Date of Award

Fall 2019

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)


Ocean Science and Engineering

Committee Chair

Leila Hamdan

Committee Chair School

Ocean Science and Engineering

Committee Member 2

Wei Wu

Committee Member 2 School

Ocean Science and Engineering

Committee Member 3

Kevin Dillon

Committee Member 3 School

Ocean Science and Engineering


Microorganisms are ubiquitously distributed across all aquatic habitats, but it is the environmental conditions of a habitat that determine which microorganisms can thrive in terms of abundance or metabolic activity. Habitats that experience consistent physical and chemical environmental conditions repeatedly favor specific taxonomic groups which may result in a microbial assemblage that is commonly associated with that habitat (i.e., a core microbiome). Core microbiomes have been identified for a variety of natural marine habitats including methane seeps, wood falls, octocoral, and deep-sea sediments. However, it was unknown if the presence of man-made structures on the seafloor, including historic shipwrecks, also resulted in a distinct core microbiome. To determine how historic shipwrecks impact sediment microbiomes under varying environmental conditions, the influence of these structures was examined through bacterial and archaeal 16S rRNA gene amplicon analysis. A distinct sediment core microbiome of wooden-hulled shipwrecks was identified for both bacteria and archaea. Variation of the core microbiome was explained by sediment depth, porosity, total inorganic carbon, and total nitrogen. Results from this study demonstrate that historic shipwrecks on the seafloor modify natural environmental conditions and shape sediment microbial communities.