Location
States
New JerseyEcosystem
CoastalIntroduction
Edwin B. Forsythe National Wildlife Refuge (the refuge) spans over 48,000 acres of barrier islands, salt marsh salt marsh
Salt marshes are found in tidal areas near the coast, where freshwater mixes with saltwater.
Learn more about salt marsh , and freshwater wetlands. In southern New Jersey on the Atlantic Flyway migratory flight path, the refuge provides crucial feeding, nesting, and resting habitat for many coastal birds such as the saltmarsh sparrow (Ammodramus caudacutus) and American black duck (Anas rubripes). The salt marshes and barrier islands also act as buffers protecting neighboring communities from storm surges and flooding.
Beginning before the 1930s, large-scale ditching of saltmarshes occurred for mosquito management. These disturbances disrupted hydrology, altering the natural tidal flow and creating areas of poor drainage. Over time, sea level rise, erosion, and human activities further degraded the area, leading to widespread change of habitat and conversion of high marsh to low marsh and even open water. Marsh habitat is submerging, lowering elevation and resulting in the loss of crucial vegetative habitats such as saltmarsh hay (Spartina patens)-dominated tidal marshes that only exist along specific elevation gradients.
In 2012, Hurricane Sandy struck the Atlantic Coast, providing the refuge with the opportunity to utilize grant funds for recovery and coastal habitat resilience planning. The refuge implemented nature-based solutions to restore disconnected hydrology and increase marsh habitat. These solutions offer benefits for both human well-being and biodiversity. Refuge staff acted strategically by building elevation through sediment deposition and increasing native vegetation to sustain the marshland. In some areas, structures were removed to reconnect areas to natural tides. With the funds and help from the US Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), National Fish and Wildlife Foundation, and permitting assistance from the US Army Corp of Engineers (USACE) and the New Jersey Department of Environmental Protection (NJDEP), the refuge was able to restore flow, build and monitor marsh elevation, and protect important infrastructure in neighboring communities.
Key Issues Addressed
Ditch digging and impoundment creation have decreased hydrological connectivity and disrupted natural tidal flow. This disruption resulted in poorly drained marshlands and changed the marsh chemistry. These impacts have been exacerbated by sea level rise, storm surge, and edge erosion.
Significant vegetation loss and subsidence degraded the ecological integrity of the salt marsh at the refuge鈥檚 northern end. Wildlife is dependent on areas of both high and low elevation to sustain native vegetation. As marshes sink, suitable habitat for native vegetation decreases, which often results in low quality marsh and even conversion to open water.
Hurricane Sandy left many areas damaged, and flooding exacerbated the existing conditions. Federal disaster funding allowed the refuge to study and determine how to begin improving marsh habitat for priority species.
Project Goals
- Use sediment placement to increase marsh elevation and foster the growth of native vegetation.
- Increase coastal resilience by building up shoreline along the beach to increase buffering potential and protect surrounding communities.
- Remove barriers to restore tidal flow and allow native vegetation to return to impounded areas.
Project Highlights
- Sediment Placement: The refuge chose Good Luck Point (northern part of the refuge) for its first sediment placement project due to its proximity to the dredge material site and road accessibility. They enhanced approximately seven acres of marsh by using a mix of dredged sand and fine materials. Additionally, sand was sprayed along the beach edge, creating a large buffer to wind-driven bay waters. As refuge biologists studied reestablishment of the marsh, it became clear that sediment deposition alone was not enough to foster high marsh vegetative growth. It was determined that organic material was needed to allow plants like smooth cordgrass to thrive, and compost was the most successful. In 2024, the refuge partnered with Ocean County Utilities Authority to deposit small piles of yard waste compost. By the end of the growing season, the sites were lush with native marsh vegetation. The refuge continues to monitor the site and learn about long-term habitat changes.
- Building Resiliency: Raising marsh elevation allows vegetative communities to develop deep root systems, increasing the resiliency of the marsh. Adding sand along the shoreline creates a beach and barrier, protecting the marsh from erosion as the sand withstands wave action better than the salt marsh. The combination of elevation increase and buffering also protects surrounding community infrastructure, such as roads, from flooding and subsidence.
- Barrier Removal: Removal of a low-flow dam opened about eight miles of waterway to natural tidal flow. Upland and wetland habitat on the site was restored through revegetation. Refuge monitoring efforts have demonstrated an increase in species such as the American eel (Anguilla rostrata).
Lessons Learned
By proactively collecting baseline data for the refuge using in-house research, refuge staff were prepared to take advantage of large project funds when they became available. For example, when the Hurricane Sandy recovery funds became available, the refuge applied for funds to hire consultants who helped determine project goals built on the baseline data the refuge had already gathered. This allowed them to determine high and low-risk areas for sediment deposition, ensuring the most successful placement. After the project, the refuge built on previous baseline data by monitoring restoration results and conducting experiments on source materials and vegetative productivity. Through this process, the refuge learned their tidal range is much smaller than most tidal marsh systems.
In order to build effective restoration projects, funding must be available to move beyond sediment placement alone. Building the marsh鈥檚 vegetative structure structure
Something temporarily or permanently constructed, built, or placed; and constructed of natural or manufactured parts including, but not limited to, a building, shed, cabin, porch, bridge, walkway, stair steps, sign, landing, platform, dock, rack, fence, telecommunication device, antennae, fish cleaning table, satellite dish/mount, or well head.
Learn more about structure after building elevation is where the real restoration work takes place, which has been seen in placement of highly organic material like compost. Funding capacity for this was not initially available and is now being raised as part of the overall project. Initially, the refuge did not include enough of each site鈥檚 marshland in their permits, which would have made later permitting processes easier as they expanded the project to additional sites.
Refuge staff recognized that increasing marsh elevation was a priority, and they built partnerships with agencies like the NJ Department of Transportation鈥檚 Maritime Division that had access to dredge materials. For years, sediment was deposited in areas that did not benefit the coastal ecosystem. Placing sediment onto the refuge鈥檚 deteriorating marshes provides a dual benefit for the refuge (increasing marsh elevation), as well as the Department of Transportation (removing sediment from unwanted areas).
Even with strong partnerships, especially long-term ones, not every project aligns well with everyone鈥檚 goals; priorities can shift over time. In these scenarios, it is important to stay true to your objectives; if partner goals differ too much, it is okay to walk away from that specific project and still remain strong partners.
Next Steps
- Evaluate experimental strategies to more rapidly recover high marsh after restoration intervention.
- Partner with the NJ Department of Transportation to seek funding from the National Fish and Wildlife Foundation to continue restoration at a variety of sites on the refuge.
Funding Partners
- Hurricane Sandy Resilience Funds
Resources
CART Lead Authors
- Lyric Buxton, Case Study Writer, USFWS Maintenance and Infrastructure Fellows Program
- Anna Weinberg, CART Coordinator, University of Arizona
Suggested Citation
Buxton, L. and Weinberg, A.K. (2025). 鈥淚ncreasing Marsh Elevation and Hydrologic Connectivity on Edwin B. Forsythe National Wildlife Refuge鈥� CART. Retrieved from /project/increasing-marsh-elevation-connectivity
