Aquaculture 2025

March 6 - 10, 2025

New Orleans, Louisiana USA

Add To Calendar 09/03/2025 11:15:0009/03/2025 11:35:00America/ChicagoAquaculture 2025IDENTIFYING ACUTE STRESSFUL CONDITIONS IN FOUR LOUISIANA OYSTER HABITATS FROM HIGH FREQUENCY DATASalon EThe World Aquaculture Societyjohnc@was.orgfalseDD/MM/YYYYanrl65yqlzh3g1q0dme13067

IDENTIFYING ACUTE STRESSFUL CONDITIONS IN FOUR LOUISIANA OYSTER HABITATS FROM HIGH FREQUENCY DATA

Shelby A. Perry, Beth A. Stauffer, and Megan K. La Peyre

 

Department of Biology

University of Louisiana at Lafayette

Lafayette, Louisiana 70504

Shelby.perry@louisiana.edu

 



Estuarine habitats are experiencing increasing change due to the effects of climate change and other anthropogenic stressors. Increasing temperatures, continued agricultural runoff, hypoxic zones, and changes in salinity are all factors that can affect the growth, success, and mortality of eastern oysters (Crassostrea virginica). As both oyster fisheries and aquaculture face these dynamic conditions, understanding and identifying the frequency and duration of stressful conditions and how they interface with eastern oyster tolerance ranges is key to better prediction of habitat suitability for oysters in key growing areas. Many habitat suitability indices for oysters rely on monthly averages of environmental data; however, it is likely that acute stressful conditions are still occurring within the months represented by those mean conditions, even in sites considered suitable. To test this hypothesis, continuous monitoring data collected every 15 minutes from four oyster-growing regions in Louisiana were analyzed to determine exposure to stressful conditions from temperature, salinity, dissolved oxygen, or phytoplankton biomass (as chlorophyll-a). Stressful events were assessed as either lethal and nonlethal based on published tolerance ranges (or optima). Preliminary data shows a general absence of lethal synergistic stressors in the four systems and 18 months of data analyzed thus far. Nonlethal stressors occurred at frequencies in excess of 17 events in the study period, lasting upwards of 31 days, with West Cove having the highest number events. Overall, dissolved oxygen as a nonlethal stressor (x < 4 mg/L) was observed most frequently with durations ranging from 2-31 days. Additionally, temporal trends of nonlethal stressor events showed higher frequencies in summer months (May-August). Additional results including frequency, duration, and overall site scoring, as well as recommendations for incorporating such analyses into oyster aquaculture site selection, will be further discussed.