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

A report released by NOAA on July 27, 2016 concluded that Harris Creek shows "healthy restoration".

The agency surveyed a dozen oyster reefs in Harris Creek covering 102 acres.  Half of these reefs were found to have 50 or more oysters per square meter - the restoration effort goal.  The survey was conducted in fall 2015, three years post restoration. 

Sampling also found varying sized oysters, indicating multiple generations of animals growing on the reefs and a sign that the reefs had attracted natural reproduction. 

Read the full report here.

What's Next

Over the next two years, The Nature Conservancy and partners will help measure how much pollution this restoration is removing and how many more fish are growing.  NOAA will also continue to monitor oyster densities at regular intervals.

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 have been constructed and up to 50 acres of new oyster sanctuary reef will be built in 2016 to help reach the restoration goal for the river. 

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.


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.

Scientists Say Maryland's Gigantic New Oyster Reef is a Pearl that Could Save the Chesapeake Bay (The Washington Post - September 23, 2015). Maryland can lay claim to the world’s largest man-made oyster reef. It was finished just days ago, and rests at the watery bottom of Harris Creek on the Eastern Shore, spread across more acres than the national Mall.

A Final Oyster Planting in Harris Creek (The Star Democrat - September 15, 2015). Tuesday, Sept. 15, was the last oyster spat planting in Harris Creek, wrapping up what the Nature Conservancy calls the largest oyster restoration project in the world.


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