ASSESSMENT OF
HYDROLOGIC ALTERATION ON SALT MARSH COMMUNITIES ALONG THE ATLANTIC COAST
James-Pirri*, M.-J. 1, R.
M. Erwin2, D. Prosser3, and J. Taylor4
1Graduate
School of Oceanography, University of Rhode Island, Narragansett, RI 02882; 2USGS
Patuxent Wildlife Research Center, Department of
Environmental Sciences, University of Virginia, Charlottesville, VA 22903; 3USGS
Patuxent Wildlife Research Center, Beltsville Lab,
Beltsville, MD 20705; 4US Fish and Wildlife Service, Region 5,
Newington, NH 03801.
ABSTRACT
We evaluated the initial responses of salt marsh
communities to hydrologic alteration (OMWM and ditch plugging) at 5 National
Wildlife Refuges (21 sites) from Massachusetts to Delaware using a BACI design. At each Refuge we selected pairs of sites that
included treatment (hydrologically altered) marsh and
a control marsh. All marsh pairs were monitored prior to alteration and for 2
years following hydrologic alteration. Monitored parameters included vegetation
community structure, soil salinity, water table level, mosquito production,
nekton (fish and crustaceans) community structure, and bird use. In general
there were no consistent, predictable patterns in the salt marsh ecosystem
responses to hydrologic alteration, although water table levels and nekton
community composition were the parameters most influenced by the alterations.
At many sites there was no response at all to hydrologic alteration as
indicated by a lack of statistical significance for the measured variable
before versus after the alteration.
Examples of the types of detectable changes that were observed will be
highlighted.