It’s been two days since a U.S. group that tracks Pacific coast orca populations declared that J50, a critically-ill young killer whale, was dead.
Now, it appears U.S. government officials are inching closer to that conclusion as well.
On Saturday morning, the National Oceanic and Atmospheric Administration (NOAA) confirmed that it was ending its active search for J50, known to some as Scarlet.
“The team ended its active search last night, but the West Coast Marine Mammal Stranding Network remains on alert, and this is a time of year with many researchers on the water,” the agency posted to Twitter.
“The U.S. Coast Guard will also stay on watch, and will issue a notice to mariners to be on the lookout.”
WATCH: Research group declares missing orca J50 dead
Canadian officials haven’t given up yet.
The Department of Fisheries and Oceans said Saturday that it along with cetacean research organization Straitwatch were still involved in an active marine search.
J50, a three-and-a-half-year-old female, was last definitively seen on Sept. 7 near San Juan Island.
On Thursday, the Centre for Whale Research concluded that she had died, bringing the total remaining number of orcas in the endangered southern resident killer whale population down to 74.
J50 was born in 2015, part of an orca baby boom that turned out to be the last time that the southern residents produced any viable offspring.
WATCH: Coverage of sick orca J50 on Globalnews.ca
DFO scientists say she was underweight as a young animal, and her condition deteriorated to critical over the summer.
By late July, she was lethargic, severely emaciated and carrying parasitic worms.
Veterinarians and scientists from both Canada and the U.S. mounted a massive effort to diagnose her and treat her with anti-worming antibiotic shots.
If she is dead, scientists hope to find J50’s carcass in order to perform a necropsy and determine exactly what killed her.
Orcas as a species are not endangered, but the southern residents that live on the Pacific coast are listed as endangered under Canada’s Species at Risk Act.
Their population declined significantly in the 1960s and 1970s due to the live capture industry.
In more recent years, they have been threatened by a decline in stocks of their primary food source, spring salmon, along with marine pollution and marine noise which interferes with their ability to communicate and hunt.