Restoration Projects: Oyster Reefs

Patapsco River Oyster Reef Restoration

Seven partners from Maryland’s academic, corporate, and environmental communities created an educational oyster reef that restored a portion of the historic oyster distribution in the upper Chesapeake Bay, and will serve as an outreach, education, awareness, and research site. The concept for the project was to provide the seed money for expansion of the aquatic reef substrate and initial planting, and to serve as a catalyst for a focused, centralized site for oyster replenishment activities and on-site environmental education, formed to use the common goals, interests, and expertise of each partner. The project and reef creation funded by this grant: 1) allows additional placement of future years’ oyster production, and 2) provides educational opportunities for years to come as a dynamic and functioning aquatic reef habitat.

In the upper Bay, extensive development, shoreline alteration, and increases in sediment loads have caused much of the historical oyster populations to vanish. Further, much of the ecologically valuable hard-bottom substrate has been either removed or silted over. Two sites of historical significance near the urban center of the upper Bay, Fort Carroll and Fort McHenry, initially were sited on or around oyster bars due to the hard bottom it provided. While the sites likely represent the upper extent within the Bay (the lower limit in terms of salinity) for oysters to survive and grow, their proximity to Baltimore and thousands of upper Bay and inner-city students is ideally situated to serve as a readily accessible site for environmental education and awareness programs.

Young oysters, known as spat, are placed in nursery sites and grown out in bags until about 15 to 20mm in size, often 10 to 15 spat per shell.

Oyster larvae produced at the Horn Point Oyster Hatchery were set on 300 bushels of oyster shell (600 shell bags). Students and teachers received materials and instructions for building the floating cages, and guidelines for maintaining the cages and monitoring the oysters. The oyster-growing work began in September and continued for ten months. At the end of the academic year, the oysters grown in floating cages by the students were planted on the reef at Fort Carroll. Shell planting was accomplished in early summer 2000. Shell will be dredged, transported, and placed on site by a local marine contractor. Approximately 60,000 bushels of shell were deposited on site. The shell planting covers about 3 acres, planted on average eight inches thick on the bottom. Site-specific characteristics, including areas of harder or softer bottom than anticipated, can alter how thick the shell is planted in certain areas, resulting in slightly larger or smaller aerial coverage. Some mounding of shell occurs in areas to increase three-dimensional character of the site, and to allow for subplots for experimental plantings.

During regularly scheduled field trips, school groups attending the site with both the Chesapeake Bay Foundation and Living Classrooms Foundation dredge subsamples of the reef to monitor the reef for oyster survival, growth, and the establishment of a commensal reef community. Water-quality profiling is conducted during each site visit. This information will be used to provide comparisons between oysters initially grown on- and off-bottom, as well as with the oysters placed at the Fort McHenry site.

The anticipated outcome, from a restoration perspective, is that the reef site will recolonize itself from regular yearly plantings of young oysters over the next five years, and then maintain itself as a functioning restored habitat within the upper Bay ecosystem. Since the site is both relatively isolated and held under a private lease to Living Classrooms Foundation, the restored habitat created through this project will essentially become an oyster "sanctuary" in the Upper Bay.

More importantly, the oyster reef at Fort Carroll—and potentially at Fort McHenry in the future—can serve as living gauges to monitor water-quality conditions in a highly urbanized section of the Bay, both through its ultimate success, and indirectly as an outreach and awareness vehicle for the many school and citizen programs that will become involved in it. From an educational perspective, the project will result in an organized collaborative education partnership that can be transferred to other Bay restoration and environmental education sites and activities in the future.

Elizabeth River Oyster Reef Restoration

This project reseeded (restored) about one acre of oyster reef in the West Branch of the Elizabeth River, Virginia, restoring the habitat value, filter-feeding capability, and the reproductive potential the reef community would provide. Additionally, the activity provided an opportunity for local middle-school students to become actively engaged in a resource restoration project in their home waters. The project stimulated public awareness of the ecological value of oyster reefs while instilling a sense of community stewardship in local restoration work. The project succeeded because of the development of a partnership approach to oyster restoration between a local community, a conservation organization, a state agency, and NOAA. The project featured a partnership among the Virginia Marine Resources Commission, Chesapeake Bay Foundation, civic organizations, and private citizens to stimulate public awareness of the ecological value of oyster reefs and a sense of community stewardship in local restoration work.

A tug moves a bargeload of shell into position over the proposed reef restoration site.


A powerful hose is used to wash the shell off the barge into the desired mound shape.

The reconstruction of the reef in the Western Branch facilitates an ongoing community-based effort to improve oyster reef habitat in local waters. In subsequent years, additional oysters will be grown in cages by area students for transplanting onto the reef. Students will help monitor the growth and survival of oysters transplanted to the restored reef as well as the development of the reef community over time through field trips. The reef probably will also receive oysters grown by civic organizations and private citizens.

This project has both educational and ecological benefits, and has served as a model for establishing partnerships between communities, conservation organizations, and state and federal government agencies for achieving environmental restoration in the area. Students learned not only about the biology of oysters and their associated reef communities, but also about the factors affecting the overall health of their local waterways. Students also had the opportunity to apply concepts in science and math to a real-world problem and had the experience of being directly involved in the restoration effort. The placement of oysters onto the constructed reef has had ecological benefits as well, as noted by the initial spatfall survey, which recorded oyster spat densities in the range of 100 per meter.

The project was initiated in the summer of 1987, with the goal of providing hatchery-produced seed oysters to nine Hampton Roads middle and high-school students, along with appropriate equipment and educational materials to allow them to grow the oysters for 10 months. At the end of the academic year, the oysters were placed on a reconstructed oyster reef in the Western Branch. The reef was reconstructed through the purchase and placement of 32,000 bushels of shell.

Teachers and students inspect the young oysters grown during the academic year by numerous school groups. These young oysters are then placed on the restored reef to "jumpstart" the restoration of live oysters.

Lafayette River Oyster Reef Restoration

NOAA and FishAmerica Foundation joined with the Virginia Marine Resources Commission (VMRC) and the Rotary Club of Norfolk to continue oyster reef habitat restoration in the heart of the City of Norfolk, where surveys reveal that remnant oyster populations still exist in the Lafayette River. Oyster shells were purchased and transported by barge, and deployed into a reef structure. Through a program coordinated by the Chesapeake Bay Foundation, hatchery-produced seed oysters were grown by middle and high school students in floating cages throughout the River.

A crane places buckets full of shell into the water to create the mounded reef formation.

Students and teachers were provided materials and instructions for building the floating cages and guidelines for maintaining the cages and monitoring the oysters. They oyster-growing work took place over an academic year, at the end of which the oysters were planted on the reconstructed reef. Students will help monitor the growth and survival of the transplanted oysters as well as the development of the reef community over time through field trips. The reefs likely will also receive oysters grown by civic organizations and private citizens organized through the Chesapeake Bay Foundation and Restore the Oyster (a citizen-based cooperative) in coordination with VMRC, for a restoration project worth $53,000.

The recently constructed reef has already been marked to alert boaters. The top of the reef extends just above the water line at low tide.

New Restoration Projects: Patuxent, Yeocomico, and Elizabeth Rivers

Continuing a plan that has worked successfully in a number of Chesapeake Bay tributaries, NOAA and National Fish and Wildlife Foundation funds were partnered to provide oyster reef restoration activities in three Bay tributaries.

In the Yeocomico and Elizabeth Rivers in Virginia, the Virginia Marine Resources Commission partnered with the Chesapeake Bay Foundation and other concerned nonprofit organizations to create additional reef broodstock sanctuaries. These reefs, in conjunction with shell plantings, were placed around the restored three-dimensional broodstock sites, and serve an outreach/education component with the school groups involved, and further the restoration goals within each river.

In Maryland, the Chesapeake Bay Foundation partnered with the Maryland Department of Natural Resources to utilize a newly designated sanctuary site within the Patuxent River seeded with young oysters grown in their ongoing citizen oyster gardening program.

Each project serves as a catalyst for oyster and Bay environmental education, formed to draw on the common goals, interests, and expertise of each partner.

	Virginia reefs will have the typical mounded, intertidal reef structure.
	In all three projects, restored reefs will be seeded with oysters grown by school groups or citizen volunteer oyster gardeners.

Maryland Oyster Restoration Activities Award

This project is as a result of a grant designated for "Chesapeake Bay Oyster Research Activities," supported by Senator Mikulski (D-Maryland). Funds go toward oyster restoration activities, and these oysters should subsequently be available for harvest. The activity also was the first large-scale field test of a potentially disease-resistant strain of the eastern oyster. This restoration/field test will provide information that may play a role in overcoming existing effects of disease and allow more oyster stocks to recover to some degree of their historical levels.

The Oyster Recovery Partnership (ORP) is a nonprofit coventure of watermen, aquaculturists and environmentalists dedicated to the restoration of oyster resources in Chesapeake Bay. The partnership was formed as a result of the Oyster Roundtable convened by the State of Maryland in 1993 to address major concerns about how to restore oyster stocks. ORP helps to oversee, coordinate, and monitor the oyster activities set forth in the Roundtable agreement that resulted. Since its start-up in 1994, ORP has either directly planted or helped with the planting of more than 35 million hatchery-produced baby oysters using volunteer labor.

The intended river for year-one restoration activity (pending final site selection and planning) is the Choptank, and includes one site in Tangier Sound. Oyster shell dredged from a site in the upper Bay was placed on historic hard bottom. These shelled areas subsequently were planted with young oyster "spat," which are baby oysters set on bags of oyster shell and reared in a hatchery or nursery setting until they are about 1/4" to 1/2" in size. The effort involved a tremendous labor commitment by all parties involved, and featured a significant volunteer component as well. The sites will be monitored in subsequent years to assess growth, mortality, onset of disease, and natural reproduction of these oysters after they grow larger. The sites that are being restored should be available to some method and level of harvesting in four to six years.

The sites chosen were decimated primarily by historical physical harvesting activity, which flattened out reefs that were elevated off of the bottom into the water column, followed by increased sedimentation from human activity and land development, and most recently by the onset of two oyster diseases.

The goal of the award is to restore oyster reef habitat, increase the numbers of oysters available to watermen for harvest, restore the Bay’s oyster stocks to be self-sustaining, and test a potential countermeasure to existing disease pressure.

The oyster is extremely important—economically and ecologically—to the Chesapeake Bay. Oyster harvesting has been an integral part of the Bay region’s economic development and cultural heritage. The filtering capabilities of the oyster enable it to remove large quantities of plankton and sediment from the water column, while its shells provide habitat for a wide variety of benthic organisms and fish species. Many scientists feel that the restoration of the oyster is the key to improving water quality and the overall health of the Bay.

	Oyster shell is used in the hatchery to provide a substrate for larval oysters to settle on.
	Young oysters ready for planting are removed from the bags and either manually placed on the reef, or washed off the deck of large boats onto the reefs with a water cannon, usually about 1 to 2 million per acre.