Chincoteague National Wildlife Refuge

Ecology and Management

Most of the impoundments at Chincoteague NWR were constructed in the 1950s and 1960’s to provide migratory bird protection, with the primary purpose of providing waterfowl migration and wintering habitat. When first established the Refuge focused more on single species management. Today, however, the Refuge manages impoundments for a suite of wildlife throughout the year. The impoundments also supply numerous habitat benefits, including wintering/migratory habitat for waterfowl; fresh/brackish vegetation roots and seed as food for wintering waterfowl; food sources for waterbirds of conservation concern such as snowy egret, glossy ibis, Forster’s and gull-billed terns; and shorebird migratory stopover habitat for many species of conservation concern, including short-billed dowitcher, dunlin, and semipalmated sandpiper. The Refuge also manages habitat for American black ducks, as part of a long-term effort, in compliance with the North American Waterfowl Management Plan. The impoundments are also managed for a range of aquatic species and other species of conservation concern. Several federal and state endangered and threatened species are also found within the Refuge. They include: piping plover (FT), red knot (FT), roseate tern (FE), Delmarva fox squirrel, Northern long-eared bat (FT), gull-billed tern (ST), Wilson’s plover (SE), and peregrine falcon (ST).

To support the wide array of bird species found at the Refuge, impoundment water levels are closely managed to provide adequate food, in the form of vegetation (seed or roots) and/or aquatic invertebrates, fresh water, and loafing areas. However, all Refuge impoundment management strategies depend entirely on precipitation as their sole source of freshwater for the generation of fresh/brackish water plants, and gravity or evaporation for drawdown. Both mechanisms limit management capabilities. Tidal cycles and strong coastal storm events, especially nor’easters and hurricanes, further challenge the attainment of management goals for impoundments. Non-native Phragmites also poses a management challenge.

Vulnerability

Chincoteague’s impoundments are located between mean high and spring high tide and abut upland areas as well as fresh or brackish marshes not affected by tides. Because the impoundments generally are located above the high tide level, estuarine water cannot enter them. However, tidal influx can occur through the Virginia Creek water control structure (WCS) into Old Fields Impoundment. During severe weather and extreme high tides, overwash reaches impoundments from the sea and Bay side; Black Duck (A) Pool, Snow Goose (B-South) Pool, Shoveler (B-North) Pool, Mallard (C) Pool, Pintail (D) Pool, Swan Cove (F) Pool, Wash Flats, and Old Fields impoundments are most susceptible. As noted previously, because the impoundments depend on precipitation for freshwater inputs, tidal cycles and strong coastal storm events, especially nor’easters and hurricanes, challenge the attainment of management goals for impoundments. Additionally, as sea level continues to rise and more frequent overwash events occur, the Refuge expects damage to dikes and other impoundment infrastructure. Maintaining water depths at desirable levels may also become more difficult.

Human Value

Chincoteague NWR provides significant recreation and education opportunities for visitors. Specifically, the impoundments concentrate large flocks of birds, providing wildlife viewing, and opportunities for photography, education, and interpretation. In 2010, approximately 1.4 million people visited the Refuge. In terms of education, the Refuge offers a wide range of programming, including day camps to family programs, and undergraduate and graduate research opportunities. The Refuge also works with local K to 12 schools, communities, and educational organizations to provide classroom and hands-on programs both on and off the refuge for youth. Teacher workshops and Teacher Guided Learning Opportunities are also available.

Acknowledgements

We are grateful to Kevin Holcomb, USFWS Chincoteague National Wildlife Refuge, for providing helpful information used on this page.

Literature Resources