By Hailey Murphy, S.C. Sea Grant Consortium.
Kate Chatman, Consortium Shellfish Aquaculture Graduate Assistant, holding an oyster with monitoring equipment. Photo credit: Hailey Murphy/S.C. Sea Grant Consortium.
The first round of sampling in a study on Vibrio spp. levels in farmed oysters during routine cage drying was conducted this summer by the S.C. Sea Grant Consortium and the South Carolina Department of Natural Resources. This study was made possible through partnerships with Lady’s Island Oyster, Lowcountry Oyster Company, and Barrier Island Oyster Company farm managers, in addition to close coordination with the South Carolina Department of Environmental Services and the Food and Drug Administration (FDA) lab in Dauphin Island, AL. Results of the study will be used to inform policies focused on best management practices to reduce pathogen risks while ensuring food safety standards.
Oyster cages in a tidal creek off the coast of Beaufort, S.C. Photo credit: Hailey Murphy/S.C. Sea Grant Consortium.
Advancements in gear technology and the ability to generate year-round revenue through triploid summer harvest have enabled the expansion of the oyster aquaculture industry in South Carolina. With the allowance of summer harvest, extra precautions are taken to ensure human health risks associated with consuming raw seafood are minimized. Regulations require aquaculture oysters to be submerged on lease sites for a consecutive 14 days during warmer summer months.
Farmers must strike a balance between maximizing production efficiency while providing a safe, sustainable product, and have requested an in-depth study on best management practices for this resubmergence requirement. The collection of Vibrio spp. data at the local (e.g., state-specific) level may enable an optimization of resubmergence requirements; though to do so, cooperation across multiple state and federal agencies is necessary. The study’s objectives are to collect field data, understand inter-agency communications, and use these locally collected field data to inform policy in maximizing agricultural sustainability and efficiency for the coastal shellfish aquaculture industry.
Researchers Kate Chatman, Consortium Shellfish Aquaculture Graduate Assistant, and Sarah Pedigo, former Consortium Shellfish Aquaculture Specialist, carrying chilled oysters in a cooler for sampling. Oyster cages in a tidal creek off the coast of Beaufort, S.C. Photo credit: Hailey Murphy/S.C. Sea Grant Consortium.
This summer, oyster tissue samples were collected at two different farms, Lady’s Island Oyster and Barrier Island Oyster Company, for analysis of Vibrio spp. at specific post-air-drying dates throughout the 14-day resubmergence period. Samples were also collected from untreated cages to act as a control. Kate Chatman was hired in the summer of 2024 as the Shellfish Aquaculture Graduate Assistant and has assisted with the coordination and facilitation of project objectives and the experimental trials. Field sampling will resume during the summer of 2025, while the policy analysis of the current state of regulations and mechanisms required for policy change is slated to begin later in 2024 and continue into 2025. Learn more at the Oyster Resubmergence Trials webpage.
Please direct any questions to Matt Gorstein, Director for Development and Extension, or Kate Chatman, Shellfish Aquaculture Graduate Assistant.