In Praise of the Humble Oysters

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Chesapeake Heroes: An article series examining local organizations and citizens working toward a healthier environment. 

Public-private partnerships utilize large-scale projects, innovative strategies, and community involvement to restore Maryland’s oyster population. 

When Maryland committed to restoring the oyster populations in five tributaries in the state’s portion of the Chesapeake Bay by 2025 as part of the Chesapeake Bay Program’s 2014 Chesapeake Bay Watershed Agreement, the organizations involved in this monumental effort realized that the project would be a tremendous undertaking…and the outcome uncertain. The tributaries targeted for restoration included Harris Creek, the Little Choptank River, the Tred Avon River, the Upper St. Mary’s River, and the Manokin River. (The agreement also called for the restoration of five tributaries in Virginia.) 

But the scale of the project didn’t discourage the oyster restoration partners. Instead, they embraced the challenge—harnessing their collective expertise and focusing on their mission. Ten years later, Maryland is on target to meet its goal. To date, restoration work in four of the five tributaries is complete. Restoration of the Manokin River is anticipated to be completed by 2025.

“The five-tributary strategy was definitely a lofty goal,” says Paul Schurick, director of partnerships for Oyster Recovery Partnership (ORP), a nonprofit organization that strives to lead the restoration of the native oyster population in the Chesapeake Bay. “Restoration on this scale had never been undertaken. But we now know it’s possible. 

“When the work in Harris Creek was completed, I remember that everyone seemed to agree that the goal was, in fact, wholly achievable. We had just restored 343 acres in Harris Creek—the largest man-made reef at the time—so the others suddenly seemed within reach. The Little Choptank, at 351 acres, was next. The Manokin, when finished, will top them all at 441 acres. There is no doubt that our partnership is capable of sustaining restoration at this scale.” 

Indeed, oyster restoration efforts continue to show signs of significant progress. More than 1.7 billion new juvenile oysters were planted on sanctuary and public oyster fishery sites in Maryland’s portion of the Chesapeake Bay in 2023 alone, setting a new annual record and further underscoring Maryland’s commitment to large-scale oyster restoration. (To put this number in perspective, 501 million oysters were planted in 2014, according to data from ORP.) The 2023 record sets a milestone, bringing the total number of oysters planted since the launch of the Chesapeake Bay Watershed Agreement’s large-scale oyster restoration strategy in 2014 to almost 7 billion. 

“Planting 1.7 billion oysters (sic) this year shows the success of the broad partnership of watermen, scientists, academics, nonprofits, and state and federal government officials dedicated to this vital natural resource and economic driver for Maryland,” said Governor Wes Moore. 

Most of the oysters for the five tributaries are grown at University of Maryland Center for Environmental Science (UMCES) Horn Point Laboratory in Cambridge. One of the largest oyster hatcheries on the East Coast, the Horn Point Oyster Hatchery, located on the Horn Point Laboratory campus, produces oyster larvae for use in research, restoration, and education.

Large-scale oyster restoration is completed through the hard work and dedication of a dynamic partnership of organizations, including ORP, the Maryland Department of Natural Resources (DNR), UMCES Horn Point Laboratory, the National Oceanic and Atmospheric Administration (NOAA), the U.S. Army Corps of Engineers, and the Maryland Watermen’s Association as well as numerous other partners.

“Our scientists have been working hard to optimize the production of oysters at our Horn Point Hatchery, and it’s paying off,” says University of Maryland Center for Environmental Science Interim President Bill Dennison. “Working with our partners in this effort, combined with good weather and good water quality, this record level of oyster production is being realized.” 

In addition to setting a new annual record for oyster planting, oyster restoration reached another milestone in 2023. According to ORP, oyster restoration was officially recognized by the EPA as a Best Management Practice (BMP) due to oysters’ ability to improve water quality in the Bay by removing harmful nutrients. 

Jump-Starting Mother Nature

Oysters play a vital role in the ecosystem and help improve the health of the Bay. They filter excess nutrients and pollutants from the water, and they grow in reefs that provide habitat, food, and protection for other marine organisms. And, of course, annual oyster harvests and aquaculture boost Maryland’s commercial seafood industry, which bolsters the regional economy. However, due to factors such as historic overharvesting and, more recently, pollution and disease, the oyster population declined dramatically over the decades.

Oysters spawn in the summer when water temperatures rise. Adults release eggs and sperm into the water, and fertilized eggs develop into free-swimming larvae. The larvae are carried by the Bay’s currents for several weeks and then settle to the bottom of the Bay and attach to a hard surface, or substrate. Once they attach to a substrate, they are called spat. 

“Environmental factors, including favorable weather conditions, good water quality, and higher salinity levels, as well as natural events, such as low disease-related mortality and good reproduction, lead to an increase in the oyster population,” Schurick says. “However, since these factors are unpredictable and vary from year to year, oyster restoration is a critical strategy that can help jump-start Mother Nature.”

A complex process, oyster restoration partners identify sites that are suitable for accepting oysters. Since oysters require substrate to survive, ideal areas are those least affected by silt and sediment. Once a site is selected, it’s prepared to receive hatchery-produced spat-on-shell, which is then transported to the newly prepared reef and washed overboard, where it’s allowed to grow. Once the oysters are deposited onto the reef, scientists monitor the site and its progress. 

The importance of substrate in the restoration process cannot be overemphasized. Oyster shell is the best natural material used to rebuild oyster reefs, but it’s in short supply. In response to Maryland’s lack of oyster shell, Governor Wes Moore created the Oyster Shell and Substrate Taskforce under an executive order in 2023. 

“Substrate is crucial for oysters as it provides habitat for oyster larvae to attach to and become spat,” says Chris Judy, director of the DNR’s shellfish division. “Spatset is diminished if suitable substrate is lacking, and the oyster population suffers. The Oyster Shell and Substrate Taskforce is exploring ways to increase shell and other materials that are needed to improve Maryland’s oyster population. This includes identifying ways to retain and increase shell and substrate, evaluating ways to meet the demand from the public fishery, aquaculture industry, and restoration [component] currently and in the future, and evaluating the economics of substrate.” 

The scope of oyster restoration is immense, and many organizations play a role in this critical effort. In addition to large-scale projects completed by the major restoration partners, other key organizations offer programs that also help jump-start Mother Nature. Although they operate on a smaller scale, their contributions to oyster restoration are invaluable.

Growing Oysters 

Launched by the DNR in 2008 in the Tred Avon River, Marylanders Grow Oysters (MGO) is a popular program that offers waterfront homeowners the opportunity to volunteer to grow oysters in cages suspended from their piers. Participants care for the oysters for about nine months (September to late May/early June) until it’s time for them to be planted in local oyster sanctuaries. MGO, which is managed by the DNR in conjunction with ORP and local organizations, now is active in more than 30 rivers, tributaries, and creeks. Participants work with their local program coordinator.

To be eligible, participants must have a pier with at least four feet of water at the lowest tide and at least 5 ppt (parts per thousand) salinity. The cages are attached to the pier with rope, so they hang at least six inches from the bottom—away from the soft mud and in the water currents, which bring them food—and far enough below the water’s surface to avoid exposure to freezing air during the winter. Maintenance requires rinsing the oysters every two weeks by dunking the cages in the water to remove silt or sediment buildup. 

According to Tommy Price, operations manager of Shell Recycling Alliance/Marylanders Grow Oysters for ORP, 40 deliveries of cages were made during late August into early October 2023 to 33 tributaries of Maryland’s portion of the Chesapeake Bay and Maryland Coastal Bays. This includes 19 community groups and Riverkeeper organizations (some of which are subdivided into smaller creek groups/neighborhoods). Approximately 2,000 participants cared for nearly 6,000 cages in 2023, and about 4–4.5 million spat were produced. At the time of writing, the oysters are slated to be planted during the end of May through June 2024. 

“MGO is the best way for folks to get a hands-on understanding of how oysters live and grow as well as what goes into the broader restoration industry,” Price says. “MGO oysters make up less than 1 percent of ORP’s total spat-on-shell oyster plantings, but it’s without a doubt the best way to get communities involved in putting oysters into their local waterways.”

The Severn River Association (SRA), a conservation organization based in Annapolis, operates the largest MGO program in the state with 304 growers and 2,000 cages. Ben Fertig, Ph.D., restoration manager of SRA, administers the program, and creek captains work with growers.

“MGO is both a restoration program and an educational program,” says Jesse Iliff, executive director of SRA. “No specialized training is required, and it doesn’t involve a major time commitment. MGO is also a great conversation piece. Visitors to your home might see the ropes hanging in the water by your pier and ask about them, which opens up a great opportunity to talk about the program. And, of course, MGO is a lot of fun—a hands-on experience that allows growers to engage with marine organisms.” 

ShoreRivers’ MGO program consists of 100 growers who care for 400 cages of oysters. A nonprofit organization based in Easton that protects and restores Eastern Shore waterways, ShoreRivers serves the Chester, Choptank, Sassafras, Miles, and Wye rivers and Eastern Bay. 

“People really enjoy the program,” says Laura Wood, agriculture and restoration coordinator for ShoreRivers. “It offers a glimpse of an ecosystem within a cage, and it’s a great learning experience. When it’s time to plant the oysters in the local sanctuaries, ShoreRivers is available to ferry the oysters out to the sanctuary reefs, but many growers who have boats choose to do this themselves. It connects them with their river and brings the MGO experience full circle.”

Both SRA and ShoreRivers have partnered with the Smithsonian Environmental Research Center (SERC), which takes video footage underwater once the oysters have been planted, allowing participants to see the reefs. 

Members of the community who aren’t waterfront homeowners may be able to participate in MGO by coordinating with a local marina or community pier. To learn more about MGO, visit www.dnr.maryland.gov/fisheries/pages/MGO/index.aspx.

Building Reef Balls

The Living Reef Action Campaign (LRAC), a program offered by Coastal Conservation Association Maryland (CCA Maryland), a nonprofit organization that advises and educates the public on the conservation of marine resources, provides in-class and hands-on learning experiences in area schools to teach students about the ecological benefits of oysters and the importance of habitat creation and restoration. 

Students build artificial reef components made of concrete (called reef balls), which are deployed in the Chesapeake Bay and its tributaries, where they create new three-dimensional reef structures. Deployment sites are carefully selected and approved as artificial reef sites. Established in 2015 by CCA Maryland’s Central Region Chapter in Carroll County, LRAC is not only fun, but it also helps generate interest in the environment and foster stewardship.

In some cases, hatchery spat are attached to the reef balls before being deployed to give them a guaranteed population of oysters. However, CCA Maryland’s goal is to deploy them without spat in areas with high oyster populations. Since the organization may use spat from hatcheries, there are multiple demands on the supply chain. Although CCA Maryland attaches spat to the reef balls when possible, the nonprofit is happy to let Mother Nature do the work once they are in the water.

“The Living Reef Action Campaign is one more way to get the community to roll up their sleeves and get involved,” says David Sikorski, executive director of CCA Maryland. “It’s a great opportunity to bring oyster restoration to the forefront and learn more about the regional ecosystem. Our efforts make a difference, and we hope to continue to see measurable growth in the output of oyster reefs.”

LRAC, which operates from a pair of trailers that travel throughout the region for reef ball building activities, has made a positive impact—not only in schools but also in the community. The first reef ball was deployed off Tilghman Island in 2016. To date, nearly 2,000 reef balls have been deployed by CCA Maryland and its partners. In 2024, 300 reef balls are slated to be deployed in St. Mary’s River Oyster Sanctuary and 175 in the Magothy River at Noah’s Reef.

Although LRAC launched in the local school systems, CCA Maryland welcomes opportunities to work with community organizations, volunteers, and businesses. For more information and to learn about participating in a reef ball build day, visit www.ccamd.org.

Recycling Oyster Shell

In addition to getting involved in MGO or LRAC, members of the community can support the restoration effort by recycling oyster shells. Created in 2010, ORP’s Shell Recycling Alliance (SRA) collects shells from restaurants that meet certain criteria. These shells, which would otherwise be thrown in the trash, are recycled, cleaned, treated with spat, and put back into the Bay. Since its inception, SRA has recycled 320,000 bushels of shell. 

Recycling shells when dining at qualifying restaurants or buying local oysters and dropping the shells off at public drop sites are easy ways to support this cause. For a list of recycling collection stations or restaurants that recycle shells, visit www.oysterrecovery.org.

“Shell is the key to oyster production, so recycling shells is critical to our work,” Price says. “With each recycled shell, ORP and its partners can produce and plant up to 10 spat-on-shell oysters. Making sure shell stays out of the landfill and returns to our waterways is a win-win for the environment.”

Oyster restoration takes various forms. Whether completing a large-scale restoration project, growing oysters in cages, building reef balls, or recycling oyster shells, everyone can make an impact. From major restoration partners to smaller organizations to members of the community, Maryland is committed to its mission of restoring the oyster population and ensuring a cleaner Bay—now and for the next generation.

“Oyster restoration has scaled up, and the picture looks much different now than it did 10 years ago,” Schurick says. “The movement has grown significantly, and we know our capabilities. It’s critical that we stay the course. We can’t lose the progress we have worked so hard to achieve.”