Date of Award


Document Type


Degree Name

Master of Science (MS)


College of Science and Mathematics


Marine Biology and Coastal Sciences

Thesis Sponsor/Dissertation Chair/Project Chair

Paul Bologna

Committee Member

Robert Prezant

Committee Member

Jorge Lorenzo Trueba


Porifera is an important phylum of organisms in benthic ecosystems that filter water, act as biogenic habitat, and provide 3-dimentional structure. Sponge diversity and abundance are often used as bio-indicators for good or improving water quality in a system. Transects were performed during July 2015, January 2016, and July 2016 to determine species richness, density, and assess necrotic pinacoderm tissue decay of species of poriferans in St. John, USVI. 6,800 individuals and 17 different species were recorded during observation periods in Great and Little Lameshur Bays. Results indicate that the non-cryptic species Amphimedon compressa and Aplysina fiulva had the highest population densities and showed differences in depth distributions between these bays. Among cryptic species, results indicate that Ectyoplasia ferox, Phorbas amaranthus, and Diplastrella megastellata had the highest densities, but the pattern varied between depth and site. Great Lameshur Bay showed higher species richness and population density compared to Little Lameshur Bay, possibly due to benthic topography and substratum composition. In the summer of 2016, disease prevalence for Amphimedon compressa and Aplysina fulva increased from previous surveys performed in January 2016, but remained very low and the mechanism behind this increase remains unknown. This research represents the first evaluation of shallow sponge communities in this area and provides baseline data for future evaluations of system health.

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