Brian Gisborne/Fisheries and Oceans Canada via AP On Aug. 7, 2018, a southern resident orca, known as J50, is shown swimming with her mother, J16, near the west coast of Vancouver, British Columbia.

An orca from an endangered pod living in the waters off the Pacific Northwest is presumed dead, the second female from the group to die this year, according to wildlife officials.

J50, a southern resident killer whale that had been sick for months, has not been seen by scientists since last Friday even though every other member of her family group has been observed several times in recent days. The 3-year-old whale has been struggling since 2017, continually losing weight to the point of having a difficult time swimming, according to The Seattle Times. Researchers had taken extreme measures to save her, including darting her with medicine and dropping live chinook salmon dosed with antibiotics in front of her in hope she would eat them, but the efforts didn’t work.

“Watching J50 during the past three months is what extinction looks like when survival is threatened for all by food deprivation and lack of reproduction,” the Center for Whale Research, which has been actively monitoring the pod’s health, said in a statement on Thursday. “Not only are the Southern Resident killer whales dying and unable to reproduce sufficiently, but also their scarce presence in the Salish Sea is an indication that adequate food is no longer available for them here, or along the coast.”

NOAA has not yet given up hope that the whale may still be alive, and has been working with various groups to track a superpod gathering of more than 70 whales near Washington state’s San Juan Islands.

“It is really important that if she is there that we find her,” Michael Milstein, a spokesman for NOAA, told the Times. “We certainly have not determined at this point that we are giving up.”

David Ellifrit/Center for Whale Research via AP J35, also known as Tahlequah, pushed her dead calf around the Pacific Northwest for more than two weeks in what was widely seen as a mourning ritual.

Another orca from the pod, known as J35, drew worldwide attention in August after carrying her dead calf for 17 days around the waters of the Pacific Northwest. The whale, also known as Tahlequah, swam with the carcass for more than 1,000 miles in what was widely seen as a mourning ritual. Her calf was the first to be born alive since 2015, but only survived for about 30 minutes.

With J50′s presumed death, there are now just 74 southern resident orcas left in the wild.

The Center for Whale Research noted Thursday that the pod of whales had been struggling in recent years due to a lack of chinook salmon, their primary food source.

“The message brought by J50, and by J35 and her dead calf a few weeks ago, is that the [the whales] are running out of reproductive capacity and extinction of this population is looming,” the group wrote.

Environmental groups also lamented the loss, urging drastic action to protect the beleaguered animals. Washington Gov. Jay Inslee (D) convened a task force earlier this year to address the animals’ dwindling numbers.

“It is a heartbreaking reminder that we cannot save these whales on a case-by-case individual basis,” Robb Krehbiel, the Northwest representative for the environmental group Defenders of Wildlife, said in a statement. “What J50 needed, and what her family continues to need, is healthy and abundant chinook salmon, which these orcas depend upon for survival. If we are unable to restore the salmon that these orcas need, more whales will starve to death.”