Controlling Invasive Species

in Winegar Pond

Blocking the entry of common carp and removing invasive plants has restored Winegar Pond’s natural ecology, improved wildlife habitat, and enhanced outdoor recreation.


Winegar Pond is a 120-acre coastal wetland that sits within the Peshtigo Harbor Unit of the Green Bay West Shores State Wildlife Area. The wetland provides crucial habitat for breeding and migrating waterfowl, as well as spawning grounds for several native species of fish. The wetland is naturally connected to both the Peshtigo River and Lake Michigan, allowing migrating fish to access these spawning grounds. Unfortunately, this positioning also makes Winegar Pond susceptible to spawning populations of invasive common carp, which are enticed by the pond’s warm water and shallow depths. Spawning carp greatly disturb this ecosystem by uprooting native vegetation. The loss of native plant communities degrades water quality, decreases the availability of native fish habitat, and allows invasive plants like phragmites to colonize the area, further displacing native plants and reducing migratory bird nesting success.

Thanks to funding provided by the Great Lakes Restoration Initiative, Ducks Unlimited has worked to stop the introduction of invasive species to restore habitat quality in Winegar Pond. Workers installed aluminum fencing that spans the width and depth of the channels that blocks entrance to the pond. These structures can be deactivated in early spring while native fish species spawn, and activated from May to June when common carp typically enter. This allows the Wisconsin Department of Natural Resources, which manages the Wildlife Area, to deny common carp entry without excluding native fish populations. Workers also applied herbicides to 110 acres of phragmites-infested wetlands, after which treated phragmites stands were burned, mowed, or flooded to help ensure eradication.

Resource Challenges Addressed

  • Lack of coastal wetland habitat
  • Degraded native wildlife and plant communities
  • Invasive plant and wildlife populations


Invasive reeds on the edge of a pond

Federal Great Lakes restoration grants have allowed wildlife managers to install seasonal fencing to keep non-native fish out of Winegar Pond. The grant has also allowed workers to control invasive phragmites (pictured above at a different location) to help restore habitat. Credit: Wikimedia Commons.

Results and Accomplishments

The project was completed in 2015, and after several growing seasons, the formerly struggling coastal wetland has seen a resurgence in its native waterfowl and shorebird populations. This restored habitat enhances outdoor recreational opportunities for bird watchers from across the region. The eradication of invasive phragmites has resulted in the reestablishment of wild rice populations.