Scientists made a surprise discovery of a North Atlantic right whale calf in Canadian waters. They say the discovery is cause for celebration.
The discovery comes as the critically endangered species continues to face threats from entanglement in fishing gear and ship attacks. The aquarium estimates there are about 380 North Atlantic right whales left.
According to the New England Aquarium’s press release, researchers with the Mingan Island Cetacean Study photographed a mother and her calf near Anticosti Island, Quebec, on September 25.
The photos were sent to scientists at the aquarium’s Anderson Cabot Center for Ocean Life, which maintains the North Atlantic Right Whale Catalog, a database for identifying and tracking individual whales.
After weeks of comparing photos and examining sighting records, researchers determined the calf was new. The calf’s mother was identified as Silt, catalog number 1817, a whale at least 38 years old who has now given birth to six known calves.
No mud had been seen since February. It was not detected during boat and aerial surveys along the US East Coast in the spring and summer.
“This is an exciting discovery for us this late in the year,” Amy Warren, a scientist at the aquarium’s Anderson Cabot Center, said in the news release.
The new calf, estimated to weigh about 15,000 pounds (6,804 kilograms), was identified more than five months after the end of the annual calving season, which runs from mid-November to mid-April in the southeastern United States.
The researchers initially documented 23 mother-calf pairs. This surprising discovery off Quebec brought that total to 24.
A family marked by survival and loss
Silt had six known calves, three grandchildren and one great-grandchild born in 2026.
The aquarium reported that Silt survived at least five fishing tackle entanglements, some of which left significant scarring on his head and tail. Two of their descendants died after these encounters.
Division, born in 2022, died this year after a serious entanglement. Her oldest known calf died in 2005 after being hit by a ship. This family history highlights the dangers this species faces in the North Atlantic. Researchers hope Silt’s newest calf won’t face the same threats.
On a hopeful note
Phys.org described 2025-2026 as the most productive calving season since 2009. The recently discovered calf was welcomed as hopeful news as the species population remains small.
There are only about 70 females of childbearing age left. The species lost around 25 percent of its population between 2010 and 2020. No calves were born in 2018. The population has recovered somewhat since 2020, but right whales still face threats.
The New England Aquarium maintains the catalog of North Atlantic right whales in collaboration with researchers and organizations along the east coast of North America and eastern Canada.
According to the press release, the catalog documents births, injuries, migration patterns and age. Scientists reconstruct the history of individual whales. However, Silt’s latest calf shows that even extensive research can miss individual animals.
“It just shows you how big the ocean is and how these animals can get lost out there,” Sears said physics. The latest sighting adds another calf to one of the busiest breeding seasons for North Atlantic right whales. It’s a promising development for the species.
