Department of Environmental Conservation

D E C banner

Tidal Wetlands Trends

Trends Analysis

The Long Island Tidal Wetlands Trends Analysis measures wetlands loss and changes in marsh condition within the Long Island Sound, Peconic, and South Shore estuaries including all or parts of Westchester, Bronx, Queens, Nassau, and Suffolk Counties. The results of this project are intended for use by environmental managers, conservation advocates and elected officials across a variety of regulatory agencies, environmental organizations, and governments.

Overall, Long Island's estuaries have lost approximately 2700 acres of native intertidal, high marsh, and coastal fresh marsh communities over the study period of 34 years (1974 and 2005/2008). This acreage accounted for between 10 and 100 percent loss of individual marshes.

Marsh loss was observed as:

  • The conversion of high marsh to intertidal marsh, and retreat of the seaward edge of the marsh,
  • The formation of pannes, ponds, and mudflats, as well as the widening of ditches within marshes, and
  • The intrusion of Phragmites australis

The complete report is available:

A more discrete analysis has been conducted for Nassau and Suffolk Counties on Long Island and Jamaica Bay.

Tidal Wetlands Loss Workshop

The proceedings for the 2014 Long Island Sound Tidal Wetlands Loss Workshop is now available online at the Long Island Sound Study (link leaving DEC's website).


More about Tidal Wetlands Trends: