Ten Chesapeake Bay tributaries have been selected for oyster reef restoration: Harris Creek, the Little Choptank, Tred Avon, upper St. Mary’s and Manokin rivers in Maryland, and the Great Wicomico, Lafayette, Lower York, Lynnhaven and Piankatank rivers in Virginia. The Sustainable Fisheries GIT approved the Eastern Branch of the Elizabeth River in Virginia as an eleventh bonus tributary in 2020.

Each of these tributaries is at a different level of progress in a process that involves developing a tributary restoration plan, building and seeding reefs, and monitoring and evaluating restored reefs. As of 2020, three of the ten originally selected tributaries have been restored (Harris Creek and the Little Choptank River in Maryland and the Lafayette River in Virginia), in addition to the eleventh bonus tributary (the Eastern Branch of the Elizabeth River). Monitoring and evaluation will take place at three- and six-year intervals following construction and seeding. This monitoring and evaluation phase will not be complete until after 2025. More information about monitoring and evaluation protocols, frequency and success metrics can be found in a metrics report from the Oyster Metrics Workgroup.

Oyster Reef Restoration (2020) ^‍‍

Individual acreage targets are based on a tributary’s historic oyster habitat and currently restorable area.

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Oyster Restoration in Chesapeake Bay Tributaries (2020) ^‍‍

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According to the Maryland and Virginia Oyster Restoration Interagency Workgroups, partners have invested more than $65 million in oyster restoration in Chesapeake Bay tributaries over the past ten years. In late 2020, Virginia announced $10 million in new funding to support future oyster restoration in the Chesapeake Bay. This marks the first time that capital funds, which are typically reserved for infrastructure projects, have been explicitly designated to restore Virginia’s natural resources. The table below depicts the following information about the tributaries that have been selected for oyster restoration: where planning and restoration stand; the acres of reefs that have been restored toward established targets; and whether monitoring and evaluation is underway.

Oyster Reef Restoration Progress Dashboard

Download the Oyster Reef Restoration Progress Dashboard (.xlsx)

According to Maryland’s Oyster Restoration Update, 801 acres of oyster reef have been restored in Maryland waters as part of these large-scale restoration efforts. Two Maryland tributaries have been restored toward the ten tributaries outcome (Harris Creek and the Little Choptank River). Restoration work in the Tred Avon River is more than half complete, and restoration work in the upper St Mary’s and Manokin rivers is slated to start in 2021. In 2020, COVID-19-related restrictions reduced the University of Maryland’s Horn Point Oyster Hatchery’s seed production capacity through mid-June. Soon after, the facility increased production. The net result was that the number of oysters produced and planted onto sanctuary reefs in 2020 was reduced compared to typical years. Despite this, partners completed the initial restoration work in the Little Choptank River in 2020.

• Harris Creek’s restoration work was completed in 2015 and the tributary is now in the monitoring phase. The Harris Creek restoration plan originally called for 377 acres of reefs to be restored. The restoration target was later revised to 351 acres. Between 2012 and 2015, partners restored 351 acres of reefs. All three-year monitoring is complete, and work is focused on monitoring each reef as it turns six years old. Of the 43 six-year-old restored reefs monitored in Harris Creek at the end of 2019, 98% met the Oyster Metrics minimum threshold criteria for oyster density and biomass.
• Little Choptank River’s restoration work was completed in 2020 and the tributary is now in the monitoring phase. The Little Choptank River restoration plan originally called for 440 acres of reefs to be restored. Of this total, 45 acres already met the definition of a restored reef, by virtue of the existing healthy oyster reefs. Between 2014 and 2020, partners restored 358 acres of reefs, slightly more than in Harris Creek. This makes the Little Choptank effort the world’s largest oyster restoration project. Future work will focus on monitoring and, where needed, completing the scheduled second-year-class oyster seedings.
• The Tred Avon River restoration plan calls for 147 acres of reefs restored. As of 2020, more than 92 acres of reefs have been restored. The U.S. Army Corps of Engineers (USACE) plans to construct approximately 34 more acres of reefs followed by seeding in summer 2021. This will bring the acreage of restored reefs in the river to approximately 130 acres, which is more than the minimally restored threshold level of 125 acres.
• The upper St. Mary’s River restoration plan was finalized in March 2020 and calls for close to 60 acres of reefs to be restored. Thirty-five acres of healthy, high-density oyster reefs already exist, leaving approximately 25 acres to be restored. Approximately 16 acres in the river require only the addition of hatchery-produced seed oysters, which will likely be seeded in 2021. Maryland DNR has received a permit to build the nearly nine acres of reefs that require a substrate base and is in the process of hiring a subcontractor for reef construction. In-water construction is anticipated to start in 2021, with seeding in 2021 or 2022.
• The Manokin River restoration plan was finalized in July 2020 and calls for 441 acres of reefs to be restored. This would eclipse the Little Choptank River as the largest oyster restoration project in the world. An estimated 20 acres of healthy, high-density oyster reefs already exist, leaving approximately 421 acres to be restored. These 441 acres of reefs are currently undergoing additional prerestoration surveys, which may reveal that some of these areas do not require restoration. This would reduce the number of acres projected to need restoration. Maryland DNR has received a permit to build reefs with substrate in the river and is in the process of conducting public outreach and hiring a subcontractor for reef construction. In-water reef construction and seeding are anticipated to start in 2021.

According to Virginia’s Oyster Restoration Update, one Virginia tributary of the original five selected tributaries, the Lafayette River, has been restored toward the ten tributaries outcome. Overall, 294 acres of oyster reef have been restored in the large-scale effort across five tributaries. Restoration plans have been finalized for all five tributaries toward the outcome, including the Great Wicomico River in 2020. Despite delays due to COVID-19 restrictions, partners were able to construct more than 74 acres of reefs in Virginia in 2020.

• Lafayette River’s restoration work was completed in 2018 and the tributary is now in the monitoring phase, making it the first river in Virginia to be considered complete under the ten tributaries outcome. The Lafayette River’s restoration plan called for 80 acres of reefs to be restored. Of the 80 acres, 70 acres already met the definition of a restored reef due to older existing restoration projects (22 acres) and historic reefs (48 acres). Going above and beyond the planned restoration work, in 2020, partners installed 405 oyster castles and then seeded them with spat-on-shell.
• The Lynnhaven River restoration plan calls for 152 acres of reefs to be restored. Of this total, 89 acres already met the definition of a restored reef, by virtue of the existing natural oyster population. Partners have constructed an additional 16 acres of reef and installed 136 reef balls and 860 oyster castles. Partners plan to restore a minimum of 41 acres in 2021.
• The Piankatank River restoration plan calls for 438 acres of reefs to be restored. Of this total, 203 acres already met the definition of a restored reef while partners have built an additional 175 acres of reefs, bringing the total to 378 restored acres. In 2021, partners plan to construct a minimum of 33 acres of reefs.
• The lower York River restoration plan calls for 200 acres of reefs to be restored. Of this total, 2 acres already met the definition of a restored reef, by virtue of the existing natural oyster population. Partners built an additional 33 acres in 2019 and 13 acres in 2020, bringing the total to 48 restored acres.
• The Great Wicomico River restoration plan calls for 122 acres of reefs to be restored. Past work by partners has resulted in 100 acres of oyster reefs that meet the definition of a restored reef. Partners intend to work collaboratively to restore the remaining 22 acres.

In 2020, Virginia selected a bonus tributary for restoration, the Eastern Branch of the Elizabeth River. In 2020, partners constructed 21 acres of reefs in the Eastern Branch which, when added to previously restored acres, results in the construction of nearly 24 acres of oyster reefs. The Elizabeth River’s Eastern Branch oyster population is considered fully restored. Monitoring will take place at three and six years after construction to assess whether the restored reefs meet the success criteria established in the Oyster Metrics.

Overharvesting, disease and habitat loss have led to a severe drop in oyster populations over the last century. Oyster restoration at the tributary level aims to increase oyster populations to provide the ecosystem services that oyster reefs perform.

Tracking our progress toward restoring oyster reefs is critical to understanding our progress toward enhancing climate resiliency. Oyster reefs promote clean water, provide food and habitat to species threatened by climate change, and protect shorelines from strong waves. The latter mitigates the impacts of coastal floods and reduces the extent of property damage caused by storm events. For these reasons, oyster reefs help us prepare for some of the disruptions that climate change can cause.

Learn About Factors Influencing Progress

To achieve this outcome, Chesapeake Bay Program partners have committed to:

• Planning and implementing oyster reef restoration in select Maryland and Virginia tributaries.
• Coordinating and communicating our progress toward and research related to oyster reef restoration.

Monitoring and assessing progress toward the outcome will occur at the reef, tributary and Chesapeake Bay-wide levels. Reef- and tributary-level monitoring will take place at three and six years after restoration is complete to determine if a tributary has been successfully restored according to agreed-upon metrics.

As part of the Chesapeake Bay Program’s partnership-wide implementation of adaptive management, progress toward this outcome was reviewed and discussed by the Management Board in November of 2021. It will be reviewed and discussed by the Management Board again in November 2023.

Download Management Strategy (.pdf)

Chesapeake Bay Program partners have committed to taking a series of specific actions that will support the management approaches listed above.

Completed actions from this outcome's Logic & Action Plan include:

• In 2019, the Sustainable Fisheries Goal Implementation Team (GIT) approved the selection of Manokin River as the tenth tributary chosen for oyster reef restoration. The Maryland Interagency Oyster Team and Maryland Department of Natural Resources recommended Manokin River as suitable for large-scale oyster restoration.

Learn About Logic & Action Plan

The Sustainable Fisheries Goal Implementation Team leads the effort to achieve this outcome. It works in partnership with the Vital Habitats, Water Quality and Healthy Watersheds goal implementation teams.

Participating partners include:

• Maryland Department of Natural Resources (State of Maryland)
• Virginia Marine Resources Commission (Commonwealth of Virginia)
• City of Norfolk
• City of Virginia Beach
• Christopher Newport University
• Virginia Commonwealth University
• Virginia Institute of Marine Science
• University of Maryland Center for Environmental Science
• Potomac River Fisheries Commission
• Chesapeake Bay Commission
• National Marine Fisheries Service (National Oceanic and Atmospheric Administration)
• U.S. Army Corps of Engineers
• U.S. Fish and Wildlife Service
• Chesapeake Bay Foundation
• Elizabeth River Project
• Lynnhaven River NOW
• The Nature Conservancy
• Oyster Recovery Partnership
• Oyster Reefkeepers
• Pleasure House Oysters