American Shad Spawning Confirmed in Millstone River Following 2017 Dam Removal in Manville, Somerset County

The New Jersey Department of Environmental Protection has confirmed that American Shad are migrating and spawning in the Millstone River for the first time in 173 years, a year after removal of the waterway’s Weston Mill Dam in Manville, Commissioner Catherine R. McCabe announced on Monday, October 22.

Staff from the DEP’s Division of Fish and Wildlife, the U.S. Fish and Wildlife Service, and the Watershed Institute found evidence of successful American Shad spawning while cooperatively monitoring changes in fish assemblage following the summer 2017 removal of the Weston Mill Dam. Five juvenile shad averaging 4.3 inches in length were found 4.5 miles upstream of the dam at the base of Blackwell’s Mills Dam, which is considered the next upstream impediment to the movement of the shad. No shad have been found upstream of this location.

“This is great news and a wonderful environmental success story,” Commissioner McCabe said. “These juvenile shad were found in the first unimpeded migratory season after removal of the Weston Mill Dam, indicating this species has an inherent tendency to recolonize once obstacles are removed from its migratory path.”

A study to evaluate anadromous fish upstream of the Weston Mill Dam was initiated during fall 2016. The study provided baseline data a year prior to the removal of the dam, with subsequent monitoring to continue through spring 2020. Monitoring the fishery provides an important demonstration of the efficacy of dam removal to restore migratory fishes and to help determine which future dam removal projects will provide the greatest ecological benefits.

Read the complete news release here.