Comparison of Perkinsus marinus infection and oyster condition in southeastern North Carolina tidal creeks
- UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
- Sara L. Colosimo (Creator)
- Institution
- The University of North Carolina Wilmington (UNCW )
- Web Site: http://library.uncw.edu/
- Advisor
- Martin Posey
Abstract: The Eastern oyster (Crassostrea virginica) is a commercially important species
that also performs critical ecosystem functions, affecting water quality and providing
habitat for fish and invertebrates. However, populations of C. virginica have drastically
declined, especially over the last 50 years. In recent years, disease caused by the
protozoan parasite, Perkinsus marinus (Dermo), has been a major factor contributing to
the decline of oyster populations. Exposure to one or more environmental stressors, such
as increased particulate loading and declining water quality, may adversely affect oysters,
making them more susceptible to infection. This study compares P. marinus infection in
intertidal oysters from three tidal creeks in southeastern North Carolina that vary in
historic water quality conditions. Prevalence and intensity of P. marinus infection was
compared over time and among creeks for both natural oyster populations and hatchery
stock outplants using RFTM tissue assay. Oyster tissue condition, growth, and mortality
were also compared. Infection was nearly 100% prevalent across sampling periods,
among creeks, and in both hatchery and natural oysters. However, despite high
prevalence, overall infection intensities were low. Infection intensity among the creeks
did not follow historic water quality patterns, but did vary with specific factors.
Temporal patterns of P. marinus infection and tissue condition were apparent in both
hatchery and natural oysters. Infection intensities were highest and oyster condition was
lowest during November 2005 while infection was at its lowest and condition was at its
highest in February 2006. Infection levels and condition also differed between oyster
types with hatchery oysters having higher infection intensity and lower condition than
natural oysters. Infection intensity and oyster condition were also correlated with aspects of water quality in the tidal creeks. The results of this study have implications not only
for restoration, but also for understanding oyster and parasite biology in the intertidal
environment. They suggest that conditions of the intertidal environment may impact
seasonal cycles of P. marinus infection in the southeastern United States and may even
affect the parasite itself. Overall, the results underscore the idea that a variety of factors
likely interact to influence P. marinus infection levels in oysters and oyster health.
Comparison of Perkinsus marinus infection and oyster condition in southeastern North Carolina tidal creeks
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Created on 1/1/2009
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Additional Information
- Publication
- Thesis
- A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment of the Requirement for the Degree of Masters of Science
- Language: English
- Date: 2009
- Keywords
- Oysters--Diseases--North Carolina, American oyster--Diseases
- Subjects
- Oysters -- Diseases -- North Carolina
- American oyster -- Diseases