Marine mammal researchers say North Atlantic right whales are extending their stay in Cape Cod Bay and waters off southeast New England, where they have gathered this spring in large numbers.
NOAA Fisheries released updated data Friday that show 89 right whales were spotted in Cape Cod Bay on March 21 by scientists with the Center for Coastal Studies and 57 were spotted south and west of the Nantucket Shoals on March 30 by airborne scientists from the agency's Northeast Fisheries Science Center
The spring sightings come during the annual feeding migration of the North Atlantic right whales that takes them through the waters of New England, particularly off the coast of Massachusetts.
Heading into this migratory campaign, marine researchers estimated that about 366 of the endangered North Atlantic right whales still exist.
As an enhanced protection, Massachusetts has closed virtually all of its state waters to lobstering until at least May 1 and possibly until May 15 — depending on the presence or absence of the imperiled whales — to mitigate the possibility of gear entanglement.
The Fisheries Science Center jointly monitors the waters off New England with the Center for Coastal Studies and the New England Aquarium. They track the whales using aerial survey flights and passive acoustic detectors.
The updated data shows there have been 730 "sighting events" and 183 acoustic detections of right whales between Jan. 1 and April 4.
Some of those sightings and detections included more than one whale and some were re-sightings of whales already spotted.
"Surveys in Cape Cod Bay are finding large numbers of right whales as spring arrives in the bay along with the food the whales need," NOAA Fisheries stated. "On March 16, 78 right whales were sighted by the Center for Coastal Studies aerial survey team. On March 21, the 89 whales sighted included three pairs of mothers and calves."
This year, researchers have observed 17 live calves in the waters off Georgia and northern Florida, where some right whale females travel to give birth. Some of those mothers and calves already have appeared in the waters off New England.
"To date, survey teams in the region have sighted at least nine of these mother and calf pairs this spring in the Northeast," said Tim Cole a marine mammal researcher in charge of the whale survey team at the Northeast Fisheries Science Center.
Researchers perform the aerial surveys several times a week in areas visited by the whales in the past.
The Northeast Fisheries Science Center will fly its aerial survey flights on its Twin Otter aircraft until June 15, when the aircraft will be repurposed to another survey project through September. Other aerial and vessel-base surveys will continue.
Contact Sean Horgan at 978-675-2714, or email@example.com. Follow him on Twitter at @SeanGDT
The National Oceanic and Atmospheric Administration said it is asking mariners to route around the waters east of Boston or transit through the area at 10 knots or less until May 2 to avoid critically endangered North Atlantic right whales.
NOAA has deployed similar “slow zones” south of Martha's Vineyard and southeast of Chatham through April 24.
It is also reminding boaters and pilots of planes and drones that unless they have a federal research permit, it is illegal to approach with 500 yards of right whales, either from the water or the air.