Excerpt:
More than 30,000 small dams currently block river tributaries from Maine to Maryland. New initiatives to remove them are aimed at restoring natural flows, improving habitat for aquatic life, and reopening thousands of river miles to migratory fish, from shad to American eels.

The glass eels, 3 inches long with skin so translucent it reveals the beating of their tiny hearts, writhe with unexpected strength in the palm of a hand. For a year they have ridden the tides from their hatching site, in the Sargasso Sea, to the mouth of upstate New York’s Saw Kill Creek, a narrow tributary of the Hudson River. That’s where a fyke net set out by biologists, counting migratory American eels as they seek clear and flowing creeks in which to mature, captures them.

Although not considered endangered by the U.S. Fish and Wildlife Service, American eels have for decades been tallied at historically low numbers throughout the Northeastern United States, the most heavily dammed region in the nation. Fishing regulators consider their stocks depleted. But they’re not the only species in trouble here. Alewife and blueback herring, shad, shortnose and Atlantic sturgeon, and Atlantic salmon are all on the decline in Northeastern river systems. In response, a range of government agencies, private landowners, and environmental groups have been collaborating to restore these populations — by removing the dams that block their passage.

Although dam removals have been happening since 1912, the vast majority have occurred since the mid-2010s, and they have picked up steam since the 2021 Bipartisan Infrastructure Law, which provided funding for such projects. To date, 806 Northeastern dams have come down, with hundreds more in the pipeline. Across the country, 2023 was a watershed year, with a total of 80 dam removals. Says Andrew Fisk, Northeast regional director of the nonprofit American Rivers, “The increasing intensity and frequency of storm events, and the dramatically reduced sizes of our migratory fish populations, are accelerating our efforts…”