Flipping the cages on sustainable aquaculture: a study on oyster aquaculture technique and policy to reduce pathogens

Project Update March 2024:

The S.C. Sea Grant Consortium (Consortium) hosted a kickoff meeting in April 2023 including the research team from the South Carolina Department of Natural Resources (SCDNR), participating shellfish farmers, and the South Carolina Department of Health and Environmental Control (SCDHEC). Principal Investigator Pedigo engaged a wide variety of experts during year 1 of the project in addition to the project team including those who have conducted similar oyster cage resubmergence focused studies in other states, and engaging the Food and Drug Administration (FDA) lab in Dauphin Island, AL well in advance to set up logistics for shipping samples in years 2 and 3 of the project. A Vibrio Assistance Review Board (VARB) request to FDA was submitted by SCDHEC on behalf of this project in August 2023. The project team submitted clarifying comments to FDA in September 2023 and January 2024.

All participating farmers have set aside stocked oyster cages for the study, with the oysters growing to market size throughout year 1 of the project. These oysters will then be ready to be sampled in summer 2024. Regular project team meetings were held throughout year 1 to refine the sampling, temperature control, and shipping protocols; and to establish field logistics. Three field teams have been established in order to sample from all three farms on the same day. A practice trial with all the field teams at a Lowcountry Oyster Co. lease site was held in February 2024 to get a better feel for the field logistics. 

Project Update March 2025:

VARB approval from FDA was obtained in June 2024. The resubmergence trials took place in the Summer of 2024, sampling oysters from three off-bottom mariculture sites in two separate trial runs. Sampling schedules were chosen to align with peak and fringe times within South Carolina Vibrio control months (between July - September). The chosen schedule prioritized Vibrio data collection from Day 0 (Post-flip), Day 7, Day 9, and Day 14 after the flip. Industry partners included Lowcountry Oyster Co, Lady’s Island Oyster, and Barrier Island Oyster Company. Sampling and analysis also required a multi-agency collaboration between SCDNR shellfish research section, SCDNR shellfish management section, SC Department of Environmental Services (SCDES, formerly SCDHEC) shellfish sanitation, US Department of Agriculture USDA FDA Gulf Coast Seafood Laboratory (GCSL), and S.C. Sea Grant Consortium.

All three industry partners (LOWCO, LIO, BIO) provided, and were compensated for, market size triploid oysters (≥ 3in.), as well as compensation for their time spent rearing the oysters and their crucial participation in this collaborative research project. For each trial performed, growers were responsible for deploying and stocking four off-bottom cages (2 control, 2 treatment) with 150 oysters per bag at an unused location on their lease. Cages were tagged and deployed with continuous salinity and temperature loggers two weeks prior to the start of each trial, giving the animals time to acclimate to the study site conditions. Once deployed, growers relinquished care of the cages to the resubmergence project team over the two-week trial period. At the conclusion of each sampling run, the growers assumed responsibility and reclaimed their gear with remaining oysters.

Using available temperature and salinity data July, August, and September were chosen as “most likely to occur” time points within Vibrio control months. Meetings prior to the trials resulted in a sampling schedule that considered policy development goals, feasible shipping/delivery acceptance days to GCSL FDA Vibrio Lab (Dauphin Island, AL) and agency availabilities at SCDNR and Sea Grant. The chosen schedule prioritized Vibrio data collection from Day 0 (Post-flip), Day 7, Day 9, and Day 14 after the flip.

Growers were responsible for grading 150 market ready (~3”) oysters and stocking them in four 6-bag floating cage systems two weeks before the start of each trial. After a two-week acclimatization period, two cages labeled for treatment were flipped to air dry for approximately 16 hours (flipped up ~4pm, back down ~10am). Sampling from both control and treatment cages commenced the following day (Day 0/Post). Loggers attached to control and treatment cages recorded continuous water quality for the duration of the trial. Water quality, weather, and environmental data were also collected each sampling day at the time of collection, utilizing the pre-prepared data sheets. The original design called for 150 g of wet tissue (~15 oysters size dependent) per bag at each sampling event. Successful completion of both trials would have resulted in 24 treatment samples per mariculture site over the course of the season; 3 treatment samples for each of the 4 sampling days in each trial. However, several occurrences disrupted our schedule and required us to adapt our schedule and our collection expectations.

Adaptations:
Trial 1
Temperature error: To accurately reflect the Vibrio conditions at the time of sampling, the oysters must be first brought within the temperature window for lab acceptance (2-10°C). This temperature range prevents oyster mortality in transit and suspends Vibrio development at the time of collection. The animals must then be packed on ice for shipment with materials that maintain the specific temperature range, consistently until lab arrival. A smart button temperature logger was inserted into one oyster from both a control sample and a treatment (desiccation) sample to track any temperature variations.

Unfortunately, a change in shipping materials from packing peanuts to bubble wrap did not provide an equivalent buffer between ice packs and the samples, allowing the animals to drop to 1°C before arrival. Future shipments returned to the Styrofoam packing peanuts and no further shipments arrived out of temperature range. At this early stage in the trial, we had four total cages in use for each site, two controls and two treatments, with six bags in each cage. The decision was made to exclude the current treatment cages from any further sampling and to restart Trial 1 one week later using the two control cages that had remained submerged. The team went out the following week and flipped one cage, leaving one control and one treatment cage for the duration of the trial. Each of the six bags were collected from twice, resulting in 48 samples per site on this trial.

Inclement Weather: Due to the timing of the trials, inclement weather including tropical storms and hurricanes can be expected. On Friday July 26th the Charleston area experienced an afternoon rain event that flooded the region. The following morning it was learned that one of the cages at the Lowcountry site had flipped during the storm. As we had already reduced the number of cages by half, adjusting for the initial shipment that was received under temperature, we made the collective decision to discontinue Lowcountry sampling for this round. We concluded Trial 1 using only samples from Lady’s Island and Barrier Island.

As we neared the end of Trial 1, Tropical Storm Debby arrived, stalling over the state of South Carolina from August 5th through the 9th. This storm contributed to historic rainfall across the state and impacted the Lowcountry for several weeks as water drained through the coastal tributaries and estuaries. Samples were able to be collected early Monday morning to conclude Trial 1 for Lady’s Island and Barrier Island sites, though the volume of rain left concerns about salinity and freshwater drainage for the remainder of the sampling season.

Shipping Error: Maintaining consistent temperature for all 18 samples during each shipping event requires a specific packaging protocol developed through several test shipments. For successful shipment of 18 samples, 2 separate boxes (21x12x10”) are lined with an insulated, sealable bag. The box is then packed in layers with ice packs, bagged Styrofoam packing material, and samples. The animals are always separated from ice packs with a buffer. Through trial and error, we have determined this to be the best way to maintain temperature during shipping. This protocol worked well for each shipment until Day 7 of the second trial, when the two sampling boxes were separated by FedEx in Memphis, leaving one box of samples behind. The second box was eventually delivered to the lab; however, it arrived outside the 24-hour delivery window. The box that arrived on time contained all 6 Lady’s Island samples; however, as we did not have complete samples for Barrier Island or Lowcountry, the Day 7 samples for Trial 2 were lost for those sites. Moving forward we were able to repeat our adaptation from Trial 1, flipping 1 of the control cages, to restart Trial 2 with Barrier Island. Due to scheduling conflicts and staffing constraints outside of the agreed upon schedule with SCDNR, the team decided not to move forward with Lowcountry sampling for Trial 2. We were able to complete Lady’s Island Trial 2 on schedule, and Barrier Island Trial 2 with a one-week delay. Future shipments consisting of more than 1 box will be packaged together inside one larger box to ensure separation does not occur.

Summary of lessons learned:
Sampling and shipping protocol changes were necessarily adopted as situations arose. Though the weather and environmental impacts disrupted sampling schedules and practices, they accurately reflect the conditions of these farms as they operate in an open marine setting. Historic rainfall and storm conditions are a reality for harvests that occur during the summer months. While the shipping errors were unfortunate, a study of this nature had not previously been conducted across state lines, in this manner. Transport and shipment of live animals are common obstacles in industry and working with shipment schedules and handling practices require protocol adjustments. These changes were documented to ensure no future loss of sampling data. In the end, 2 full 14-day trials were conducted at 2 sites (BIO and LI).

Recommendations: Proposed Research Plan for Summer 2025
Leading up to the summer of 2024, the industry had expressed an interest in determining the safety of diploid oysters during the summer months, and plans were made to include sampling diploid oysters alongside triploid oysters during summer 2025 to evaluate if there was any significant difference in vibrio levels across ploidy. On December 4, 2024, SC DES communicated FDA’s interpretation of the summer 2024 results to Sea Grant. It was relayed that FDA’s conclusion is that these results indicate that 14 days is still the optimal resubmergence time in South Carolina, and that FDA recommends to only focus on diploid vs. triploid sampling in 2025 due to cost and capacity on their end. After some conversations with industry members, Sea Grant organized a call with FDA and SC DES on January 22, 2025 to communicate to them that the project team and others in the industry in SC are still interested in the 14-day resubmergence research question in addition to the diploid vs. triploid question, and to ensure that FDA’s decision to recommend forgoing resubmergence sampling and only focusing on the diploid vs. triploid question in summer 2025 was not driven by any potential misconceptions about what the industry wants. FDA communicated to Sea Grant that that even if summer 2025 sampling indicated that 7 or 9 days was safe, that the 2024 results will drive the FDA to conclude to err on the safest side and stick with the 14-day regulation. Due to that decision, SC DES would not pursue a statutory change to the 14-day requirement. Therefore, 14 days of resubmergence prior to harvest in SC will remain in place based on the 2024 data.

Since January 28, 2025, and as of March 21, 2025, FDA has been unable to communicate whatsoever with the rest of the project team as the Department of Health and Human Services has issued a pause on mass communications and public appearances that are not directly related to emergencies or critical to preserving health.

Results from FDA on the 2024 trials can be found here: Fa23-SC-01 Interim Report FINAL Nov2024 (1)

The trial calendar can be found here: 2024 trial calendar

Sampling Protocol developed here: 

Sampling Kit Information:

The sampling kits contain 6 bags for each site, 3 control and 3 treatment sets. Control 1 and Treatment 1 bags will both include Data Sheet 1 and Data Sheet 2, the zip tie for securing the Smart Buttons inside an oyster, a lab programmed Smart Button, and a mesh bag for collecting oysters.

The lab programs the Smart Buttons to collect temperature data for a specific window of time. Each Smart Button arrives from the lab in an individual plastic bag labeled Control or Desiccation and is labeled for the dates they are active. As the Smart Buttons cannot be modified or substituted once they arrive, it is crucial to place them in the corresponding Control 1 or Treatment 1 bags. Smart Buttons are not waterproof; do not remove them from their individual labeled plastic bags.

Once Smart Buttons have arrived the Sampling Kit for the corresponding sample day may be assembled. Once they are assembled and the sampling day is confirmed, deliver to the corresponding site team at Sea Grant or DNR. Bag delivery should be at least 24 hours before sampling.

Packing Protocol developed here:

Packing Protocol: 

1. Upon arriving at the packaging facility, first check the temperature of several oysters from each bag. Depending on the temperature and conditions of the day, they will have risen slightly during transport. The target for lab acceptance is between 2-10°C, our aim for shipping is between 3-7°C.
2. Prepare another ice slurry of 2:1 saltwater: ice (or reuse the one from the landing site). In our experience, many oysters will register between 12-20 °C upon arrival at the packaging facility. This varies depending on how much ice is in the cooler, how evenly the oysters are spread across ice or if the bags were stacked on top of one another during transport, etc.
3. Begin dipping the oysters into the slurry at 30 second intervals, checking the temperature of individual oysters removed from the mesh bag. We have found that dipping 3 bags at a time in the cooler as well as reaching into the slurry to shake and distribute the oysters in their bag, is the best way to ensure all the oysters drop in temperature at the same rate.
4. After dipping the oysters for 30 seconds, remove the bag and gently shake it for a few seconds to drain excess water and bring the bags indoors. We found that an air conditioned facility on the hotter days in August prevents tge temperature of the bags from rising again while packing.
5. Moving through one bag at a time to ensure oysters from different bags aren’t crossed, empty each bag and begin individually checking the temperature of each oyster. We have found that with such variability in transport times and methods, this is the best way to ensure all oysters have been brought within lab acceptable temperature range.
6. As soon as all oysters in a mesh bag have been brought to temp, immediately place them back in their designated plastic bag and roll the bag for packaging. Rolling them into cylindrical form allows us to fit between 3-4 samples per row. Place the rolled bag into the prepared shipping container.
7. Place your samples in the shipping container, this should be prepared with a layer of ice packs on the bottom and a thin layer of packing peanuts on top of the ice packs to ensure no oysters come in direct contact with the ice. 3-4 sample bags should fit a row, top with another thin layer of packing peanuts. Repeat the ice pack/peanut layer again before adding another row of sampling bags.
   1. It is worth noting that other buffer material may be used and bubble wrap was suggested; however, the density of the peanuts prevents the ice packs from dropping the temperature too low.
8. The boxes used fit 2 rows of samples or up to 8 bags. Once the box is full, place the complete In-Cooler data sheets inside a plastic bag on top of the samples and immediately seal the box.
9. Attach the pre-printed shipping label to the exterior and place the box in the walk-in cooler to await Fed-Ex pickup. Scan Out-of-Cooler sheets on phone for email to lab.

Policy Analysis update (Objective #4): 

The global fisheries market is undergoing significant transformation. Overfishing has emerged as a global issue, with estimates suggesting that one-third of the world’s fisheries are either overfished or over-exploited (Ritchie & Roser, 2023). While wild fishing in both U.S. and international waters has declined, seafood consumption remains steady. Mariculture, or marine aquaculture, now accounts for over 50 percent of global seafood production, with oysters leading the market in both production and sales (FAO, 2016; NOAA & U.S. Department of Commerce, 2024). In the United States, the aquaculture industry has experienced substantial growth, with production increasing nearly ninefold between 1987 and 2017, though China continues to dominate as the world’s largest supplier of cultivated oysters (Botta et al., 2020; Naylor et al., 2021).

In South Carolina, the expansion of sustainable mariculture practices is of critical importance. Bivalve mariculture, particularly oysters, plays a vital role in supporting coastal ecosystems by filtering water, reducing erosion, and providing essential habitat, among other vital ecosystem services. The commercial shellfish industry also bolsters rural economies and supports working waterfronts in coastal communities that have seen economic decline in recent decades (Coen et al., 2007; Barrett et al., 2022; Varshanidze et al., 2023). Beyond these economic and environmental benefits, Michaelis et al. (2021) emphasizes the concept of cultural ecosystem services, underscoring how shellfish cultivation and consumption contribute to community well-being and cultural identity. Oysters hold a special place in South Carolina’s Lowcountry culture, featured prominently in the region's art, literature, and cuisine. Evidence of oyster consumption in the area dates back approximately 4,000 years, with indigenous middens containing shells used for food and tools (Burrell, 2003). In colonial times, the area now known as Charleston was originally called Oyster Point, with a nearby body of water named Oyster Bay (Burrell, 2003). Despite this rich cultural heritage, only about 1 out of every 5 of the oysters consumed in South Carolina are locally cultivated (Von Nessen, 2021). As an agricultural state, South Carolina has an opportunity to leverage its tidal marshes, providing both economic benefits through local oyster production and environmental advantages through sustainable mariculture practices. By managing the use of public lands and resources, shellfish mariculture offers a vital food source and an important contribution to the state’s economy.

Stagnant Growth and Industry Relations

Despite this seemingly primed opportunity, South Carolina’s mariculture industry has lagged its peers in growth (Fodrie et al., 2018; Revell & Hill, 2021). Researchers attribute this stagnation to challenges in policy, regulation, and management practices (Lester et al., 2022; Naylor et al., 2021). At the national level, many in the agricultural sector argue that overly stringent or under-resourced regulatory bodies hinder expansion and stifles modern agriculture’s financial viability (Green et al., 2023). The concept of administrative burden as a political tool to inhibit public resources is more often applied to social programs but can be used in the regulatory space as well. As the aquaculture industry evolves with new technologies and practices, state regulatory agencies must adapt quickly to keep pace. An effective policy must be dynamic, ensuring both economic viability and sustainability. However, the complexity of the industry necessitates a coordinated, multi-agency approach to governance. The success of mariculture depends on efficient regulation that balances industry growth, public health, and ecosystem services.

South Carolina’s shellfish industry is itself a complex network of agencies, organizations, and stakeholders (see Figure 1). Regulatory oversight is divided among multiple entities: the South Carolina Department of Resources (SCDNR), the South Carolina Department of Environmental Services (SCDES), and the United States Army Corps of Engineers (USACE), each handling distinct aspects of permitting and enforcement. Industry advocacy groups, such as the South Carolina Shellfish Growers Association (SCSGA) and the East Coast Shellfish Growers Association, work to ensure legislative protection for shellfish farmers (Sabatier, 1987). Nonprofit environmental organizations like the South Carolina Oyster Restoration and Enhancement (SCORE) program and The Nature Conservancy contribute to sustainability efforts. The South Carolina Sea Grant Consortium (SCSGC) serves as a bridge between these stakeholders, fostering collaboration.

Private industry operators—ranging from large businesses to smaller, independent farmers—also play a crucial role in the sector’s growth and stability. While these groups may engage with formal coalitions, their daily operations often center on peer-to-peer collaboration. The health of these inter-organizational relationships is vital to industry’s functionality. Despite their independent roles, stakeholders remain interconnected, and only through effective collaboration can their diverse interests be successfully pursued. The shellfish industry in South Carolina is a complex ecosystem in its own right (see figure 1), with a variety of agencies and organizations invested in the future of shellfish. Each governing agency carries its own identity and agenda with a different piece of the policy and regulatory puzzle. The South Carolina Department of Resources (SCDNR), the South Carolina Department of Environmental Services (SCDES) and the United States Army Corps of Engineers (USACE) all serve distinct and separate roles in the enforcement and permitting process for the mariculture sector. Agricultural suppliers and organizations such as the South Carolina Shellfish Growers Association (SCSGA) and East Coast Shellfish Growers Association are lobbying organizations that operate as advocacy coalitions (Sabatier, 1987) to ensure their interests are represented and protected in legislature.

South Carolina Oyster Restoration and Enhancement program (SCORE) and The Nature Conservancy are non-profit environmental stewardship organizations invested heavily in shellfish aquaculture, examples of another coalition. South Carolina Sea Grant Consortium (SCSGC) operates as a boundary spanning agency between the differing stakeholders, drawing together resources and relationships. A final coalition of stakeholders could be seen in the private industry operators running large businesses employing local citizens and supplying the local hospitality industry with products. Though they may participate in varying degrees in other coalitions, the workers who own and operate their farms on a day-to-day basis in S.C. tend to work more closely with one another than with the more formal organizations. The functionality and health of the relationships between these organizations are critical factors that make up the larger industry, but relationships and collaboration between parties can become strained. Though they operate independently of one another, they are still inextricably linked through industry management and operations, and it is only through successful collaboration that all agendas can successfully be pursued.

Ecology of Games and Advocacy Coalition Framework

Polycentric governance is a defining feature of the U.S. regulatory system, particularly in managing complex, multifaceted issues. This structure is best understood through Lubell et al.’s (2023) Ecology of Games Framework (EGF), which examines how multiple stakeholders interact within interconnected policy arenas. EGF conceptualizes each stakeholder group as a distinct "game," where policy actors rally around specific issues and engage in debate within designated forums. However, these groups do not operate in isolation; rather, they function within a larger system of interdependent games (Lubell et al., 2023).

Policy actors in this framework can range from individuals to large government agencies. In the context of South Carolina’s shellfish aquaculture industry, each regulatory agency, advocacy organization, and stakeholder coalition constitutes a separate game, with its own agendas, values, and priorities. While these entities act autonomously to fulfill their objectives, they must also collaborate to ensure industry-wide governance. This interplay creates a balancing act, requiring coordination between private enterprises, public health interests, and the sustainable management of natural resources.

Policy Actors and Coalitions

Each government agency that regulates the permitting process, rules and regulations of the industry operates with their own agenda, empowered by different and at times competing statutes. At the federal level, the U.S. Army Corps of Engineers (USACE) plays a crucial role in the permitting process for oyster mariculture in South Carolina by overseeing activities that may impact navigable waters and wetlands. Private landowners may own the property leading up to the marsh, but any connected body of water that meets the navigable waters criteria is subject to and under federal jurisdiction by The Public Trust Doctrine and The Commerce Clause of the United States Constitution. USACE derives its regulatory guidelines and power primarily from the Rivers and Harbors Act of 1899 (Section 10), which provides federal oversight of any construction, commerce or activities in navigable waters (Salzman & Thompson, 2003). Additionally, USACE is responsible for permitting discharge or any activity that may alter the integrity of the wetlands under Section 404 of the Clean Water Act (Salzman & Thompson, 2003). The landmark Supreme Court decision Rapanos v. United States, 547 US 715 (2006) further defined the boundaries of navigable waters under the Clean Water Act as those that should cover wetlands with a “significant nexus” to navigable waters and only those wetlands with a “continuous surface water connection” (Salzman & Thompson, 2003). The USACE section of the permitting process involves reviewing applications to assess potential environmental impacts with this legislation in mind. By enforcing these regulations, USACE seeks to balance economic development with the protection of aquatic ecosystems, making its role integral to sustainable oyster farming in the region.

At the state level, the South Carolina Pollution Control Act (SCPCA) established the South Carolina Department of Environmental Services (SCDES), previously known as the Department of Health and Environmental Control, to create and empower an agency tasked with monitoring water quality and preventing foodborne illnesses (Wastewater Laws and Regulations | South Carolina Department of Environmental Services, n.d.). The designated bureau within SCDES that handles shellfish mariculture applications is the Bureau of Coastal Management (BCM). Undercooked or raw seafood can pose a public health risk due to the Vibrio bacteria that is endemic to our warm, southern waters. Norovirus, a virus caused by the introduction of human waste as point source or non-point source discharge through a number of activities, is the most common foodborne illness in the United States (Murray et al., 2023). As natural filters, oysters typically carry a small number of bacteria or viruses at levels low enough to be safe for human consumption; however, oysters grown in areas of poor water quality, known contamination or not carefully cultivated in the warm summer months can carry serious risk of illness. Ensuring that farms are operated in manner that is in compliance with the SCPCA and public health standards for agricultural products to prevent foodborne illnesses makes SCDES an integral part of the permit application. Agency approval for any new business venture must submit a number of documents for review with detailed descriptions or sketches of gear that will be used and the parcel desired with detailed maps and GPS coordinates. SCDES utilizes interagency research, data obtained through collaboration with research institutions and state agencies, and its rulemaking authority granted by the SCPCA to regulate the cultivation and sale of oysters. The rulemaking process, conducted through notice-and-comment procedures, enables SCDES to operate with a degree of autonomy while ensuring public input and participation in a non-elected bureaucracy.

South Carolina Department of Natural Resources is the final permitting government agency that farmers must receive approval from before they may begin work. As the state agency responsible for resource management and protection, SCDNR is the largest of the three agencies and their interest in the shellfish industry is two-fold. The Marine Resources Research Institute (MRRI) at SCDNR seeks to monitor and protect the state’s ecosystems, valuing the role that oysters carry in marine systems as an indicator and keystone species. The ecosystem services provided by oysters in the

The Lowcountry’s shellfish ecosystems provide critical benefits to both wildlife and human populations. The Shellfish Management Division of the South Carolina Department of Natural Resources (SCDNR) oversees shellfish bed activities, promotes responsible harvesting and cultivation, and ensures that industry members adhere to sustainable practices.

Industry advocacy groups, such as the East Coast Shellfish Growers Association (ECSGA) and the South Carolina Shellfish Growers Association (SCSGA), work with legislators at both the state and regional levels to promote practical and equitable regulations. These organizations exemplify Advocacy Coalitions, a concept from Sabatier’s (1987) Advocacy Coalition Framework (ACF), which describes groups of individuals and organizations aligned by shared core beliefs working collaboratively to influence policy. Similarly, nonprofit organizations such as The Nature Conservancy (TNC) and South Carolina Oyster Restoration and Enhancement (SCORE), an SCDNR affiliate focused on oyster restoration, engage with both the public and private sectors to protect shellfish populations and coastal ecosystems.

Private citizens are also key stakeholders, as shellfish aquaculture operates in public waterways. The right to access and enjoy navigable waters belongs to all residents, meaning that aquaculture businesses must consider the concerns of taxpayers and local communities. In some cases, waterfront property owners organize coalitions to oppose shellfish farming near their properties, often through homeowners' associations (HOAs) or public advocacy campaigns. These conflicts frequently stem from misconceptions about oyster aquaculture—many opponents envision large-scale, industrial floating farms rather than the reality of small, periodically buoyed cages. Despite this, opposition to aquaculture near residential waterfronts is becoming increasingly common, with some property owners attempting to assert control over public waterways.

Finally, the private sector plays a crucial role in South Carolina’s shellfish aquaculture industry. While business owners may cultivate oysters on private property, these shellfish require active marine environments and tidal bodies to thrive. Because water quality is not confined to property boundaries, the impact of private aquaculture operations extends across ecosystems. Oysters, as natural water filters, contribute to maintaining water quality, but those grown in stagnant or contained areas must, by law, be submerged in open waterways for at least fourteen days before they can be sold. This requirement underscores the industry's reliance on public waters, making collaboration with regulatory agencies and other stakeholders essential to business strategy.

The Ecology of Games Framework (EGF) is particularly relevant to environmental policy issues like aquaculture, which require a collaborative approach. This industry presents a collective action challenge, balancing private interests with public welfare and shared natural resources (Lubell et al., 2023). Policy forums serve as arenas for negotiation, where stakeholders engage in learning, cooperation, and bargaining. The resulting rules and regulations, shaped through these interactions, help manage and sustain common-pool resources.

Shellfish aquaculture in South Carolina holds significant potential for economic growth, coastal revitalization, and ecosystem sustainability. For comparison, Rhode Island currently has 84 active aquaculture permits—99% of which are for oysters—while Virginia’s aquaculture industry contributed an impressive $64 million to the economy in 2023. In contrast, South Carolina’s industry generated only about $1.2 million in the same year (NOAA & U.S. Department of Commerce, 2024). These figures highlight the opportunity for expansion in this environmentally sustainable sector, which has deep cultural roots in the state. However, realizing this potential depends on improving regulatory efficiency, strengthening industry relationships, and streamlining permitting processes. By applying frameworks such as the Advocacy Coalition Framework (ACF) and Ecology of Games Framework (EGF), policymakers and industry leaders can better analyze stakeholder dynamics, assess regulatory effectiveness, and identify areas with undue administrative burden to ultimately helping to foster industry growth.

Figure 1:  Figure 1 Key Industry Stakeholders

References

Barrett, L. T., Theuerkauf, S. J., Rose, J. M., Alleway, H. K., Bricker, S. B., Parker, M., Petrolia, D. R., & Jones, R. C. (2022). Sustainable growth of non-fed aquaculture can generate valuable ecosystem benefits. Ecosystem Services, 53, 101396. https://doi.org/10.1016/j.ecoser.2021.101396

Burrell, V. G. (2003). The Oyster Industry in South Carolina.

Botta, R., Asche, F., Borsum, J. S., & Camp, E. V. (2020). A review of global oyster aquaculture production and consumption. Marine Policy, 117, 103952. https://doi.org/10.1016/j.marpol.2020.103952

Coen, L., Brumbaugh, R., Bushek, D., Grizzle, R., Luckenbach, M., Posey, M., Powers, S., & Tolley, S. (2007). Ecosystem services related to oyster restoration. Marine Ecology Progress Series, 341, 303–307. https://doi.org/10.3354/meps341303

Fodrie, J., Peterson, C., Voss, C., & Baillie, C. (2018). North Carolina Strategic Plan for Shellfish Mariculture: A Plan To 2030. North Carolina Shellfish Mariculture Advisory Committee.

Lester, S. E., Gentry, R. R., Lemoine, H. R., Froehlich, H. E., Gardner, L. D., Rennick, M., Ruff, E. O., & Thompson, K. D. (2022). Diverse state‐level marine aquaculture policy in the United States: Opportunities and barriers for industry development. Reviews in Aquaculture, 14(2), 890–906. https://doi.org/10.1111/raq.12631

Lubell, M., Mewhirter, J., & Robbins, M. (2023). The ecology of games framework: Complexity in polycentric governance. In Theories of the policy process (5th ed., pp. 26). Routledge

Murray, G. D., Fail, R., Fairbanks, L., Campbell, L. M., D’Anna, L., & Stoll, J. (2023). Seafood consumption and the management of shellfish aquaculture. Marine Policy, 150, 105534. https://doi.org/10.1016/j.marpol.2023.105534

Naylor, R. L., Hardy, R. W., Buschmann, A. H., Bush, S. R., Cao, L., Klinger, D. H., Little, D. C., Lubchenco, J., Shumway, S. E., & Troell, M. (2021). A 20-year retrospective review of global aquaculture. Nature, 591(7851), 551–563. https://doi.org/10.1038/s41586-021-03308-6

NOAA, & U.S. Department of Commerce. (2024, April 4). Fisheries of the United States | NOAA Fisheries (National). NOAA. https://www.fisheries.noaa.gov/national/sustainable-fisheries/fisheries-united-states

Revell, H., & Hill, K. (n.d.). 2021 Oyster Mariculture in Georgia Updates to the Legal and Regulatory Framework.

Ritchie, H., & Roser, M. (2023). Fish and Overfishing. Our World in Data. https://ourworldindata.org/fish-and-overfishing

Salzman, J., & Thompson, B. (2003). Environmental Law and Policy. Foundation Press.

Varshanidze, N., Popluga, D., & Latvia University of Life Sciences and Technologies. (2023). Blue economy: Analyzing aquaculture farms on the example of the autonomous republic of Adjara (Georgia). 106–113. https://doi.org/10.22616/ESRD.2023.57.010

Von Nessen, J. (2021). Benefits of Increased Shellfish-Mariculture Production (Research Economy No. SCSGC-T-21-05; p. 32). S.C. Sea Grant Consortium. https://www.scseagrant.org/wp-content/uploads/Benefits-of-Increased-Shellfish-Mariculture-Production.pdf

Wastewater Laws and Regulations | South Carolina Department of Environmental Services. (n.d.). Retrieved from https://des.sc.gov/programs/bureau-water/wastewater/wastewater-laws-and-regulations