In this July 14, 2021, file photo, Richard Dill, a compliance specialist and fishery biologist, leads a tour of Brookfield Renewable's Milford dam and fish lift. Credit: Linda Coan O'Kresik / BDN

In 2014, a new fishway began helping endangered Atlantic salmon make their way past the Milford Dam on the Penobscot River so they could spawn upstream.

Four groups now say the fishway is failing to be effective and the reason is timing. The groups include the Penobscot Indian Nation, the Natural Resources Council of Maine, the Atlantic Salmon Federation and the Conservation Law Foundation.

Daniel McCaw, the fisheries program manager for the Penobscot Nation, said when the fishway was first licensed, it was supposed to allow 96 percent of salmon to get past the hydropower dam. McCaw said that standard was met, but the fish also had to find the fishway in just 48 hours.

“They’re coming from the ice cold ocean and they need to get upstream into the cold water habitats as quickly as possible during the high flows of the late spring, early summer,” McCaw said.

But a Maine Department of Marine Resources analysis indicates 79 percent of salmon failed to meet the 48-hour standard.

McCaw said extra time finding and pushing past the dam robs salmon of strength, especially because they don’t usually eat during their swim upriver. McCaw said that likely has an impact on their ability to spawn.

The groups said neither the dam owner, Brookfield Renewable Partners, nor the federal government has taken steps to improve the situation, which they said, amounts to a violation of the Endangered Species Act.

Sean Mahoney, the executive vice president of the Conservation Law Foundation, said legal action is under consideration. Brookfield did not immediately comment.

This article appears through a media partnership with Maine Public.