Atlantic salmon returns to Penobscot River lowest in 5 years


Only 561 Atlantic salmon were counted in the Penobscot River last year, marking the lowest returns since 2016, when 503 fish made it to Milford and Orono.

The final numbers provided by the Maine Department of Marine Resources follow a massive influx of 1,439 Atlantic salmon a year earlier, which marked the highest return since 2011.

“Reasons for low ranges are likely low survival of fish at sea, impacts of drought while in the river, and impacts of impoundments and direct mortality in hydropower projects as fish migrate from rivers to the sea. “said Sean. Ledwin, DMR Sea Run Fisheries and Habitat Manager.

These are among the hurdles scientists continue to monitor as they attempt to restore a self-sustaining Atlantic salmon population to Maine’s rivers. And despite the 61% reduction in returns to the Penobscot River last year, experts are not alarmed.

“Although this year’s low returns continue a worryingly low abundance trend, they are not that far removed from the returns of the past 10 years, which have averaged 732 fish per year,” Ledwin said.

The 2021 total was the fourth lowest since 2000, but Ledwin previously explained that declining Atlantic salmon populations over the past two decades means returns to Maine’s rivers often vary widely from year to year. other.

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.

Atlantic salmon was once a prized catch for sport fishermen, who visited the Penobscot in large numbers.

Atlantic salmon in the Penobscot and Kennebec rivers are hampered by hydroelectric dams, which eliminate or reduce their ability to reach spawning grounds.

Ledwin said DMR staff reported returning salmon were in similar physical condition to those who returned in previous years.

“Salmon returns continue to be disappointing as we are still a long way from being able to downgrade the species and achieve self-sustaining returns that could support a fishery,” Ledwin said.

DMR biologists continue to work alongside Brookfield Renewable, which operates most of Maine’s hydroelectric dams, and other conservation groups such as the Atlantic Salmon Federation and Trout Unlimited looking for ways to make it more convenient for Atlantic salmon to travel to rivers, past dams and back to their traditional spawning grounds.

A major key is giving Atlantic salmon a way around hydroelectric dams and other man-made obstacles. Only 23 salmon were counted at Brookfield’s Lockwood Dam in 2021, while 21 were counted on the Narraguagus River in Cherryfield, according to the DMR trap count.

“We have much more control over the freshwater environment than when fish are at sea,” Ledwin said, “and so we prioritize improving fish passage upstream and downstream at dams. and increased numbers of fish in high quality productive habitats in Penobscot tributaries such as the Piscataquis and East Branch.


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