After years of decline, wild Atlantic salmon could be back on the rise. Scientists say that salmon returns are up as much as 50 per cent over the last year.

"All I'm hearing is, Hooray the fish are back, the fish are back,'" Walter Regan of the Sackville River Association told CTV News.

Monitoring sites around the Maritimes are revealing some of the best returns in decades, almost doubling last year's levels.

"In terms of the numbers themselves, it's very significant," said Geoff Giffen of the Atlantic Salmon Federation.

Still the numbers don't reach the healthy populations of the 1980s, when tens of thousands of salmon flourished in the rivers. The numbers dropped to a few hundred in some areas.

"We have been down in the dumps for so long," said Regan. "We've been dealing with the black hole...babies going out to sea and adults not coming back."

Along with urbanization, pollution and predators, something else is killing the young salmon after they leave East Coast estuaries. Scientists at Dalhousie University are trying to solve the mystery.

"We have new information from the ocean," said Mike Stokesbury, lead researcher of the Ocean Tracking Network.

A new ocean tagging and tracking system tells researchers where the salmon are and how many. Scientists hope this will give them some insight into what is happening to the fish and the reason for the sudden upsurge.

"There's a switch in something that's happening to them. There's a higher survivorship," said Stokesbury.

Scientists say it's still too early to know whether the increase in Atlantic salmon will become a trend.

With a report from CTV Atlantic's Dennelle Balfour