Delta Marsh Carp Exclusion 2012-2013

Final Project Report: Delta Marsh Carp Exclusion 2012-2013

Check out this CTV Winnipeg video about DUC’s Delta Marsh Carp Exclusion project: 
Plan to keep invasive carp out of marsh appears successful”


Goals and Objectives

Since the first half of the twentieth century, common carp, an alien invasive fish species, have dominated the waters of Lake
Manitoba and the Delta Marshes. The breeding and feeding activities of these large and aggressive invaders has increased
turbidity, lowered water quality, significantly reduced aquatic native vegetation and increased erosion. This degradation of the
basic elements of the marsh has consequently resulted in severely degraded habitat conditions for waterfowl and other water
birds, native fish, mammals and amphibians. Prior to this degradation, Delta Marsh was world renowned for waterfowling, bird
watching, outfitting and guiding. Over the years, this once internationally significant wetland has deteriorated to the point where
it is no longer considered a hunting destination, important water bird staging area or waterfowl breeding area.

This project will exclude common carp from the marsh while allowing access to native fish species. The result will be a near
immediate improvement of water clarity and plant growth which will form the foundation for the marsh’s return to health and the
provision of habitat for fish, waterfowl and other wildlife. Other ecological improvements resulting from the restoration include
increased carbon storage due to increased submergent and emergent plant growth, improved water quality as greater nutrient
loads are taken up through the plants from the water, and reduced sedimentation as erosion declines due to the reduction in
wave action as a result of the increased vegetation.

The goal of this project is:

1) Restore the ecological integrity of Delta Marsh.

 

Activities

October 2012-March 2013: Exclude Common Carp from the marsh while still allowing access for desirable fish species by constructing
6 strategically located control structures on access points to Delta Marsh complete with removable screens.
 

Benefits to Waterfowl, Wetlands-Associated Species, and/or Other Wildlife

The rehabilitated Delta Marsh will better support breeding waterfowl and other water birds by increasing vegetative cover and food supply,
as well as restore food supplies that are attractive and necessary for moulting and staging migratory water birds.
 

Relevance to Habitat Planning, Decision Making and/or Management

In addition to restoring habitat for wildlife, the project will demonstrate the valuable role that wetlands play in purifying water. The project will
enhance the economic condition of the area as waterfowl return, and the resultant increase in hunting interest encourages tourism, guiding
and outfitting in the area. This wetland value will be clearly demonstrated to local residents and to local, provincial and federal government
officials.

This carp exclusion project is considered one element of a comprehensive plan to restore Delta Marsh. Future and concurrent work will include
scientific research into the factors contributing to poor water quality, and recommendations for recovery through Beneficial Management Practices.
As well, water level management of Lake Manitoba and its effect on Delta Marsh will be studied, and recommendations made. The expansion of
hybrid cattail will be investigated and methods tested to control or limit its growth. Also, some additional land will be secured through conservation
easement or acquisition to increase security and function of the marsh.
 

Project Location

The project is located at the southern edge of Lake Manitoba in the RM of Portage la Prairie, Manitoba. The land is generally flat, dominated by
native grassland and wetland vegetation. It is bordered by annual cropland, with potatoes, wheat and canola the predominant crops. 

The majority of the marsh is open to migratory game bird hunting, though some lies on private land and would require permission from the landowner.
A large portion of the project lies within the Delta Marsh Wildlife Management Area and is open to hunting. A portion of the west marsh is designated
as a Game Bird Refuge due to the research work being conducted there by the University of Manitoba.

Delta Marsh is noted as a Ramsar Wetland of International Significance, a Canadian Important Bird Area, a Manitoba Heritage Marsh and a Manitoba
Wildlife Management Area.
 

Project Contact

For more information on this project, please contact Rick Andrews, Head of Wetland Restoration MB, Ducks Unlimited Canada, Brandon, MB.