Meeting #5 was Coastal Wetlands and Ecology. Members heard presentations from wetland scientist, and WMAB member, Dr. Judith Weis, and Chief of Natural Resources at NYC Dept. Parks and Recreation, Marit Larson. They discussed the state of wetlands in NYC, and what can be done to protect and restore them in the face of increasing climate risks and development pressure. WMAB members then discussed ways to further support the preservation and expansion of waterfront habitats.
Presentation by Dr. Judith Weis on the Sustainability of Salt Marshes
- Salt marshes provide many essential functions, including acting as breeding grounds for fish, a stopping place for migratory birds, water filtration, and flood control and storm surge reduction.
- Salt marshes are also incredibly vulnerable to the effects of climate change. There are limited options for salt marshes when faced with sea level rise; they can move inland, increase in elevation, or be submerged by the rising waters. While some marshes may be able to migrate inland, many do not have the space to due to the presence of roads, parking lots, and buildings. However, through planning, we can find ways for marshes to migrate inland. The tools that would allow for such migration include conservation easements and buyouts/land acquisition.
- Salt marshes may also not get enough sediment to keep up their elevation with the pace of sea level rise. To mitigate this issue, it is possible to add sediment onto the marsh surface to help it elevate. This approach will be required every few years to maintain the marsh, which can be resource and cost intensive.
- Invasive phragmites can provide some benefits, including promoting faster marsh elevation due to their root structure. In the context of climate change and sea level rise, this raises the interesting question of whether to keep Phragmites in place for resiliency purposes or remove them for ecological purposes.
- The economics of marsh restoration, and the limits of conventional cost benefit analyses in capturing the nuanced benefits of these ecosystems was also discussed. Members suggested that there needs to be a better understanding of the benefits associated with storm surge reduction, increased biodiversity and improved public health. The value of an existing wetland compared to a newly constructed wetland also needs to be better understood and communicated. Members also noted that having a better sense of the quantitative value of wetlands could help improve the existing regulatory framework for water quality credits.
- Living shorelines with oysters or mussels at the water edge help to reduce erosion and can provide protection from coastal storms. Living shorelines with oysters or mussels do not typically protect against sea level rise, though living shoreline pilot projects are exploring of ways to incorporate sediment accretion into their design.
Presentation by NYC Department of Parks and Recreation on the draft Wetlands Management Framework (WMF) for NYC
- The NYC Department of Parks and Recreation (DPR) owns 50% of NYC’s wetlands [720 acres of freshwater wetlands, 66 miles of streams, 1,483 acres of salt marsh], and is developing a framework for how to improve wetland management over the next few decades. Wetlands provide a plethora of ecosystem services, from flood protection to public access and recreation, and water quality improvement. However, they are also threatened by filling and fragmentation, sea level rise, pollution and debris, storm water runoff and invasive species.
- The draft Wetland Management Framework (WMF) for New York City lays out a comprehensive roadmap for the preservation, restoration and management of all wetlands and streams in New York City with a focus on those under the jurisdiction of DPR.
- The draft WMF is informed by three decades of restoration experience and new information about the condition of our wetlands. A matrix of ‘condition’ and ‘vulnerability’ of these resources helps to determine priority sites for protection and restoration.
- On the positive side, wetlands have seen an incredible increase in their regulatory protections since the 1970s. Federal and state laws limit direct destruction from filling and development of most wetlands and unavoidable direct impacts to wetlands require mitigation. However, there is potential to improve the quality and extent of mitigation activities. The regulations also do not address on-going loss or ensure future opportunities for conservation, through marsh migration, for example.
- The draft WMF is also a tool for communicating the importance of wetlands and streams in NYC, and provides an overview of past restoration efforts, and current conditions. It also articulates a vision for the future of no net loss of existing wetlands and improving the health of wetland systems that support the people and wildlife of NYC. The draft WMF recommends management and policy actions for each of our wetland types: salt marshes, freshwater wetlands, and streams.
- It seeks to prevent net wetland loss and plan for new wetland areas. It also recognizes the integrated nature of improving wetland health through watershed and storm water management.
- The framework also outlines the funding, maintenance and stewardship requirements associated with maintaining and restoring the health of NYC wetlands.