Although coastal salt marshes are now protected, man-made structures such as roads, bridges, undersized culverts, and earthen dikes remain as barriers that reduce tidal exchange and degrade habitat. Structures that reduce saltwater flows lead to long-term salt marsh habitat degradation through promotion of brackish invasive plants, poor water quality, and creation of physical barriers that limit access to nursery, refuge, and forage resources for fish.
Fortunately, many degraded coastal marsh habitats can recover lost functions if the appropriate hydrologic regime is restored. However, simply removing these impediments with no science-based understanding of the potential results of these actions can lead to unintended consequences to the salt marsh ecosystem. Geosyntec, in partnership with the Wells National Estuary Research Reserve, Brown University, Wayne Huber of Oregon State University and the Massachusetts Office of Coastal Zone management (CZM), received a research grant from the University of New Hampshire/NOAA Cooperative Program. The goal of the grant was to evaluate several different remote sensing and modeling technologies and integrate them into a comprehensive tool that allows coastal managers to predict the vegetative consequences in the salt marsh of the implementation of any given restoration technique.
Geosyntec's Scope of Services
Geosyntec combined analytical tools including remote sensing, water quality modeling, and Geographic Information Systems (GIS) to develop a tool that predicts the change in vegetation types in a coastal salt marsh should, for example, an undersized culvert be removed. This unique combination of analytical approaches provides a method and approach to predict changes when active measures are taken to remove coastal tidal restrictions and increase flushing of salt water into and out of coastal wetlands.
Local, state, and federal coastal restoration managers and private consultants now have a reliable tool to help them select appropriate sites for restoration efforts, and to predict the ability and extent to which the salt marsh will respond to those efforts. With a restoration of the salt marsh flow regime and vegetation, along will come all of the other aesthetic, recreational, and natural benefits of the salt marsh. These benefits may include, for example, the replacement of invasive Phragmites reeds with native Spartina grasses, increased water quality, and a restored nursery habitat for many types of fish. More information about the project and the SMART Tool can be obtained at http://ciceet.unh.edu/.