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 has extended protections designed to help keep a declining species of whale safe off New England until Nov. 15.

The National Oceanic and Atmospheric Administration said it is asking mariners to go slowly through an area south of Nantucket or avoid it completely. NOAA started the protections after an Aug. 31 sighting of a group of North Atlantic right whales.

The whale numbers at only 366, the National Oceanic and Atmospheric Administration said last month in an estimate that reflects the population as of January 2019. The previous estimate, which reflected January 2018, was 412.

The whales are vulnerable to ship collisions and entanglement in fishing gear. The slow zone is located off of southern New England and east of Long Island, New York.