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 measures meant to protect an endangered species of whale off New England through the end of the month.

The National Oceanic and Atmospheric Administration said it is asking mariners to go slowly through an area south of Nantucket or avoid it completely. Similar protections have been in place throughout the fall.

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 southern New England and east of Long Island, New York.

Watch more: