A group of workers that included staff from the Dept. of Marine Resources, Gulf of Maine Council on the Marine Environment Habitat Coordinator Slade Moore and volunteers from the Damariscotta Mills Fish Ladder Restoration waded into the ladder’s pools, Nov. 26, to unplug drains, capture several species of fish and get them to their winter homes.
Maine Dept. of Marine Resources Marine Scientist Claire Enterline said the fishway is dewatered every year at this time. Then in early spring, the flow is turned back on to attract alewives to their spawning grounds.
All through the summer, the ladder is open and water flows through. After the juvenile alewives make their annual autumn trek to saltwater, the water is turned off in the ladder and redirected to the natural falls alongside the ladder and the powerhouse below.
Freshwater species, such as brown trout, were captured and carried upstream to the pond, while saltwater dwellers were brought to the tidal area at the bottom of the fishway.
Enterline said adult eels live in freshwater and feed on many small fish including juvenile alewives, but juvenile eels need to migrate to saltwater.
“Elvers – glass eels – ascend to freshwater in the spring and live there for many years, but return to saltwater when they’re ready to spawn,” she said. “They die right after they spawn.”
Alewives, which do not die after spawning, return to saltwater after their annual swim up the ladder to spawn. This cycle is repeated each year.
This fall, dewatering also provided time for new cement work built during this year’s restoration projects to cure.
“The towns work to make the ladder work,” Enterline said. She said DMR does what it can to support the project.
During the annual spring alewife run, DMR takes weekly counts to estimate the timing of the migration and the growth cycles of the fish. The dam operator and adjacent towns collaborate in this effort, Enterline said.
“Damariscotta Lake fish tend to be smaller than others,” she said. Enterline said the 2012 migration at the fish ladder lasted longer than in other years. “It seemed to be a successful year,” she said.
On Nov. 26, water level regulator Kurt Oehme turned off the flow through the ladder. Those assembled for the morning’s work waited as the pools drained and then went from pool to pool, collecting any remaining fish.
Enterline said the group gathered approximately 20 Brown Trout, four landlocked salmon and one Brook Trout. Along with a handful of adult eels and one sunfish, all of these were returned to the lake.
Approximately 50-75 juvenile alewives were taken to the tidal area below the fishway. Enterline said these would find their way to saltwater when they are ready. No juvenile eels were found.
“Freshwater species find the pools a great place to hang out and feed,” she said. “It’s really great habitat for them. The water stays cool. It’s oxygenated because it’s flowing between the pools. They have a food source in the form of alewives and elvers.”
She said it was probable that some glass eels remain in the pools. “They’re so small that it’s hard for us to see them,” Enterline said.
“They have an uncanny ability to survive and move with just a trickle of water,” she said. “If they’re in there, in cracks, because the water will never totally stop running through the fishway, most likely those eels will find their way up to the lake or even survive in the water left in the pools.”
