RIVIERE DU LOUP, Que. -- A washed-up baby beluga prompted a major rescue effort in Quebec last week, highlighting researchers' struggles to reverse the endangered population's decline.

The province's marine mammal emergency response team was called on Thursday after a vacationing family spotted the young beluga on the shoreline in Riviere-du-Loup, about 200 km northeast of Quebec City.

Veterinarians determined it was a newborn female who seemed healthy, according to Josiane Cabana of the Quebec Marine Mammal Emergency Response Network.

"She seemed to be in good shape and quite vigorous, and only a few hours old," she said.

Scientists have been sounding the alarm over the abnormally high number of carcasses belonging to pregnant or lactating females and young calves that have been washing up along the St. Lawrence river in recent years, but Cabana said it's relatively unusual to find one alive and in good condition.

The team made up of members from Quebec's Group for Research and Education on Marine Mammals (GREMM) decided the calf's best chance for survival was to put her in the water near a group of females in the hopes that one of them would adopt her.

The group had previously attempted a similar rescue once before, in 2008, although they never found out if it succeeded.

Cabana said members of the team administered first aid to the young female and kept her skin moist as she was transported to a boat.

She was put back in the water near a group of female belugas after about an hour of searching.

The young calf quickly blended in with the group, but left to swim with a different group soon after.

The team of researchers lost sight of her after that and Cabana said they don't know what happened afterwards.

She described the newborn's chances of survival as "low, to be honest -- but real."

She said females in captivity have been known to adopt orphaned calves, and some have even begun to lactate spontaneously.

The beluga population in the St. Lawrence estuary has been in a slow decline over the past decade, with many deaths seeming to come during calving season.

In 2015, four to six of the 14 carcasses found were newborns and three were females who died while giving birth, according to data compiled by GREMM.

Possible causes suggested by scientists include shrinking ice cover, boat traffic that could cause stress or interrupt communication between mothers and calves, and the decline of the herring population that provides an important food source.

Cabana says two of the four carcasses found on the shores of the St. Lawrence so far this year belong to lactating females.

She said that with less than 900 whales remaining in the St. Lawrence, each one is important -- including the little newborn whose fate remains unknown.

"It's one of the reasons this type of (rescue) effort will be made -- to give belugas a chance, to put all the chances on their side," she said.