Deer in Spring Landscape

Maryland Marsh Restoration/Nutria Project Partnership: Partnership & Pilot Program FAQs

What is the Maryland Nutria Partnership?

The Partnership consists of 26 federal, state, and private organizations. Its goals are:

  1. to determine whether or not it is feasible to eradicate nutria on Maryland's Eastern Shore and if so, how to do it and how much it will cost/unit;

  2. to restore marsh habitats; and

  3. to promote public understanding of the importance of preserving Maryland's wetlands.

photograph of nutriaWhen did the Partnership begin?

In 1997, the Maryland Department of Natural (DNR) Resources and the U.S. Fish and Wildlife Service (USFWS) coordinated a Nutria Control Summit, which resulted in the formation of the Partnership. There were 17 initial partners. The partnership grew to include the 26 partners involved today.

What is the Marsh Restoration/Nutria Project Partnership?

The Project is in two Phases. The Partnership has completed a 3-year pilot project (Phase I) to assess nutria populations in Dorchester County on three sites: Blackwater National Wildlife Refuge (federal), Fishing Bay Wildlife Management Area (state), and Tudor Farms, Inc. (private). Each site contained an experimental plot, a control plot, a buffer plot; each about 400 acres.

The objectives of the pilot project were:

  1. to establish an estimate of nutria populations and animal densities in the three study areas;

  2. to monitor nutria behavior and movement, especially in response to intensive trapping; and

  3. to evaluate the reproductive and overall health of the population, especially in response to intensive trapping on the study sites.

The Pilot Project proposal was completed in 1998. It was implemented in 1999 was completed in 2002.

In 2002, the Partnership Management Team, which includes the USFWS, MD DNR, the U.S. Department of Agricultures Wildlife Services, the U.S. Army Corps of Engineers (ACE), the U.S. Geological Survey's Cooperative Fish and Wildlife Research Unit, and the University of Maryland Eastern Shore, began Phase II. During Phase II, 14 trappers are setting various traps across grids of 40 acres throughout the three study areas. They are also working with surrounding landowners to trap on private properties that are adjacent to these areas. Meanwhile, the ACE is testing sediment spraying and planting of 3-square bulrush on Blackwater National Wildlife Refuge. The goals of Phase II are:

  1. to determine whether or not nutria can be eradicated from the three original study areas and if so, how to do is and what it will cost/unit and

  2. to determine the best approach to marsh restoration in areas where nutria have been removed and where nutria are still present.

How is the pilot project funded?

In 1998, the U.S. Congress authorized $2.9 million for Phase I over three years. The pilot project was also funded through grants from the U.S. Dept. of Agriculture (1890 Institution Teaching and Research Capacity Building Grants Program), the National Fish and Wildlife Foundation. The Maryland DNR continues to provide funds, staff and supplies to the project. The University of Maryland Eastern Shore and the Maryland Cooperative Fish and Wildlife Research Unit, Tudor Farms Inc., and the U.S. Department of Interior's Fish and Wildlife Service and Geological Survey also provide critical staff and other in-kind contributions to the project.

The total cost of Phase I is estimated to be $4.2 million. The cost of Phase II is estimated to be $4 million/year for 2-5 years. In 2002, the House of Representatives passed a measure authorizing this funding, and the bill is in Senate committee. The FY03 Interior Appropriations include significant funding for the project. Grant requests from the National Wetland Conservation Program and other sources have been submitted and the Partnership continues to contribute funds.

The Marsh Restoration/Nutria Project consists of:

Behavioral/Population Research
Nutria were trapped and fitted with radio collars so that biologists can track their movements. This data helped the Partnership establish a grid size of 40 acres across the marsh to test trapping strategies. Forty acres was found to be the average movement of nutria per day. The data also helped us to understand that nutria move more in spring and fall and less in winter and summer. Animals were marked so that they could be recorded when they are recaptured. Although the recording of marked animals continued in Phase II, experience has taught us that it is difficult to accurately estimate nutria populations because of variations in fecundity and mortality.

Reproductive Research
It is possible that nutria could increase the number of young per litter and the frequency of breeding in response to declining populations. Research is being conducted to help biologists understand nutria reproduction biology. This research has been conducted in both unharvested and in harvested populations. Animals used in the study are also evaluated for physical condition and overall heath.

Testing of Trapping Methods/ Population Control Strategies
Fourteen trappers are now trapping in 40 acre grids across the entire marsh in Blackwater National Wildlife Refuge, Fishing Bay Wildlife Management Area, and Tudor Farms. Various traps and trapping strategies are being tested for their efficiency in capturing nutria under various natural conditions. Trapping success will be monitored by measuring reduction of nutria by catch per unit effort in an initial, intensive harvest and a second sweep through an area after several months as well as surveys for nutria sign in trapped polygons to determine whether nutria were eradicated, and the impact of trapping techniques on non-target animals.

Marsh Restoration
Nutria have contributed to the loss of thousands of acres of marsh in and around Blackwater National Wildlife Refuge. The U.S. Army Corps of Engineers is conducting a pilot study for the summer of 2002 to study the feasibility and cost of restoring the marsh in these areas where marsh has disappeared. The pilot study explores the impact of the presence of nutria in the study sites, the feasibility of adding soil to replace eroded sediment that supports plant growth, and the planting of 3-square bulrush.

The U.S. Army Corps of Engineers will use the results of this study to implement a 4-year planned marsh restoration project, potentially covering 150 acres of denuded marsh in the Blackwater National Wildlife Refuge.

For more information, contact:

Jonathan McKnight
Associate Director, Habitat Conservation
Wildlife & Heritage Service
Maryland Dept. of Natural Resources
580 Taylor Ave., E-1
Annapolis, MD 21401
(410) 260-8539
Toll-free in Maryland:
1-877-620-8DNR, Ext. 8539