Spring is alewife season in Maine. No, it isn’t when we go hunting for the wives of ale-drinkers or -makers, it is when the alewives, a sea-going fish in the herring family, using their sense of smell, return to the freshwater lakes and ponds where they were spawned to themselves spawn. Alewives (Alosa pseudoharengus), are fairly small fish of less than a foot in length, whose number used to be so great that bears would wade into streams to eat their fill as the millions of fish made their way upstream. They have long been smoked and preserved for winter use, or harvested for lobster bait in Maine, but the damming of Maine’s rivers and streams for energy interrupted their passage and the number of alewives has plummeted in recent years.
Maine is working to restore the populations of alewives and other sea-running fish by dam removal and the construction of fish ladders and passageways. Even in the 12 years I’ve lived next to the Kennebec River, several dams have been removed, hastening the return of salmon and even sturgeon to the river. Community groups, municipalities and state and federal agencies are working together to restore fish passageways and fish ladders across the state to keep the alewife and other sea-run fish from extinction.
Sunday we took Dan’s mom to the historic Damariscotta Mills Fish Ladder to see the alewives. The ladder allows the fish to pass from Great Salt Bay into the ladder, marked with a yellow arrow in the photo, and then upstream along the yellow line into Damariscotta Lake at the second arrow.
A coalition of local community groups has been working hard to restore the ladder and educate the public about the alewives and the role they play in the ecosystem. It is an amazing, inspiring sight. Thousands of fish fill the stream, swimming as one body, packed so closely together it is difficult to see them as individuals when you first look. The new fish ladder is engineered to add oxygen the water and has 8 resting pools where the plucky fish can catch their breath, so to speak, before continuing. Netting over the pools prevents eagles, osprey, seagulls and other birds from excessive snacking as the fish make their way up the ladder. The fish ladder is abutted by homes on one side. In the photo above you can see some of the resting pools looking down the ladder. At the top of the fish ladder is a concrete dam. The alewives fight their way through a small opening in the dam into Damariscotta Lake. After all their struggles to return to the lake, they are met with hungry ducks and cormorants (as seen in the photo) eager to dine. The alewives form large schools, and eventually move to quiet water to spawn. After spawning, the fish return to the sea, traveling downstream tail first, much like they traveled upstream. A female alewife might lay 60,000 to 100,000 eggs, but only a tiny fraction survive to adulthood. It is truly an amazing journey.
(above aerial photo from the Damariscotta Mills Fish Ladder Restoration webpage, my graphics added)