PhD Dissertation Defense: John Burns

NEW INSIGHTS INTO THE BIOLOGY AND ECOLOGY OF HAWAIIAN CORALS ENABLED BY 3D RECONSTRUCTION TECHNOLOGY

Nearshore coral reef ecosystems have provided a source of sustenance and cultural importance to Hawaiian communities for hundreds of years. Recent research has provided evidence that Hawaiian corals are exhibiting signs of reduced coral health and disease, a scenario likely related to rapid development occurring throughout this region. Marine diseases that affect ecosystem engineers, such as corals, are of particular concern as declines in these organisms can result in dramatic shifts in community structure. Coral health surveys were conducted throughout the Hawaiian archipelago, and multivariate modeling was used to identify demographic parameters associated with the severity of diseases and conditions of reduced health. Population demographics of the host plays an important role in coral health, as the density, diversity, age-, and size structure of a population can affect the severity, extent, and timing of diseases by altering transmission patterns and susceptibility to infection. In order to bridge the gap between disease ecology and large-scale reef processes, I developed innovative techniques to create high-resolution 3D reconstructions of coral reef habitats. The structural complexity of reefs plays a major role in the biodiversity, productivity, and functionality of coral reef ecosystems. The 3D structural properties of the reconstructed reefs were analyzed using geospatial software to determine how each coral species and abiotic feature contributes to the structural complexity of the benthic environment. Temporal analyses were also performed to assess the impacts of acute disturbances and disease on the volume and 3D architectural complexity of coral communities. Loss of live coral cover was found to directly correlate with reductions in both habitat complexity and volume. Furthermore, these techniques were used to map disease lesions on affected coral colonies in a 3D framework. The lesions exhibited statistically distinct clustering across the surface of the affected colonies, thus providing useful information for characterizing disease epizootiology. These cutting-edge techniques can be utilized for an array of research purposes to improve our understanding of how changes in coral composition and habitat structure affect ecosystem processes.

Event Sponsor
Zoology, Mānoa Campus

More Information
John HR Burns, 854-4057, johnhr@hawaii.edu, http://200 W Kawili Street

Tweet