NEW HOPE, Pa. — A dam removal project is having a positive impact on the Delaware River’s ecosystem, including a boost to the population of migratory fish.
Removal of the Columbia dam on the Paulins Kill in New Jersey has given migrating shad and sea lamprey access to 20 miles of spawning waterways that had been inaccessible for a century.
Shad are especially important for fishing in the Delaware where there are shad festivals and fishing contests
But Beth Styler Barry, director of river restoration for The Nature Conservancy in New Jersey, points out that people aren’t the only ones who will benefit from increasing the number of fish in the river
“More shad means more food for things like eagles, heron, bears, otter,” she states. “It brings an additional source of nutrition to the entire ecosystem.
Removing the dam also made it possible to restore 32 acres of floodplain that had been covered by the water behind the dam.
Kent Smith, chief of the steering committee for the Atlantic Coastal Fish Habitat Partnership, says the dam removal project on the Paulins Kill is a good example of restoring what environmentalists call white water-to-blue water connectivity.
“You allow for natural tidal cycles,” he explains. “Freshwater lenses can flow out over the surface of the estuaries and animals like American shad have the ability to move into their freshwater habitat to complete their life cycle.”
Shad started returning to the area less than three weeks after dam removal was completed last year and this year breeding sea lampreys also have been observed.
Barry points out that the restoration brings a number of environmental benefits including washing away built-up sediment and improved water quality.
“The Delaware as a whole is continuing to improve as an ecosystem and, especially as climate changes, the cooler water will be more and more important not only for spawning and feeding but for the temperature refuge,” she states.
Two more dams on the Paulins Kill will be removed over the next two years, giving migrating fish access to 45 miles of rivers for spawning and improved habitat for resident species.
Support for this reporting was provided by The Pew Charitable Trusts.