Bringing Back an Icon

World's Largest Oyster Restoration Project - Complete!

Harris Creek restoration partners toss oysters overboard as part of the final oyster planting in the tributary.

September 15, 2015 marked a major milestone in the life of the Chesapeake Bay - the completion of the largest oyster restoration project on the planet.

It's part of an aggressive and concerted effort to restore oyster reefs in 10 Chesapeake Bay tributaries by 2025. And we’re just getting started.

Will you help us continue this work?

Oysters are an iconic species in the Chesapeake Bay. They filter sediment and algae and absorb nitrogen from the water, while providing important nurseries and feeding grounds to rockfish, crabs and other marine life.

For generations, oysters have also played an important role in the bay economy as a food that locals and tourists love.

In fact, it’s possible they have been loved to death.

Overharvest, pollution and disease have decimated populations and left remaining oysters unable to fill their ecological and economic roles.

Bringing Back an Icon

Fortunately, recent and dramatic changes in the public policy arena, coupled with emerging scientific understanding and the creation of large-scale oyster sanctuaries, are providing a clear path forward to restore this keystone species.

On the Chesapeake Bay tributary of Harris Creek in Maryland, representatives from The Nature Conservancy gathered with partners from NOAA, the Army Corps of Engineers, the state of Maryland, the Oyster Recovery Partnership, U.S. congressional and state representatives, and others to celebrate the completion of the initial construction and seeding phase of a project that started more than five years ago.

At 350 acres, the Harris Creek reef is bigger than the National Mall and has been seeded with more than 2 billion oysters. These oysters were bred at the University of Maryland's Horn Point Hatchery, where they were selected for their resistance to dermo (Perkinsus marinus) and MSX (Haplosporidium nelson), two diseases that have decimated oyster populations over the last 60 years.

Harris Creek’s reefs are providing new homes for fish and crabs and creating cleaner water. It's an example of how we can bring back an icon of the Chesapeake Bayboth here and beyond.

Measuring Success

The 2016 Oyster Reef Monitoring Report released by NOAA on July 17, 2017, indicates that oyster reefs restored in Harris Creek in 2013 are highly successful. Data and analysis show that 97% of those reefs met the requirements for oyster density (at least 15 oysters per square meter) and biomass when they were monitored in 2016.

The 30 oyster reefs studied, totaling 90 acres, were constructed in Harris Creek in 2013.  Following the plan for the Harris Creek restoration, each restored reef will be monitored at three years, and again at six years, after restoration. A report released last year noted that 100% of the 12 reefs covering 102 acres where initial restoration was completed in 2012 met oyster density and biomass success criteria.

Read the full 2016 monitoring report here.

What's Next

While ground-breaking in its own right, the Harris Creek project also provides a road map for large-scale oyster restoration efforts in other Chesapeake Bay tributaries, including Maryland's Tred Avon and Little Choptank rivers. 

In Virginia’s Piankatank River, two sanctuary reefs totaling 25 acres were constructed in 2014 and 2015, with an additional 25 acres of reef completed in May, 2017.  Summer 2018 will see another 10 acres of reef built, moving us closer to a goal of 428 acres of oyster restoration in the Piankatank by 2025.

Because disease conditions change from year to year throughout the bay, partners will also monitor Harris Creek’s oysters to understand the prevalence of pathogens and the impact on oyster populations.

The map below, created by Elizabeth North from the University of Maryland Center for Environmental Sciences, shows a model for how oyster larvae are transported throughout Harris Creek. 

By restoring and repopulating large oyster reefs in key parts of the bay, we hope to reach a tipping point where oyster populations become sustainable, expanding their numbers and the benefits they and their reefs provide.


2016 Oyster Reef Monitoring Report Released (NOAA - July 17, 2017). The 2016 Oyster Reef Monitoring Report indicates that oyster reefs restored in Harris Creek in 2013 are highly successful.

New Report Finds Ample Oyster Growth on Restored Eastern Shore Reefs (The Chesapeake Bay Journal - July 27, 2016).  A new report says large-scale restoration work completed on a nearby Eastern Shore waterway is doing well so far.  The report concludes that a dozen restored oyster reefs checked last fall in Harris Creek show "healthy restoration".

Man-Made Oyster Reefs in Choptank Creek Meeting Benchmarks, NOAA Report Finds (The Baltimore Sun - July 27, 2016).  As a Maryland panel prepares to decide whether to restart a stalled oyster restoration project, a similar effort in another Choptank River tributary is meeting early goals, a survey has found.


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