SALT MARSH MOSQUITO DITCHES ON FIRE ISLAND, NY:SEDIMENTATION RATE, NEKTON COMMUNITY, AND IMPLICATIONS FORRESTORATION

Corman, Sarah

Mosquito ditches are man-made features designed to provide physical and biological control over the breeding of salt marsh mosquitoes. These ditches were dug beginning in the early 1900’s, but became increasingly widespread in the 1930’s as a part of public works projects. While this method has been mostly replaced by other techniques, ditches remain a ubiquitous feature in Northeastern United States salt marshes. The present study was concerned with mosquito ditches on Fire Island, New York (USA). A ten-kilometer stretch on Fire Island, including salt marsh habitat, was given a Federal Wilderness Area designation in 1980. As a result, the National Park Service seeks to remove evidence of human influence on this marsh system. Because the mosquito ditches are an obvious imprint of human influence, there has been interest in a restoration effort to remove the ditches, likely by filling them with sediment. In consideration of this restoration, the National Park Service sought to understand the role of ditches as habitat for fish and decapod crustaceans and the rate of natural ditch filling, perhaps supporting or refuting a passive restoration alternative. There was also interest in determining the total length and volume of ditches present in this marsh area to serve as a guide to seeking sources of fill material if that should become a feasible restoration alternative...