The Shawmut Dam on the Kennebec River. Michael G. Seamans/Morning Sentinel

The owner of hydroelectric dams in Maine said Monday it’s going to make changes to some of its operations to try to help save some of the last remaining wild Atlantic salmon in the United States.

The country’s last wild populations of the fish are found in a few Maine rivers. Salmon counters found fewer of the fish on one of those rivers, the Penobscot, last year than in any year since 2016.

Brookfield Renewable U.S. said Monday that it has begun shutdown procedures for dams on the lower Kennebec River to help the salmon migrate. The company is a subsidiary of a larger Canadian company that owns many dams in Maine.

A spokesperson for the company, David Heidrich, said the shutdowns will continue until the end of the salmon migrating season. The company said it made the voluntary move to shut down some operations after young salmon were found in the Sandy River, a tributary of the Kennebec.

The company is also working with regulators, including the Maine Department of Maine Resources, to help ensure safe passage of the salmon, Heidrich said.

“We are working closely with the DMR and the National Marine Fisheries Service to limit any potential impact to smolt during their downriver migration,” Heidrich said.

Atlantic salmon were once plentiful in American rivers, but factors such as dams, overfishing and pollution hurt populations, and they are now listed under the Endangered Species Act in the U.S. The fish is familiar to seafood consumers because it’s heavily fish farmed.

In recent years, Brookfield has been locked in a contentious battle with the state and conservation groups over the future of the Shawmut Dam and three other lower Kennebec River dams.

In September 2021, the Atlantic Salmon Federation and three New England conservation groups sued Brookfield in federal court alleging the firm has been killing Atlantic salmon at its dams on the Kennebec in violation of the Endangered Species Act. That suit is expected to go to trial this summer.

In November, the Federal Energy Regulatory Commission – the agency that oversees the relicensing of dams – announced they would conduct a comprehensive environmental review of the cumulative effects of four lower Kennebec River dams on salmon and other sea-run fish, a move that had long been sought by the conservation groups. FERC intends to issue a draft of its environmental impact study for the dams in August 2022 and a final version in February 2023.

Nick Bennett, staff scientist with the Natural Resources Council of Maine, wrote to the Federal Energy Regulatory Commission in April to say Brookfield should begin its protections at the beginning of the month, which young salmon start migrating.

“It’s too little, too late,” Bennett said Monday in an interview with The Associated Press.