The Great Wicomico River in Northumberland County is one of the 10 rivers in the Chesapeake Bay region to be part of the oyster habitat restoration described by NOAA as “world’s largest oyster restoration project.” Writes NOAA,
The 2014 Chesapeake Bay Watershed Agreement, which guides the work of the Chesapeake Bay Program, calls for state and federal partners to “restore native oyster habitat and populations in 10 Bay tributaries by 2025, and ensure their protection” (hereafter, “Ten Tributaries initiative”). Five tributaries are being restored in Maryland and five in Virginia.
So why the Great Wicomico River? The US Army Corps of Engineers (USACE) found it had attributes which would make habitat restoration possible. In Habitat suitability index and performance of USACE sanctuary reefs in the Great Wicomico River (15 May 2013) (PDF), USACE explains:
In 2004, the U. S. Army Corps of Engineers, in conjunction with the Virginia Institute of Marine Science and other federal and state agencies, constructed 85 acres of “no take” sanctuary oyster reef habitat in the Great Wicomico River, a small tidal tributary of the Chesapeake Bay, located approximately 60 miles northeast of Richmond, Va.
This waterway was chosen because it is a “trap” estuary where water movement promotes the circulation and eventual settling of larvae generated by the spawning of oysters living within the river’s reef network. It had a history of high oyster spatsets (baby oysters are known as “spat”) relative to most of the rest of the bay due to this.
Modern-day modeling has identified that it has favorable hydrodynamics for oyster larval retention – which is what gives it the “trap” nature noted decades earlier. The Corps focuses on developing a sufficient network of oyster reefs to reestablish the historic population by producing enough oyster larvae to replenish the constructed reefs and to be carried by currents to other locations in the river.
Monitoring data provides strong evidence that this has occurred, with a positive increase in river-wide recruitment first noted in 2006 and continuing today. In fact, in the GWR, 2012 had the highest oyster recruitment ever observed in the Bay since monitoring began in the 1940s.
Some years later, the Western Shore Oyster Restoration Workgroup under the Chesapeake Bay Program’s Sustainable Fisheries Goal Implementation Team wrote Great Wicomico River Oyster Restoration Tributary Plan -- A Blueprint for Restoring Oyster Populations per the 2014 Chesapeake Bay Watershed Agreement December 2020 (PDF). The group reports that “past restoration efforts by the U.S. Army Corps of Engineers (USACE), and reefs managed by the Virginia Marine Resources Commission (VMRC)” successfully addressed approximately 100 acres of the 124 acre goal. The outstanding 22.5 acres are to be addressed before the 2025 deadline.
So how will the remaining 22.5 acres of habitat be restored? Again, the Western Shore Oyster Restoration Workgroup,
The predominant restoration technique for the proposed reefs will likely be placing shell, stone, or other substrate onto the proposed site in either a striped configuration or covering the entire site. Natural oyster recruitment is generally high in the river, and the Workgroup expects reef substrate to self-seed with juvenile oysters, although some spat-on-shell may be planted onto some reefs. Reefs will likely be constructed using varying amounts of substrate, depending on existing river bottom type. Where suitable shell bottom already exists, lesser amounts of substrate can be used for reef construction. Conversely, in areas with hard river bottom but little or no shell substrate, more substrate (piled higher) will be required.
TL;DR? Watch Great Wicomico River Oyster Reef Building, B-roll of Contractors using heavy equipment to place fossilized oyster shell onto sanctuary reefs in the Great Wicomico River in Burgess, Virginia. Includes interview with Susan Conner, Norfolk District environmental analysis section chief.
As if this project is not cool enough, NOAA says that the restoration to date is larger than two square miles. That is equivalent to 2,300 acres or more than 1,000 football fields. Read more about this super successful and important project in Chesapeake Bay Oyster Reef Restoration Acreage Surpasses 2 Square Miles.
Photo at top: By Mark Haviland; Oyster Restoration, GREAT WICOMICO RIVER, Va. -- Researchers with the U.S. Army Corps of Engineers, Norfolk District and the Virginia Institute of Marine Science examine oyster spat to see how well the baby oysters are doing on a sanctuary reef in the Great Wicomico River in Virginia.