Date of Award

Spring 5-5-2023

Document Type


Degree Name

Bachelor of Science (BS)


Marine Science


College of Science

First Advisor

Juliana M. Harding


Eastern Oysters (Crassostrea virginica) host parasites including Perkinsus marinus that infect oyster hemocytes causing emaciation which reduces filtration within the estuaries. Dermo, the disease caused by P. marinus, reduces oyster growth and fecundity and increases seasonal oyster mortality. Dermo activity increases at water temperatures above 25°C and salinities greater than 12 psu. This research quantified seasonal P. marinus prevalence and density in North Inlet and Murrells Inlet oysters collected from December 2020 to December 2022. Oysters (n>6) were collected at least quarterly from subtidal populations Clambank (North Inlet) and Crazy Sister (Murrells Inlet). Oyster shell length (mm) was measured when mantle tissue samples were removed, weighed (g), and incubated to describe parasite prevalence and intensity. Individual parasites were counted with a compound microscope to quantify parasite intensity or density per tissue sample. Prevalence (number of infected individuals/number of individuals in a sample) stayed consistent through the year with prevalence of 99% at Clambank and 100% at Crazy Sister. Parasite intensity varied with seasonal changes with highest intensities during the late summer with water temperatures and salinity of >26℃ and >25-30 psu, respectively. The lowest intensities were observed in late winter and early spring when water temperature and salinity were ~ 10℃ and >15-25 psu. When water temperatures increased, there was an increase in Dermo intensity. P.marinus prevalence and intensity increased seasonally as water temperatures and salinities increased at both sites. Higher Dermo intensity was observed in oysters with shell lengths ≥ 60 mm year-round at both sites.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Available for download on Friday, December 31, 2027