Following the removal two years ago of an obsolete dam in Manville, New Jersey, American shad are successfully spawning in the lower section of the Millstone River. The New Jersey Department of Environmental Protection (DEP) recently observed juvenile fish there for the first time since 1845. American shad (Alosa sapidissima) are the largest member of the herring family and are anadromous, as they spend most of their lives in saltwater, but return to freshwater rivers each spring to spawn. They played an important role in American history and economics.
New Jersey Department of Environmental Protection Commissioner Catherine McCabe says, “This species has an inherent tendency to recolonize once obstacles are removed from its migratory path.” During the Industrial Revolution, rivers were dammed for electric power and lakes, but during the last decade, dam removal has become a new call to action. Besides preventing fish migrations, dams also harm water quality in rivers by blocking water flow, trapping sediment and changing habitats.