Scientists lose contact with rescued beluga whale, fear the worst

Scientists fear the worst but are holding out hope after losing contact with a young beluga whale that was rescued from a river in northern New Brunswick and released into the St. Lawrence Estuary inQuebec last month.

The Group for Research and Education on Marine Mammals (GREMM) team has been tracking the endangered whale through a satellite tag attached toits right flank. The teamstopped receiving transmissions on Tuesday, spokeswoman Marie-veMuller said in a statement.

"Hoping for a temporary problem, we waited two more days before having to accept the reality: we lost contact with the beluga," saidMuller.

• Beluga rescued from N.B. river swims towards possible reunion with pod: group

It's possible the satellite tag is broken,or has detached, the statement said.

But it could also meanthe young male beluga is dead and sank or is floating on its back, submerging the beacon and preventing it from transmitting.

Robert Michaud, the scientific director of GREMMwhoco-ordinatedthe complex rescueoperation after the belugagot trapped in the Nepisiguit River near Bathurst, N.B., hasn't given up hope.

"Our season with the belugas begins and we will keep our eyes wide open," he said in the statement.

If the young male beluga simply lost its beacon, it will have a scar under its dorsal crest that should make it easily recognizable, Michaudexplained.

Thwarted reserved prognosis

When the wayward whale was released on June 15, veterinarians were reserved about its chances of survival.They were particularly concerned about the low rate of electrolytes in its blood formula and doubted whether it would be possible to recover.

"However, the beluga had so far thwarted the prognosis by continuing its course, swimming more than 570 km through the estuary," the statement points out.

"Many developments can still occur, and the rescue operation has already tested hypotheses and advanced science."

Followed movements for 19 days

The satellite tag, which was programmed to send a signal when the whale breachedthe surface as many as 250 times a day allowed scientists to follow its movements as it made its way upstream.

Researchers think it's unlikely the Low Impact Minimally Percutaneous Electronic Transmitter (LIMPET) satellite tag is broken.

They say it'smore plausible it became detached, citing a 2015 research project that used the same type of tag and found retention did not exceed 13 days.

They used a different technique for the placement of the tag on the beluga, however, and managed to track itfor 19 days. The technique is used in Alaska on the beluga population of Cook Inlet and is supposed to providea follow-up of 60 to 130 days.

If the beluga is dead and washes up on shore, the satellite transmission could resume, allowing the scientists to locate the carcass and confirm its death.

Someone could also identify the carcass and report it to the Marine Mammal Emergency Call Centre at 1-877-7baleine, the statement said.

During the rescue operation, the beluga was coaxed into a net using an acoustic deterrent device, loaded into the back of a truck, and transported to a Bathurst airport.

The whale was then flown to Quebec in a small airplane, and after another car trip, was transferred to a boat to be set free close to a group of whales in the St. Lawrence Estuary near Cacouna, Que.