The speed restriction will continue to limit boats to 10 knots or fewer, and NOAA is encouraging boaters to be extra vigilant in shipping lanes because whales have been spotted in those areas.

The voluntary vessel speed restriction zone put in place by the National Oceanic and Atmospheric Administration has also been expanded to cover areas off the coast as far north as Gloucester and around the Cape, extending down just south of Block Island, NOAA officials said on Wednesday.

Vessel speed restrictions put in place to protect migrating whales have been extended to late April, according to federal officials.

“With an unprecedented 20 right whale deaths documented in 2017 and 2018, NOAA is cautioning boaters to give these endangered whales plenty of room. We are also asking commercial fishermen to be vigilant when maneuvering to avoid accidental collisions with whales,” NOAA said.


Right whales are among the world’s most endangered species, with just over 400 alive.

A video of a right whale enjoying warm waters off the Cape excited many viewers earlier this week. A NOAA spokeswoman said 160 whales had been spotted in Cape Cod Bay on Sunday.

An area stretching from Race Point in Provincetown to Block Island off Rhode Island is restricted until April 30 and Cape Cod Bay is restricted until May 15.

NOAA also encourages boaters to use the Whale Alert App as a way to stay updated on recent whale sightings.

A statement last week from NOAA said the average number of whales dying or being seriously injured by entanglements between 2012 and 2016 averaged 5.15 whales per year, prompting this extension.

“These numbers include only documented mortalities and serious injuries. Actual mortalities and serious injuries of right whales in U.S. fisheries are likely higher,” the statement said.


For right whales to recover (pop. now ~411), fishing-related serious injuries and mortalities in U.S. waters need to be reduced by 60-80%. (4.3 to 0.9 per year) Working together to find best ideas for lobster industry and right whales. @NOAAFish_NEFSC https://t.co/pGkKfqy3oG pic.twitter.com/S9Z3VtgYPF — NOAA Fisheries NE/MA (@NOAAFish_GARFO) April 6, 2019

Sabrina Schnur can be reached at sabrina.schnur@globe.com. Follow her on Twitter @sabrina_schnur.