After four days of scouring Great Slave Lake, search and rescue teams said on Thursday they believe there is little chance four men missing since Sunday are still alive.
Crews searching the lake found debris from the fishers' vessel, located underwater near the lake's west coast earlier this week, but RCMP said on Thursday evening there had been no sightings of the missing men.
"At this time, it is believed that all viable search options have been exhausted," police said in a statement. "With information to date, the probability of survival is low."
Sgt Brandon Humbke, from the Hay River RCMP detachment, said: “Our hearts are with the families as we draw to the close of day four.
"We will continue to support them in this difficult time."
The missing men are Stacy Linington, a 59-year-old from Hay River, and three fishers from the area of Lesser Slave Lake, Alberta: 51-year-old Daniel Courtoreille, 50-year-old Michael Courtoreille, and Jason Fulton, 40.
They left Hay River's wharf to check their nets early on Sunday morning. The four have not been seen since, despite an intensive search and rescue operation.
Police said officers had been "in constant communication" with the affected families. Many family members have travelled to Hay River, where the local friendship centre has been helping with food and a place for families to gather.
The search has involved RCMP, the NWT branch of the Civil Air Search and Rescue Association, rescue crews from the Royal Canadian Air Force and Canadian Coast Guard, and the federal Department of Fisheries and Oceans.
Boats have crossed the lake in grid patterns searching for signs of the men, while spotters in a Twin Otter aircraft first sighted the fishers' submerged boat on Tuesday.
So far, no information has been released to suggest exactly what kind of incident may have befallen the men. Weather conditions on the lake were particularly windy earlier in the week, but there is no confirmation that this played any role.