U.S. officials from NOAA say that the ailing orca experts have been working to rescue is still struggling.
The agency says a team followed three-year-old J50 on Saturday for several hours and saw her fall one-kilometre behind her pod in a strong current.
Experts are also concerned as they did not see her eat in prime foraging areas off San Juan Island.
A charter company did report that they saw the orca catch a fish earlier Saturday, and NOAA is working to find out more.
Researchers from the University of Washington also tried to collect fecal samples during the observation.
Since Aug. 2 experts have been working to examine and help J50, after they noticed she appeared emaciated.
After multiple sightings and observations, an international team on Wednesday consisting of Canadian and U.S. crews obtained a breath sample to help assess any infection, and also administered antibiotics through a dart.
Although, on Friday, J50 was spotted in Canadian waters, and the agency said she appeared active and energetic.
READ MORE: Historic efforts underway to help ailing orca J50
Another orca in the pod, J35, made international headlines after carrying her deceased calf for 17 days straight and over 1,500-kilometres.
On the Saturday sighting, she was no longer seen carrying her calf and appeared to be in good condition.
READ MORE: Orca spotted without dead calf after 17 days
The endangered southern resident killer whales only have 75 members left, and J Pod has 27 whales.