(CNN)Scientists are monitoring the health of a group of critically endangered orcas in the Pacific Ocean following news that Scarlet, an emaciated member of the pod, is presumed dead.
Teams check health of endangered pod as sick orca is presumed dead
"We did an extensive search on Thursday and Friday, both by air and on water but didn't turn up Scarlet or her body," spokesperson Ruth Howell of National Oceanic and Atmospheric Administration (NOAA) Fisheries said Monday. "We called off the search Friday afternoon."
The most recent photos of Scarlet, also known as J50, showed the underweight 3-year-old orca was in bad shape. She has not been seen since September 7.
"Aerial photos from August and September showed her condition had gotten worse," Howell said. "She was extremely emaciated, and her condition was worsening."
Scarlet was among a group of endangered, rapidly dwindling Southern Resident killer whales that frequent the Pacific Northwest. Teams working off Washington state and Vancouver, Canada, had been trying to get her food and antibiotics.
The nonprofit SR3 has partnered with NOAA Fisheries and currently has a team in the field attempting to get more information about the health and wellness of the pod, Howell said.
"Working under a research permit from NOAA Fisheries, we have been able to fly a custom-made research drone high above the whales, to non-invasively collect images to measure the width (to infer fatness) and length (to monitor growth) of the whales," said the SR3 website.
A task force set up by Washington Gov. Jay Inslee on September 24 will release a draft of recommendations to help the orcas.
"Losing Scarlet is particularly difficult after a truly heroic effort on the part of so many in the US and Canada to save her life," said a statement from the task force. "And her suffering and death follow too closely the death of J35's calf and the 17 days of orca grieving that brought world attention to the critically endangered southern resident orcas."
Scarlet is part of the Southern Resident population that includes Tahlequah, whose heartbreak made headlines worldwide after she carried her dead calf for days this month.
Tahlequah's calf died a few hours after its birth last month. Not wanting to let its body sink to the ocean floor, she nudged it toward the surface as she made her way through the Pacific, off the coast of Canada and the northwestern US.
One of the problems affecting whales is the lack of salmon, their main source of food due to overfishing for commercial consumption. And man-made contraptions, like hydroelectric power sources, block their path to release eggs.
Orca whales also do not have babies often or in large numbers, and when they do, it is a long process. It takes a calf a little under a year and a half to fully develop in the womb, and they nurse for another year.
The Southern Resident population has reduced to 75 animals, and has not had a successful birth in three years. In the past 20 years, only 25% of the babies have survived.
"Extinction is looming," Center for Whale Research founder Ken Balcomb told CNN.