by Dr. Lenore Tedesco, Executive Director
The Wetlands Institute, along with our project partners at the US Army Corps of Engineers – Philadelphia District and the NJDEP Fish and Wildlife team, is pleased to report that the construction phase of the project at Scotch Bonnet Island was successfully completed this fall.
Our goal was to save Scotch Bonnet Island from drowning under the stress of repeated tidal flooding related to accelerating sea level rise, which is submerging tidal marshes. To raise the marsh elevation, we used clean sediment dredged from the NJ Intracoastal Waterway near Nummy Island to enhance areas that have fallen below the elevation range for healthy marsh.
By the completion of construction in December 2024, we had placed 14,000 cubic yards of sand and mud on the marsh, covering an area of 5.5 acres. Upon completion of the placement, the marsh elevation was between 4.2’ NAVD88 and 2’ NAVD88 and the material is greater than 3’ thick in many places. The elevation is slightly higher than we expect it to be when the site settles out more. We achieved all construction goals and are monitoring the site for evidence of performance.
By mid-May, early recolonization of the barren mud surfaces had begun with both Spartina marsh grass and pickleweed sprouting. An unexpected bonus has been site usage for spawning horseshoe crabs near the creek and an abundance of migratory shorebirds that are using the higher ground to rest and feed.
