protect a rare species of whale.

The National Oceanic and Atmospheric Administration has extended a voluntary vessel speed restriction zone south of Nantucket. The agency implemented the zone in late August due to a sighting of a group of right whales. The use of the zone has been extended through Oct. 9.

NOAA is asking mariners to proceed through the area at 10 knots or less, or avoid it altogether. The right whales number only a few hundred and they are vulnerable to collisions with ships.