Tidal wetland habitat assessments on a marine district wide scale have and continue to show degradation of our wetland habitats. In general, the wetland regulatory programs have been doing their job preventing the whole scale fill and build of years past but our wetlands are still being lost at quite alarming rates. The causes of such loss are many: sea level rise, human induced impacts (such as mosquito ditching), nutrient inputs, erosion, and lack of sediment.
As an overall approach to tidal wetland management and improved wetland health, DEC recommends that we focus efforts to monitor, conduct research to determine causes of such loss, and prioritize sites for restoration. To this end, DEC has undertaken several habitat assessments, monitoring, and restoration projects to improve tidal wetland habitat throughout New York. These projects help staff determine the health of tidal wetlands and serve to improve overall wetland habitat.
DEC recommends as part of the overall approach to improve wetland habitats that the following be undertaken.
- Conduct/continue tidal wetlands trends analysis and other marsh health assessments for the entire marine district.
- Where significant (greater than 10% total) losses occur:
- Conduct research to determine the causes.
- Prioritize sites for initiation of marsh restoration. Prioritization metrics could include: acreage, adjacent open space, amount of loss, initiation marsh restoration pilot projects in areas where efforts to minimize causes of loss are coincidently sought.
- Monitor and evaluate restoration projects and efforts to minimize causes of loss. Use information to develop necessary restoration techniques and modify research efforts to determine the causes of marsh loss.
- Where determined feasible, initiate full scale remediation and restoration. This would also involve monitoring and evaluation.
- Seek additional partners and sources of funds to undertake above activities.
- DEC believes that Tidal Wetlands management should be part of a watershed based resource management program and it will work with its partners in all estuary programs toward the appropriate wetland management/restoration strategies. In New York's marine waters, management focus should be in: (a) Long Island Sound, (b) Peconic Estuary, (c) South Shore Estuarine Reserve, (d) New York - New Jersey Harbor Estuary, and (e) Hudson River Estuary. These are established and coordinated partnership efforts.
Monitoring
- Health Assessments: DEC is currently piloting a New York State Tidal Wetland Rapid Assessment that will assess the health of all State owned tidal wetland properties. The assessment incorporates several factors that serve to score the overall health of the properties. Factors include vegetation, salinity, and anthropogenic influences.
- SETs: Surface elevation and marsh accretion at tidal wetlands are monitored by NYSDEC staff at several Surface Elevation Table (SET) benchmark locations around Long Island. These SETs are long-term monitoring devices that provide data on whether tidal wetlands are able to keep pace with projected Sea Level Rise (SLR).
- Trends: Tidal wetland trends analyses study past and present aerial images to determine tidal wetland loss and change. The most recent trends analysis was completed in 2015. Recent tidal wetlands trends analyses have shown that the regulatory program to protect tidal wetlands from the historic "fill and build" damage is extremely successful. Trends analyses over the years have been indicating some alarming changes in our local marshes. The most recent information suggests that marshes are getting wetter. High marsh is converting to low or intertidal marsh and low marsh is converting to unvegetated wetland area and in certain areas marshes are suffering edge erosion.
- Vulnerability Index: NYS is working with USGS to provide state-specific Science Base catalogs adding to the coverage of the National Assessment of Coastal Change Hazards. This project will display drivers and a derived wetland vulnerability index including the ratio between unvegetated and vegetated marsh (UVVR) through GIS and web mapping services. Through this project, we will expand coverage to salt marshes within New York State. This assessment will inform management efforts by identifying the most vulnerable and the most stable areas of estuarine and marine wetlands in New York State, including tidal freshwater wetlands (landward to Troy, NY) within the Hudson River Estuary. The project is estimated to be completed in the Fall/Winter 2019.
Restoration
DEC staff works with partners to plan and implement tidal wetland restoration projects on both State owned and other municipally owned parcels. Restoration projects incorporate various techniques including thin layer deposition, channel modification, and runnel formation.
Fireplace Neck Tidal Wetland Area Restoration: Fireplace Neck, a DEC-owned tidal wetland area on Long Island's south shore, is an impaired 108 acre salt marsh. Historical grid ditching in the 20th century altered the natural flow of water and sediments, in turn leading to habitat loss and conversion of drier high marsh habitat into low marsh and mudflats, making the marsh less resilient to storm events and sea level rise. DEC is investing in the future of Fireplace Neck, and is seeking to develop design interventions that will slow and stem the degradation of the site.
In 2017, the Department was awarded funding from the Ocean and Great Lakes fund to develop a restoration plan for this property. Henningson, Durham & Richardson Architecture and Engineering, P.C. (HDR) was engaged to lead the development of a concept design, in partnership with the DEC, to support the following goals:
- Stabilize the system, limiting further mudflat and open water formation;
- Maintain existing ecological functions and possibly increase habitat values;
- Enable the marsh to sustain the same level of protection and resiliency from large storm events; and
- Support the tidal marsh's ability to adapt to sea-level rise.
DEC is currently working with HDR to finalize the restoration design and to secure all necessary permits. Construction is expected to begin in 2020, or after full funding is secured.
Jamaica Bay Restoration: To offset the loss of tidal marsh in Jamaica Bay, the US Army Corps of Engineers (USACE), working with NYSDEC and other local partner organizations, began a series of projects that added dredged sediment to the marsh surface and planted marsh vegetation to restore tidal marsh on the severely degraded marsh islands. The first project, completed in 2006 and funded by the Port Authority of New York and New Jersey, restored 40 acres of tidal marsh on Elder's Point East. Matching funds from DEC and NYCDEP enabled another 40 acres of restoration on Elder's Point West in 2010 and the restoration of 44 acres of marsh on Yellow Bar Hassock in 2012 to 2013. An additional 16 acres of sand was deposited on Black Wall and 8 acres of sand on Ruler's Bar. Local volunteer groups have engaged in some smaller restoration efforts through the years.
Despite intensive restoration efforts, net loss of tidal marshes continues in Jamaica Bay. Newly restored tidal marshes can take years to become fully functioning ecosystems, so losses to ecosystem services may be greater than the raw decrease in marsh area over the near term.
The UACE has proposed additional restoration and conservation efforts in and around Jamaica Bay as part of the Comprehensive Restoration Plan for the Hudson-Raritan Estuary. The corps seeks funding and authorization to restore 5 additional marsh islands as well as at least 6 sties along the bay perimeter. Should these projects be completed. they will go a long way toward stemming the tide of net marsh loss.
In the 1990's, DEC administered a Jamaica Bay Damages Account (JBDA) for the purpose of 'restoring, replacing or acquiring the equivalent of any natural resources determined to have been injured, destroyed or lost as a result of the release of hazardous substances' from five municipal landfills owned and operated by New York City. A list of 82 tidal wetland acquisition and restoration project proposals was compiled in a 1994 JBDA Report (PDF) and the list was updated in a 2007 JBDA Report (PDF).
Between 2000 and 2003 the DEC and the New York District of the U.S. Army Corps of Engineers (USACOE) conducted a study of the potential for environmental restoration of underwater pits in Jamaica Bay using sediments dredged from the New York-New Jersey Harbor. The study effort culminated in a series of findings and recommendations, which are presented in a formal Findings Statement (PDF). Supporting study reports were reviewed by the Technical Evaluation Panel in development of the Findings Statement.