Shoreline Change Mapping
Estuaries are areas where rivers meet the ocean. These transitional areas dominate the landscape of Barnegat and Delaware Bay and are highly important to New Jersey’s coast. The estuaries of Barnegat and Delaware Bay are dense with vegetation, fish and wildlife of all kinds and support the State’s recreational and commercial fisheries. Estuaries also help provide clean water by trapping pollutants and debris that get washed down from rivers. Their scenic beauty and the opportunities for outdoor recreation which they afford attract visitors from all over.
Estuarine shorelines, where land meets the water, are highly dynamic and are governed by the flow of the tide. The constant action of water and winds as well as the occasional storm and, on longer time scales, sea level rise, are at work, reshaping the shoreline. While these changes in the shoreline are natural, human development is altering the shoreline and slowing the natural rhythms of shoreline movement. The hardening of shorelines, such as bulkheads, is withholding sediment from entering the water and moving to nearby marshes. Bulkheads are installed to “hold the line” and protect water-front property from erosion. They also allow immediate access to deep-water, making them convenient for boaters. Bulkheads take the place of shallow intertidal habitat that would normally occupy the shore. In addition to habitat loss, the conversion from shallow soft-bottom intertidal areas to deep-water hard vertical structures can facilitate erosion on adjacent shores. When waves encounter natural shorelines, the energy dissipates as the wave drags over the bottom and encounters shallow water (like a wave breaking on a beach). When a wave encounters a hardened shoreline in deep-water the wave energy is not absorbed but redirected, hitting natural shorelines with full force, causing shoreline erosion.
This loss of shoreline can have significant consequences, not just for fish and wildlife, but people as well. Estuaries help buffer the energy from strong storms, such as Hurricane Sandy, and help defend properties from flooding. As the water is pushed through the dense vegetation of a marsh the energy is dissipated and flood waters recede. If shorelines continue to erode coastal communities will lose the protection from coastal hazards which estuaries provide.
NJDEP is using a suit of tools to determine where and by how much shorelines are changing. This knowledge will aid homeowners, local government, engineers, scientists, managers and planners in deciding where shoreline hardening should be avoided, where vital habitats and property is threatened and where marshes should be restored using nature-based techniques.
View Shoreline Change Maps