Recent Progress: Increase

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 Goal Implementation Team (GIT) approved the Eastern Branch of the Elizabeth River in Virginia as a “bonus” tributary in 2020.

Scientists have developed restoration plans for all ten tributaries, but tributaries vary in their level of progress through the process of constructing and/or seeding reefs and then monitoring and evaluating the restored reefs. As of the end of 2024, eight of the ten originally selected tributaries have been restored (Harris Creek, Little Choptank River, Upper St. Mary’s River and the Tred Avon River in Maryland and the Lafayette, Piankatank, Lower York, and Great Wicomico rivers in Virginia), as well as the eleventh “bonus” tributary, the Eastern Branch of the Elizabeth River in Virginia. Restoration work is underway in the remaining two tributaries under this goal (the Manokin River in Maryland and the Lynnhaven River in Virginia).

Following reef construction and seeding, monitoring and evaluation will take place at three- and six-year intervals, continuing beyond 2025. These monitoring activities determine the overall success of the restoration activity by tracking success at recruiting new oysters, survival in the early stages after settlement or planting, natural mortality, disease status, growth, reproduction and shell accumulation. More information about monitoring and evaluation protocols, frequency and success metrics can be found in Restoration Goals, Quantitative Metrics and Assessment Protocols for Evaluating Success on Restored Oyster Reef Sanctuaries (PDF) from the Oyster Metrics Workgroup and from the 2024 Chesapeake Bay Oyster Restoration Update.

Outlook: On Course

The Oysters Outcome is on course and is expected to be met by the end of 2025, although monitoring and evaluation will continue past 2025. In fact, large-scale oyster restoration in Chesapeake Bay has become an internationally recognized success story. Scientists and resource managers from Europe, Asia and Australia have visited to learn about the effort, and National Oceanic and Atmospheric Administration (NOAA) staff have travelled nationally and internationally to describe the project.

Oyster Reef Restoration (2024) ^‍‍

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 (2024) ^‍‍

View on ArcGIS Online Map Viewer

Downloads:

‍Data (.xlsx) ‍Methods (.pdf)

According to the Maryland and Virginia Oyster Restoration Interagency Teams, partners have invested almost $115 million in oyster restoration in Chesapeake Bay tributaries to date. This investment only includes reef construction; costs such as benthic surveys to assess the health of the bottom of waterways, planning, permitting and monitoring are not reflected.

Oyster Reef Restoration Progress Dashboard

Download the Oyster Reef Restoration Progress Dashboard (.xlsx)
 

Maryland

According to the 2024 Chesapeake Bay Oyster Restoration Update, four out of five Maryland tributaries (Harris Creek and the Little Choptank, Upper St. Mary’s and Tred Avon rivers) in the Oysters Outcome have been restored. Restoration work in the Manokin River started in 2021.

• Harris Creek’s restoration work was completed in 2015 with a total of 343 acres of reefs restored, fulfilling the restoration plan. In 2017 and 2018, several reefs received a second planting of oyster larvae attached to shells, called spat-on-shell. As of 2021, all three- and six-year post-restoration monitoring is complete. Monitoring results show that the restored reefs are largely successful. For example, all 14 six-year-old reefs monitored in Harris Creek in winter 2020-21 met the Oyster Metrics (PDF) minimum threshold success criteria for oyster density and biomass, and 86% met the Oyster Metrics higher target criteria for these characteristics.
• The Little Choptank River’s restoration work was completed in 2020 with a total of 358 acres of reefs restored, as per its restoration plan. Monitoring showed that all of the six-year-old reefs met target density criteria, included oysters from multiple year classes and had sufficient shell substrate to persist into the future.
• The Tred Avon River’s restoration plan initially called for 147 acres of reefs to be present in the sanctuary, but this was later reduced to 130 acres. This work was completed in 2021. In the fall of 2021, monitoring showed that all of the six-year-old reefs met the minimum success criterion for oyster density, as well as the criteria for year classes and shell budget. Half of the reefs met the ideal target density criteria.
• The Upper St. Mary’s River’s restoration plan (PDF) called for 60 acres of restored reefs. Thirty-five acres of healthy, high-density oyster reefs already met those standards. Restoration work started in 2021. Hatchery-produced seed were added to 16 acres of reef (seed-only reefs) using spat-on-shell. Additionally, Maryland DNR constructed about nine acres of reefs from stone substrate that were seeded with spat-on-shell in 2022. The river is considered initially restored.
• The Manokin River’s restoration plan (PDF) calls for 441 acres of restored reefs. Restoration work started in 2021, and as of the end of 2024, 345 acres have been completed. The Manokin River Restoration Blueprint requires active restoration of the largest number of acres within any of the tributaries slated for restoration. Restoration work here will likely take through 2025 to complete.

Virginia

According to the 2024 Chesapeake Bay Oyster Restoration Update, four out of five Virginia tributaries (the Lafayette, Piankatank, Great Wicomico and Lower York rivers) in the Oysters Outcome have been restored. Restoration work is well underway in the Lynnhaven River.  

• The Lafayette River’s restoration plan (PDF) initially called for 80 acres of restored reefs. This was later revised to 82 acres. Seventy acres already met the definition of a restored reef due to existing restoration projects (22 acres) and historic reefs (48 acres). Nonprofit organizations finished the remaining restoration work in 2018, which made the Lafayette the first river in Virginia to be considered complete. Beyond the planned restoration work, in 2020, partners installed 405 oyster castles—instant habitats made of concrete, shell and limestone—and then seeded them with spat-on-shell. The tributary is now in the monitoring phase.  
• The Lynnhaven River’s restoration plan (PDF) calls for 152 acres of restored reefs. Of this total, 89 acres already met the definition of a restored reef due to the existing natural oyster population. As of the end of 2024, partners have restored 37 acres of reefs.
• The Piankatank River’s restoration plan (PDF) called for 440 acres of restored reefs. Of this total, 203 acres already met the definition of a restored reef. In 2023, restoration work was completed, surpassing the goal and reaching 497 acres of restored reefs.  
• The Lower York River’s restoration plan (PDF) called for 200 acres of restored reefs. Of this total, two acres already met the definition of a restored reef. By 2023, partners built an additional 202 acres, bringing the total acres of restored reefs to 204 and completing initial restoration.  
• The Great Wicomico River’s restoration plan (PDF) called for 124 acres of restored reefs. Of this total, 100 acres already met the definition of a restored reef. In 2021, partners worked collaboratively to restore the remaining 24 acres. 

In 2019, 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, brings the tributary’s total acres of oyster reefs to about 24. 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 Oyster Metrics success criteria.

Overharvesting, disease and habitat loss led to a severe drop in oyster populations over the last century. But healthy oyster reefs promote clean water, provide food and habitat, and in certain situations, protect shorelines from some wave erosion. 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 towards enhancing adaptability to changing environmental conditions.

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 December 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.

Ongoing

• Implementing and monitoring oyster reef restoration in select Maryland tributaries.
• Implementing and monitoring oyster reef restoration in select Virginia tributaries.
• Coordinating and communicating restoration decisions, planning and progress.
• Securing support and resources to ensure partners remain committed to the Ten Tributary initiative, including honoring funding commitments, full restoration implementation and monitoring.

Recently Completed

2023

• Completed initial in-water restoration of the lower York River.

2022

• Completed initial in-water restoration of the St. Mary's River.

2021

• Completed initial in-water restoration of the Great Wicomico, Piankatank, and Tred Avon rivers.
• Published NOAA Technical Memorandum (PDF) on research into ecosystem services provided by restored oyster reefs.

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