Chesapeake Bay Field Office
Northeast Region


New Report Shows Annual Loss of 59,000 Acres of Wetlands in Coastal Watersheds ...continued

The Maryland Coastal Bays region has lost wetlands to agriculture, development, grid ditches, and other human activities. Ditches were cut from high marsh water bodies and linked to their tidal sources, changing the natural hydrology of the salt marsh system.

After ditches were created, pools and pannes were drained and subject to daily high and low tides. Permanent water bodies were drained, and in some cases, filled in over time. The lack of stable water levels destroyed marsh habitat essential to various wetland dependent birds.

Mosquito ditch before and after plugging, Photo left; Dan Murphy. Photo right: Julie Slacum
E.A.Vaughn Wildlife Management Area (WMA), located in Worcester County in the Maryland Coastal Bays region. Before, left. After, right.
Credit: Dan Murphy, USFWS. Credit: Julie Slacum, USFWS


To restore the natural coastal salt marsh, 35 ditch plugs were installed in ditches at elevations equal to the surrounding marsh. By stabilizing water levels, permanent and semi-permanent water bodies emerged, resulting in an increase in aquatic invertebrates, fish and submerged aquatic vegetation (SAV) common to high marsh areas. These in turn will provide food and habitat needed by wetland dependent birds.

This area is an important area for breeding and wintering waterfowl. The wetlands support American black duck, American widgeon, Atlantic brant, bufflehead, Canada goose, canvasback, gadwall, scaup, greater snow goose, mallard, Northern pintail, and red-breasted merganser. Coastal salt marshes also support black rail, Henslow's sparrow, salt marsh sparrow, and seaside sparrow.

Photo of a blue crab. USFWS Northern Shoveler. Credit: Donna Dewhurst
Canada Goose. Credit: Donna Dewhurst Snow Geese. Credit: Dave Menke
Blue-winged teal. Credit: Dave Menke

A sampling of critters that will benefit from improved wetlands.

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Top row: Blue crab, USFWS, Northern Shoveler. Credit: Donna Dewhurst
Middle row: Canada Goose. Credit: LaVonda Walton, Snow geese. Credit: Dave Menke
Left: Blue-winged teal. Credit: Dave Menke

The project is a partnership the Maryland Department of Natural Resources, Maryland Department of the Environment, and Maryland Department of Agriculture-Mosquito Control, Ducks Unlimited and the Chesapeake Bay Field office.

The Partners for Fish and Wildlife Program and Coastal Program provide financial and technical assistance to partners, including communities and private landowners, so that they can conserve wetlands, streams and other habitats. For more information or assistance, please contact Rich Starr, Partners for Fish and Wildlife Program, at 410/573-4518 or Dan Murphy, Coastal Program, at 410/573-4521

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Want to know more?

Status and Trends of Wetlands in the Coastal Watersheds of the Eastern United States, 1998 to 2004 is posted online at

View the U.S. Fish and Wiildlife Service news release.

Last updated: January 6, 2011