At first glance they don’t seem like much, but the muddy, grass-covered salt marshes that line the shores of Long Island are actually some of the most productive places on Earth. Not only do they rival both tropical rainforests and cultivated land, but they also provide habitat for countless species of birds, fish and crustaceans.

However, with sea levels on the rise, the future of Long Island’s coastal wetlands is increasingly uncertain.

That’s why Dr. Nicole Maher, a wetlands specialist for The Nature Conservancy’s Long Island Chapter, is working with state, county and federal officials and local towns to determine whether New York’s wetlands are adapting or drowning in response to rising waters.

Feeling the Pinch

Healthy salt marshes respond to sea-level rise by accumulating sediment and migrating landward as tidal waters inundate areas that were once dry. But human development along the coast can impede this movement, ultimately trapping the marsh between the open ocean and the structure that stands in the way. Pollution can also damage the roots of wetland plants so that they are not thick enough to rise above higher water levels.

To keep track of local marshes, Maher has set up permanent monitoring stations, called surface elevation tables, across Long Island and near New York City. At each location, Maher spreads a thin layer of white powdery material on the surface of an area of marsh peat.

She returns three times a year to measure changes in the elevation of the marsh surface, the depth of material that has accumulated on top of the base level, and any changes in vegetation. The growth rates are then compared to the rates of sea-level rise measured by the National Oceanic and Atmospheric Administration at Montauk Point.

“Over time, this project will give us some baseline knowledge of whether our wetlands are keeping up with sea-level rise on Long Island,” explains Maher.

“Right now, anecdotal evidence suggests that they are not. By using the data collected here, eventually we hope to alleviate some of the threats and better manage our coastal areas to facilitate migration.” 

Migrating Marshes

The migration and survival of coastal wetlands is critical to the health and safety of communities across Long Island. Healthy, functioning wetlands protect coastal water quality, provide food and habitat for many recreationally and commercially harvested species, and act as buffers to protect the coastline from the brunt of storms.

In sum, the loss of healthy salt marshes impairs the health of the entire coastal ecosystem and all of the recreational and economic activities that depend on it. While wetlands have been called many things, from “kidneys of the coast” to “nature’s sponges,” one thing scientists hope they aren’t called anytime soon is “history.”

Nature picture credits (top to bottom, left to right): Photo © The Nature Conservancy (wetlands); Photo © The Nature Conservancy (map).