Finally there is some good news for the North Atlantic right whale — about 6,000 pounds of good news.

On Dec. 28, scientists with the Florida Fish and Wildlife Conservation Commission conducting flyovers off the coast of northern Florida confirmed the first right whale calf in nearly 22 months. One week later, they spotted a second. And now, with the birthing season in full swing, scientists last Thursday spotted a third calf swimming with its mother off of Florida’s Amelia Island.

“Word from my colleagues down in the Southeast is that there’s been three, which is a lot more than zero, but nowhere close to where they need to be,” said Charles (Stormy) Mayo, senior scientist at the Center for Coastal Studies in Provincetown. “So let’s hope they pop a bunch more.”

For the first time since scientists started tabulating numbers, survey teams spotted no right whale calves during the winter of 2017/2018. The absence of calves, coupled with an unusual mortality event in which 17 of the massive aquatic mammals were reported dead, have scientists fearing that the critically endangered species could be the first of the great whales to reach extinction because of anthropogenic — or human — causes. The 2017 North Atlantic Right Whale Consortium report card estimates that there are only 400 to 500 whales left.

But the recent good news from the Florida-Georgia coastline comes with equally exciting news off the southern shore of Nantucket, where an aggregation of 100 right whales was spotted on Jan. 15. Even with the partial government shutdown, NOAA Fisheries was able to get an exemption to continue right whale aerial surveys as planned through Jan. 15.

Although most employees from the National Oceanic and Atmospheric Administration (NOAA) cannot work because of the shutdown, the organization has instituted a voluntary vessel speed restriction zone through Jan. 30.

The restriction asks boaters to keep their speed to 10 knots when sailing through the dynamic management area, which stretches approximately 1,600 square nautical miles from 41 degrees, 12 minutes north to 40 degrees, 28 minutes north, and longitudinally from 70 degrees, 36 minutes west to 69 degrees, 31 minutes west.

First calf in nearly 22 months was born on Dec. 28. Two more followed. — FWC Fish and Wildlife Research Institute

Julie Roberts, an exempted spokesman for NOAA, said long-term research on right whales cannot be conducted during the lapse, although NOAA has attempted to provide essential operational support for right whales through the establishment of dynamic management areas.

Mr. Mayo said it’s surprising to see so many whales congregating near the waters of the Vineyard. He said such large aggregations aren’t normally seen in Massachusetts waters outside of Cape Cod Bay.

“One hundred is a huge number,” he said. “That’s an area that to my knowledge wasn’t known to be a high use area.”

Mr. Mayo and his colleagues fly what he calls “strip searches” over the region, hovering at low altitudes to count right whales. A similar process occurs about 1,000 miles south, where the Florida Wildlife Commission’s (FWC) right whale team conducts surveys calf from Dec. 1 through March 30, even though the season can extend from November through April. “The whales trickle down here in the winter,” said Katie Jackson, a senior right whale researcher with the FWC. “They come here pregnant, they give birth here in the southeast, and then we expect them to be resident while calves gain weight and coordination. And then they migrate north toward the feeding areas.” Ms. Jackson said that the three calves spotted this year are all healthy and likely to migrate north with their mothers soon.

“They are all on the younger side so they are working on putting weight,” Ms. Jackson said. “But they look good.”

The three mothers, numbered 2791, 3317 and 1204, are all previously known breeding females, according to Ms. Jackson. Female right whales generally begin calving between ages eight and eleven, and then take about three years to recover after their first calf. But 2791, a 22-year-old female, had her first calf since 2009, and 1204, the most recent mother, had her first since 2013.

“That’s a pretty big gap, which is worrisome,” Ms. Jackson said. “But 3317, who’s known to be 16 years old, had her last calf in 2016. So she started young and that was only three years ago.”

According to Ms. Jackson, the calf spotted on Jan. 17 was her mother’s ninth, which has tied a record with two other whales for the most calves from one female. Although the prolific breeder is known to be at least 37, right whales can live to 100 and breed throughout their lifespans once they reach sexual maturity. Ms. Jackson said the issue is that female right whales just aren’t living long enough.

“The bigger problem is that right whales, and females in particular, are not surviving until old age,” she said.

Recent analysis work done by NOAA Fisheries shows that females are dying by about ages 50 to 60, with many dying before they reach the age of 30, according to Ms. Jackson. That only gives a short window for calving. And to make matters worse, those whales that are calving are doing so with larger rest intervals. A study released in November by NOAA right whale expert Peter Corkeron theorized those lengthier intervals could be the result of the energy expended from fishing net entanglements.

After spotting no calves in the winter of 2017/2018, scientists like Mr. Mayo were hoping for between 15 and 20 calves this season. With only three spotted so far, that number looks unlikely. Even so, the FWC will continue to conduct aerial surveys well into the spring. Ms. Jackson said the survey team has seen other female whales in the warm waters off the Florida coast, meaning that there’s always a chance for more calves.

“We have seen a couple of other potential mothers [known calving females],” Ms. Jackson said. “There’s no reason for them to be here other than to calf . . . so there’s hope that there could be more out there. We’ll hang onto that hope.”