Corps of Engineers, partners start oyster restoration in the Tred Avon River, as restoration in Harris Creek nears completion

Published May 6, 2015

BALTIMORE - The U.S. Army Corps of Engineers, Baltimore District, and partners began constructing oyster reefs in the Tred Avon River, April 30, 2015, just as restoration on 370 acres wraps up in Harris Creek. These efforts are part of the Maryland statewide oyster restoration program that identifies tributaries in the Chesapeake Bay for restoration.

"We are committed to improving the health of the Chesapeake Bay through collaborative environmental restoration efforts, including oyster restoration," said Col. Trey Jordan, Baltimore District commander. "The progress we have made -- and continue to make -- demonstrates the immeasurable value in working together to achieve a common goal."

Tred Avon River

Restoration in the Tred Avon River this spring includes constructing up to 24 acres of approximately 1-foot reefs in water 9 to 20 feet deep. Mixed-shell materials from coastal processing plants and rock quarried in Havre de Grace, Maryland, will be used to create the reefs. In total, 147 acres are planned for restoration in the Tred Avon River.

The efforts on the Tred Avon come after the Corps of Engineers and partners met with the Maryland's Watermen Association to discuss a path forward for working more closely together throughout the planning and restoration process. Following a series of meetings and visits to the restoration sites with the watermen, the interagency team is limiting the use of rock planned for this construction effort to three sites in the Tred Avon River to minimize impacts to trotlining by crabbers. The remaining reef sites planned for this spring will be made of mixed shell that was initially to be placed at Harris Creek. There is not sufficient natural shell available to restore oyster habitat in the Bay; therefore, other materials like rock need to be used to construct reefs. These alternate materials have proven to be successful at our restoration sites. 

Harris Creek

Harris Creek will be the first tributary where restoration plans are completed. Through the interagency partnership, the State of Maryland has planted more than a billion oysters in the Harris Creek Sanctuary since 2011. Due to this restoration, areas with less than one oyster per square meter now have upward of 25 oysters per square meter. The reefs will be monitored to continue to assess the restoration progress.

Benefits of Oyster Restoration

Oyster populations in the Chesapeake Bay have declined considerably in the last century, largely due to parasitic diseases, overharvesting, declining water quality, and loss of habitat. Less than one percent remains of historic oyster populations.

Oyster restoration is important because oysters provide a number of environmental benefits, including reef habitat that is significant to the Bay ecosystem for animals like blue crabs and fish. Additionally, oysters are filter feeders that improve water quality ─ a single adult oyster can filter up to 50 gallons of water in 24 hours. Oysters also help with cycling nutrients, reducing sediment, and storing carbon long-term to help mitigate global warming.

Restoration only takes place in pre-existing sanctuaries, as established by the Maryland Department of Natural Resources (DNR). However, the objective is to provide baby oysters that settle not only within the sanctuary, but also on public shellfish fishery areas outside of the sanctuaries.


Maryland DNR is the non-federal sponsor for the Corps of Engineers’ oyster restoration activities in Maryland. Additional project partners include the National Oceanic and Atmospheric Administration (NOAA) and the Oyster Recovery Partnership (ORP).

There are two important documents that guide how oyster restoration actions are conducted in the Maryland portion of the Bay. The Native Oyster Restoration Master Plan (2012) ( guides those projects that are funded for Corps of Engineers construction. The state’s restoration actions are conducted in accordance with Maryland’s 10-Point Oyster Restoration Plan (DNR 2010) found at Federal actions are supported by the National Environmental Policy Act documents that have been completed to date.

The construction contract for work in Harris Creek and the Tred Avon River was awarded to ARGO Systems LLC, July 2014. ARGO Systems LLC is a Service- Disabled, Veteran-Owned Small Business out of Hanover, Maryland.

Restoration plans are subject to availability of funding and reef material.

For more information, including plans and environmental assessments for the program, high-resolution pictures, construction site maps indicating the revised reef locations, and Q&As, visit


More media contacts:

Karis King (DNR), 410-260-8001,

Kim Couranz (NOAA), 410-267-5673 or

Kara Muzia (ORP), 410-990-4970 or




Sarah Gross

Release no. 050615-001