Every year, those who are concerned about the plight of Atlantic salmon in Maine hold their collective breath as they wait to see how many return to the Penobscot River.
They can breathe a sigh of relief this year, because the preliminary numbers are solid.
An estimated 1,325 Atlantic salmon made their way through the fish lift at Brookfield Renewable’s dam in Milford and the dam in Orono, according to the Maine Department of Marine Resources, which oversees management and restoration efforts for Atlantic salmon in the state’s rivers.
Maine is home to the only native Atlantic salmon populations in the United States, where the fish have been protected under the federal Endangered Species Act since 2000. The fish were for many years a prized catch for sport anglers, who visited the Penobscot in large numbers.
The latest total is the second highest in the last 11 years and came on the heels of a disappointing 2021, when only 561 Atlantic salmon were counted. Last year’s total was the lowest since 2016.
Those returns followed a promising 2020 season during which 1,440 fish made it up the Penobscot River. That was the highest count since 2012.
This year’s estimate still leaves room for DMR to conduct its final audits to the count, which could include potential additions from redd — or spawning bed — count efforts.
“This is slightly higher than the average for the last 10 years but not out of the range of expected returns,” said DMR marine resource scientist Jason Valliere. “I expect favorable river flows, making the fishway potentially easier to find this year than it has in some past years, was one contributing factor.”
Numerous factors probably contributed to recent lower Atlantic salmon returns and the fluctuation from year to year, according to DMR. Those include likely low survival of fish at sea and the impact of drought during the salmon’s time in the river, along with impoundments the fish encounter and mortality at hydroelectric facilities.
Those are among the dynamics scientists continue to monitor as they try to help re-establish a self-sustaining Atlantic salmon population in Maine’s rivers.
Valliere said the fish he observed and handled this year seemed to be faring OK.
“Salmon appeared to be of normal size, health and demographic, although we are still early in the process digesting this data,” he said.
The count of river herring — alewives and blueback herring — also increased this year. DMR estimates that 2,052,837 of those fish made their way through the dams at Milford and Orono.
That’s an increase of approximately 300,000 over 2021 and is the most since the department started counting them in 2014.
“The river herring estimate was marginally up this year, not unexpected with ongoing restoration efforts,” Valliere said. “I expect again that favorable river flows during the passage season contributed to higher passage efficiency and effectiveness of the fishway this year.”