For years I remember people commenting on how I should really go and see the fish ladder in Damariscotta during the annual alewife run. At the time, I wasn’t even sure what the difference was between elvers and alewives, and it was one of those things where you smile and nod but aren’t particularly interested. I was missing out.

I’ll start with a quick review of elvers for those who are like me and prone to confusing the terms. Elvers are baby American eels (sometimes referred to as glass eels) that float in from the Sargasso Sea where their parents spawn. They are part of a group of species called catadromous because they live in freshwater but spawn in saltwater. Oddly enough, the location of their spawning grounds and most of the details surrounding the event remain a matter of scientific speculation that has never been conclusively proven. No human has ever caught an adult American eel in the Sargasso Sea, but the larvae of their offspring have been traced back to this area. They are considered endangered by the International Union for the Conservation of Nature but not listed under the U.S. Endangered Species Act, a subject of some debate. But we’ve had a banner year for them here in Maine as the only state in the nation with a significant commercial harvest. The season ended early when the quota of just over 9,000 pounds was met in just a few weeks, but they can still be seen in large numbers in Camden Harbor as the wriggle their way around obstacles with astounding tenacity. They are the only fish that actually leave the water temporarily in order to climb — sometimes vertically — around dams and other barriers and they are a tremendous source of nutrients for entire ecosystems. Shine a flashlight into the harbor at night and you will have seen a glimpse of one of the world’s great migrations, still the subject of much scientific debate.

An alewife fights to get over Turner Falls on the Ducktrap River.


But back to the alewives, another migratory fish of tremendous importance here in Maine. Alewives are known as anadromous because they live their adult lives in saltwater but return to freshwater to spawn. Like salmon, they fight their way upstream against the current and when they get to a pinch point such as a natural falls or certain types of manmade fish ladders, it can be very exciting to watch them. Unlike salmon, who seek out streams and rivers with fast moving water and gravel substrate, alewives are in search of slow-moving water and lake- and pond-like habitat. They spend only a few weeks there, laying their eggs and returning to the ocean to continue their lives. But on the way they provide a veritable feast for everything from ospreys to eagles to largemouth bass. But even if you aren’t the least bit interested in the benefits they have for the ecosystem, it is worth the trip to see them swimming up one of the many Maine rivers they have access to. People travel from all around to the middle of nowhere just to see it and those who have will understand why.

The entrance to the Damariscotta Mills fish ladder.

Mid-May to mid-June is the best time to witness the migration and there a couple of good places I’d recommend, depending on what you’re in the mood for. Damariscotta Mills, in the Town of Nobleboro, on Route 215 is a good example of a pool and weir fish ladder and can be visited during daylight hours every day while the fish are migrating. It’s an easy trip that requires very little walking and is appropriate for all ages and physical abilities.

Another local option is the Ducktrap River at Turner Falls off the River Trail in Tanglewood. This is a longer hike but I’m glad that my friend Jackie convinced me to do it after she took her Montessori students on a tour of three local rivers. She was looking for examples of places with no fish passage at all (Megunticook), a fish ladder around a dam (Damariscotta Mills) and a free-flowing river with natural falls (Ducktrap). I now see why the students concluded that Ducktrap was the most exciting. Although the fish ladder in Damariscotta makes for an easier and more reliable climb for the fish, Turner Falls on the Ducktrap gives the fish a chance to really show off their ability to skim across bedrock and flop around falls in a show that is surprisingly interesting. Walk down quietly and you will likely get the chance to see bald eagles and osprey taking advantage of the pinch point in the river where they can catch the fish more easily. There are also many good places to witness the migration along the St. George River. For more ideas, visit for their alewife trail map.

Alewives schooling beneath Turner Falls on the Ducktrap River.

You may also get lucky and spot some alewives in Camden Harbor searching for a way into the river, but you have to know where to look. Stay in Camden to see the elvers but try a neighboring river for alewives.

Alison McKellar is a Camden resident and Select Board member. Her views are her own and do not reflect those of the Select Board or the editorial position of The Camden Herald. We welcome letters and guest columns reflecting other viewpoints via

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