WESPEN Online Order Form print this page
US Fish & Wildlife Service FieldNotes

Cleaning Up the Past: Ditch Remediation at Rachel Carson & Parker River National Wildlife Refuges

Region 5, August 2, 2013
An experimental site undergoing remediation.
An experimental site undergoing remediation. - Photo Credit: n/a

Before the 20th century, salt marshes along the east coast of the United States were used heavily for agriculture. The farmers are long gone, but their impacts on the marshes remain. One of these impacts is ditching. Farmers dug long parallel ditches leading from a tidal creek toward the upland in order to make it easier to harvest salt marsh hay. In the 1900s, ditches were used to drain the marsh in attempts to reduce mosquito production.
Like many other manmade “improvements”, ditching salt marshes has a number of unintended negative effects that disrupt natural processes which otherwise maintain marsh elevation.
At both Rachel Carson and Parker River NWRs, the Land Management Research and Demonstration program, with support from a North American Wetlands Conservation Act (NAWCA) grant under the auspices of Ducks Unlimited, is developing an innovative restoration technique aimed at remediating or “healing” such ditches. With our partners, we’re using mowed salt hay (Spartina patens) to fill ditches in experimental sites. The idea is to encourage the formation of marsh peat by elevating the floor of the ditch and trapping sediment and seeds in the hay. Over time as sediment builds up and plants begin to grow, the ditch should disappear. We are also matching this effort to remove ditch drainage with efforts to restore more natural tidal ebb and flows. We do this by causing meanders to form in remaining ditches and designing new channels to mimic natural tidal channels. Our goal is to increase resilience to climate change by removing anthropogenic stressors associated with salt marsh ditching.


For Additional Information Contact:
Susan C. Adamowicz, Ph.D.
LMRD Biologist
Rachel Carson NWR
321 Port Rd.
Wells, ME 04090
207-646-9226 x31

Contact Info: Stephanie Petrus, 207-646-9226, stephanie_petrus@fws.gov