This project seeks to provide a first characterization of coastal ocean acidification (COA) using the waters of Long Bay, South Carolina (S.C.) where hypoxia (low oxygen) and acidification (in the form of low pH) have already been documented. Project findings will fill a substantial knowledge gap in the Southeast U.S. regarding spatial and temporal trends in coastal and estuarine acidification – the new knowledge generated will provide researchers and coastal managers with a first clear picture of the degree and extent of the COA problem in S.C. waters, and the main drivers behind it. Data from this local characterization will be used in informal and formal education settings to increase public awareness of COA as a statewide coastal concern. The project will serve as a pilot effort to guide future expansion to the rest of the state’s coastline.
Project Findings
A total of 120 samples were collected and analyzed for their dissolved inorganic carbon and total alkalinity content. These observations were collected at four sites from July 5, 2022, to February 6, 2023, and represent the first of their kind within this particular region and will serve to characterize the ocean biogeochemistry of this important coastal zone. pH was also measured in the region by volunteer monitors and the results showed strong linearity with the pH determined by the research team analytically using best practices for OA measurements in the lab. No strong linear relationships were found between total alkalinity and salinity as typically observed within the open ocean, due to the complexity of saltwater and freshwater interactions that occur in estuarine and coastal-ocean systems.
Examining the carbonate system data of the samples provided insights into the condition of the waters of coastal ocean sites and estuaries for the sampling period, including the degrees of saturation of calcite and aragonite, the two most important calcium carbonate minerals synthesized by calcifying organisms. Findings indicate that, while coastal-ocean sites are on par with acidification occurring across the global ocean, at times the observed estuarine sites are experiencing degrees of saturation that reach threatening levels for important taxa such as oysters and flounder.
Resulting Publications
“COASTAL CAROLINA | SOCAN.” 2024. SOCAN. https://socan.secoora.org/coastal-carolina.
Olsen, Mary. (2024). Coastal-Ocean and Estuarine Acidification in Long Bay, South Carolina: A Comparison of In-Situ Water Quality Monitoring with Measured Carbonate System Parameters. Coastal Carolina University.