For the first time in centuries, a trio of nests containing viable wild Atlantic salmon eggs have been found in the Connecticut River system.

After disappearing from the watershed, with just a problem-plagued restoration program delivering minimal hope for decades, biologists are excited to see that maybe, just maybe, this once common and important fish species could be making a comeback on its own. Reports Field and Stream:

"Wild Atlantic salmon were once plentiful in the 407-mile-long river, and biologists estimate that before colonization up to 50,000 fish made annual runs upstream. But the species quickly died off after a series of dams blocked the fish's migration routes and as the river became increasingly polluted."

A 45-year, $25 million effort to restore wild Atlantic salmon to the Connecticut River watershed ended in 2012 due to the cost of the program and the low rate of success. The program would catch salmon on their way upstream, raise young salmon in hatcheries and release them into the river with the hope that this would provide the highest rate of survival for the fish.

A pair of salmon spawned in a tributary of the Connecticut River back in 1991, but according to The Hartford Courant, "officials believe those eggs were deposited by late-arriving salmon, in a non-traditional spawning area where the eggs had almost no chance of surviving."

Between the low rate of salmon returning to spawn and hurricane damage in 2011 to one of the main hatcheries, the costs were too high and the restoration program came to an end.

So when biologists spotted five wild salmon swimming upstream during spawning season in 2015, rather than catching them as they would have for the hatchery program, they tagged them and let them continue on their way. The result is three nests that might provide the first wild-born Atlantic salmon the river has known in over two centuries.

Unlike the nest discovered in 1991, these nests are in a location where salmon once commonly spawned and have a good chance of hatching. Biologists are waiting until spring to see if the eggs successfully hatch, and if they do, it may mark the first time wild salmon have successfully spawned since the Revolutionary War.

According to Hartford Courant, "Bill Hyatt, DEEP's bureau chief for natural resources, said he doesn't believe the new salmon nests indicate that ending the federal program was premature." There were other factors beyond the program's control that also affected success, including "Salmon and other fish populations in the North Atlantic saw massive population declines in the 1990s as their food supply disappeared. Shifting ocean currents in the 2000s further damaged the recovery," reports Good News Network.

This nest of wild Atlantic salmon eggs is one of three discovered by biologists. This nest of wild Atlantic salmon eggs is one of three discovered by biologists. (Photo: Connecticut Fish and Wildlife)

And it isn't just locals who are excited about the prospect of wild Atlantic salmon spawning on their own. Writes Al Jazeera of the image above:

"A tight-cropped photo of one of the nests posted in December to a state Facebook page triggered a storm of its own. The photo went viral and became the most shared piece of news in the history of the wildlife department, Gephard said. [Stephen Gephard is the senior fisheries biologist for the state of Connecticut.] Email listserves for scientists and message boards for fishermen lit up, said Kocik, who works in Maine. Soon Gephard was fielding questions about the salmon from local, regional and national media. The attention suggests there might yet be another effort to restore wild Atlantic salmon to the Connecticut River, despite the odds."

After so much effort and now a glimmer of success, the biologists are keeping the location of the nests secret in the hopes that they will be left undisturbed through the winter so they can have the best odds of hatching. Those rooting for the recovery of Atlantic salmon in their old spawning grounds are eagerly awaiting good news later this spring.

Jaymi Heimbuch ( @jaymiheimbuch ) focuses on wildlife conservation and animal news from her home base in San Francisco.