In 2014, Maine began developing a fish elevator to carry American shad past Milford Dam. 12 years later, the system could reopen 600 miles of river habitat to a fish whose migration has been blocked for decades

A fish elevator may not sound like the kind of machine capable of changing an entire river. On Maine’s St. Croix River, though, a new fish lift at Woodland Dam is being designed to do something much bigger than move fish past concrete. It could help reconnect migratory fish with about 600 miles of habitat and 60,000 acres of spawning habitat used by alewives.

The project is part of a much larger restoration effort involving the Passamaquoddy Tribe, the Maine Department of Marine Resources, NOAA and other U.S. and Canadian partners. The goal is to restore a river system that once supported enormous runs of sea-run fish but was progressively divided by dams and other development. The return of those fish could also send more food into the wider ecosystem, from river predators to marine species.

What is happening at Woodland Dam?

NOAA has awarded another $7.5 million to the Maine Department of Marine Resources to continue construction of fish-passage structures at Woodland Dam. The project includes a large modern fish lift as well as a second pool-and-chute fishway because researchers found fish concentrating at more than one location below the dam.


That matters because the old fishways at Woodland and Grand Falls were built decades ago and no longer match the scale of the restoration effort. NOAA says the broader project is intended to improve passage for several migratory species, including alewives, American shad and American eels.

American eels present a separate engineering problem. Young eels are remarkably good climbers, so new eelways will use surfaces that allow them to move upstream. Researchers are also using radio telemetry to understand how adult eels and juvenile alewives move downstream toward the ocean, information that can help make passage safer in both directions.

Why does one small fish matter so much?

Alewives are small, silvery river herring, but their ecological importance is much larger than their size suggests. They migrate between the ocean and freshwater systems, bringing a large pulse of living biomass into rivers during their spawning runs. Fish and wildlife ranging from ospreys and mink to larger marine predators can feed on them.

The St. Croix restoration could eventually support an extraordinary number of returning alewives. A restoration plan developed by the Passamaquoddy Tribe estimates that the river could potentially support more than 80 million adult spawning alewives if passage is restored across the major barriers. That would represent a dramatic increase from the roughly 900 fish recorded in 2002. The run has already recovered to more than 600,000 fish after restrictions on passage were repealed in 2013.

The geography explains why Woodland Dam is so important. NOAA reports that about 99% of the St. Croix’s alewife habitat is upstream of its three major dams. A barrier near the lower part of the river therefore does not simply affect fish at one location; it can determine whether they reach most of the habitat available to them.

Where do the whales come in?

Whales are part of the ecological picture, but the claim needs some context. NOAA expects that restoring alewives, American shad and American eels will increase available prey for whales, dolphins, groundfish and saltwater sportfish. In other words, the connection is through the food web.

That does not mean researchers have shown that whales are already following the St. Croix fish passage or returning because of the unfinished Woodland project. The restoration work is expected to increase prey availability as fish populations recover. Any larger effect on whales would depend on how the ecosystem responds after the fish runs become substantially larger.

The river has already shown what restoration can do

The Woodland project follows one of the most visible changes on the St. Croix. The Milltown Dam, which stood for more than 140 years, was dismantled after removal work began in 2023. Following the dam’s removal, hundreds of thousands of alewives moved upstream during their spring migration.

For the Passamaquoddy Tribe, the restoration is also about more than wildlife. The St. Croix, or Skutik River, has deep cultural and historical importance, and sea-run fish supported communities for generations. NOAA describes the restoration effort as the result of long-term tribal advocacy combined with state, federal and Canadian cooperation.

The remaining challenge is scale. Woodland and Grand Falls are still major barriers, and additional work will be needed farther upstream if the river is to become fully accessible to migratory fish. The immediate goal is not to create a spectacle for whales. It is much simpler: let fish reach habitat they have been unable to reach for generations, then see what follows.