Quantification of circulating hemocytes of  southeastern oysters (Crassostrea virginica) from Sapelo Island, Georgia

REU Fellow: Yasmin Holt, Fort Valley State University

Mentor: Dr. Lisa Brown

Oysters are crucial to the health of ocean ecosystems. They are an important food and habitat source for small, juvenile fish, crabs, and other aquatic species. Their reefs also serve as protection against strong tides and erosion which in return, promotes vegetation growth. They are filter feeders that filter pollution, algae, and other microorganisms through their gills, then releasing clean water back into the surrounding environment. Similar to our own blood and immune systems, oysters contain a fluid plasma known as hemolymph that protects them against harmful bacteria. There are environmental factors that can influence the health and number of immune cells in an oyster. Understanding these factors can help protect these important invertebrates and the underwater creatures that benefit from them. The goal of my study was to evaluate the possible effects of water quality on immune cell count of the southeastern oyster (Crassostrea virginica) across three study sites (Hunt Camp, Cabretta Creek, Dean Creek) in Sapelo Island, Georgia. Cabretta Creek, the site with the highest average salinity, dissolved oxygen, and pH levels yielded three of the highest hemocyte counts for oysters sampled at the site. Hunt Camp had consistently lower hemocyte counts despite little to no difference in water parameter averages to Dean Creek. In future studies, assessments of oyster condition and disease history should be included to determine their effect on oyster hemocyte count.