The Department of Environmental Protection on Thursday unveiled its new informational website and mapping tool to help the public, stakeholders, and government officials advance work to make coastal wetlands more resilient to sea-level rise.
New Jersey has some 200,000 acres of coastal wetlands that support diverse and ecologically sensitive ecosystems. These wetlands also help buffer coastal communities from the potentially devastating impacts of storms.
Data derived from the development of the tool shows that 61% of the state’s coastal wetlands may be at risk of being lost because the processes that help create them are not able to keep pace with the accelerating pace of sea-level rise, the DEP said. This situation potentially jeopardizes the ecological diversity found in robust wetlands and the important storm-surge protection wetlands provide coastal communities.
“By pinpointing areas where sea-level rise is having the most profound localized impacts on tidal wetlands, this tool will improve local decision-making on wetlands restoration and enhancement projects that will better protect natural resources and coastal communities,” DEP Commissioner Shawn M. LaTourette said.
Coastal wetlands respond differently to sea-level rise due to a variety of factors, including local topography, water flow and currents, and the rate of sea-level rise. Moreover, there can be significant variability in localized wetland impacts.
Tidal wetlands can naturally gain elevation through sediment and organic deposition during tide cycles and flooded conditions. In many parts of New Jersey, however, wetlands are not gaining elevation at a rate that equals or exceeds local rates of sea-level rise.
When wetland surfaces do not keep pace with sea-level rise rates, high marsh may convert to low-marsh and low-marsh to mud flats or open water. This results in a loss of valuable habitat for many birds and fish, economic losses for commercial and recreational fisheries, and loss of natural flood and storm-surge protection for communities and infrastructure.
“Elevation changes are the most fundamental component of tidal wetland resilience,” said Dr. LeeAnn Haaf, Estuary Science Assistant Director for the Partnership for the Delaware Estuary. “This new website and mapping tool are aimed at answering the question: Is marsh elevation keeping pace with sea-level rise?”
In 2018, the Murphy administration formed the New Jersey Tidal Wetland Monitoring Network to track current conditions and trends relative to tidal wetlands to improve the resilience of coastal communities and ecosystems. Led by science and research staff at the DEP, the network is comprised of more than 15 research organizations, universities, and nonprofits. The data the network develops supports informed wetland restoration and protection management efforts.
In developing the new website and tool, the network used long-term monitoring datasets to make more accurate assessments of how New Jersey’s coastal wetlands are responding to accelerating rates of sea-level rise.
The network measured marsh elevation change and sedimentation rates at Surface Elevation Table (SET) stations throughout the state. At each SET station, the marsh-elevation change rate was compared to long-term and recent sea-level rise rates from the nearest National Oceanic and Atmospheric Administration National (NOAA) Water Level Observation Network station.
Thirty-nine percent of the stations analyzed experienced elevation change rates higher than the recent rate of sea-level rise, which indicates that 61% of the stations and, therefore, the surrounding wetlands, are potentially vulnerable to losses from sea-level rise, the DEP said.
Potentially vulnerable tidal wetland sites can be found along the ocean (including Sandy Hook, Forked River, Island Beach, parts of Barnegat and Great bays, and Stone Harbor, among others), as well as along the tidal Delaware Estuary, from Delaware Bay (including Dennis Creek, Dividing Creek and parts of Stow Creek), and along the Delaware River to Trenton.
DEP said New Jersey’s relative sea levels are rising at a rate that is about twice the global average because of the effects of climate change caused by greenhouse gas emissions. Under a moderate greenhouse gas emissions scenario, New Jersey is projected to experience a likely range of 2 to 5 feet of sea-level rise by 2100, DEP said.
NJBIA Deputy Chief of Government Affairs Ray Cantor said Thursday that NJBIA, the federal government, and most other climate experts believe New Jersey’s sea level rise will be in the 1 to 3-foot range this century.
