Habitat and Wildlife Monitoring

Measuring the Impact of Sea Level Rise on Coastal Marshes

With sea level rising at a local rate of approximately 0.1 inch per year, the capacity of marshes to keep pace depends to a large degree on whether sufficient sediments flowing from rivers and coastal embayments are depositing on the marsh surfaces.

Habitat Coordinator Vicky O’Neill measuring the elevation change of coastal marsh sediment at West Pond in Glen Cove, NY. Photo Credit: NYSDEC.

Habitat Coordinator Vicky O’Neill measuring the elevation change of coastal marsh sediment at West Pond in Glen Cove, NY. Photo Credit: NYSDEC.

One way to monitor the ability of marshes to survive the longterm impacts of climate change is through the use of a mechanical measuring device known as the Surface Elevation Table (SET). SETs measure the relative elevation change of wetland sediments. They were first installed in the early 2000s to determine why several wetland complexes were losing vegetation, including the possibility of subsidence, the gradual sinking of peat that supports plants. However, they are also useful to determine how the marshes respond to sea-level rise, an important secondary issue.

There are 16 locations around Long Island Sound where SET devices are installed. Many of these locations include multiple devices. Those installed by NYSDEC and Yale University were funded through LISS.

Eelgrass Aerial Surveys

Aerial surveys for eelgrass are conducted every few years by the National Wetlands Inventory Program (NWI) of the US Fish and Wildlife Service (USFWS) in the eastern end of Long Island Sound. The Long Island Sound Study Habitat Restoration Coordinators track eelgrass restoration projects that are in progress within the watershed by various partners and report the total acres restored annually.

Lacuna vincta on eelgrass off the coast of Fishers Island (Photo courtesy of Cornell Cooperative Extension Marine Program)

Eelgrass, Zostera marina, is a rooted, underwater grass that grows along the shallow coastal waters of bays, estuaries, and beaches in the Northern Hemisphere. Eelgrass meadow habitat provides foraging areas for fish and invertebrates and food for many migratory birds. Healthy eelgrass beds trap sediment and reduce wave energy during storms, improving water quality and protecting coastal areas from erosion.

The extent of the aerial photography acquired on June 28th, 2017 along with the boundary of the Long Island Sound Study

Long Island Sound Fish Trawl Survey

Managing a fishery starts with assessing the abundance and types of fish in the sea. For more than 30 years, the Connecticut Department of Energy and Environmental Protection (CTDEEP) has conducted a trawl survey throughout the Sound to track the size of fish populations. On each trawl, the crew of the research vessel John Dempsey works quickly and precisely to count, weigh, and measure finfish and invertebrates before returning them to the water and moving on to the next site. The samples enable resource managers to compare year to year the relative abundance of dozens of species living in Long Island Sound’s varied habitats.

View a slide show presentation of a fish trawl survey conducted in 2005 (click the arrows in the images above). The collecting method has been consistent since the first survey essential to making sure the data is comparable from year to year.


Alewife Monitoring

Alewives in the Peconic River. Photo by Byron Young.

Restoring the traditional spring spawning run of river herring from the ocean to Long Island Sound to upstream rivers is an important goal for the Long Island Sound Study and many of its partners. In order to make assessments on where to conduct restoration projects, LISS provides training to volunteers who participate in monitoring populations in Westchester and Long Island. It’s important to know the populations of alewives in local streams. Like salmon, herring split their life cycle between salt and freshwater. Most tributaries once supported spring runs of returning river herring. Unfortunately, river herring runs have been decimated by dams, habitat loss, and declining water quality. While remnant populations exist in a few rivers, little is known about their overall status in our area. Documenting existing spawning runs is an important step in the restoration effort.

To register for the training, email Vicky O’Neill at [email protected] or call at (631) 444-0441.

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