Disruptions in the coral holobiont have been correlated with disease, which is a major cause of coral mortality in tropical reefs worldwide. However, the complex nature of the holobiont has made it difficult to incontrovertibly identify a causative agent for most diseases. Certain bacterial species may have a direct role in inducing coral disease or making corals more vulnerable to environmental conditions, yet the functional consequences for corals of most bacterial species have not been determined.
Central focus: Studying the phylogeography and pathogenesis of an obligate intracellular coral parasite, "Ca. Aquarickettsia rohweri," within the bacterial order Rickettsiales. The presence of this parasite is correlated with decreased coral health as well as increased susceptibility to White Band Disease, and its growth is stimulated by an excess of nitrogen in the form of nutrient pollution. By probing the genome of this newly-discovered organism, I was able to discover genetic basis for these effects on coral health, which is primarily due to energy (ATP) and amino acid parasitism of the coral host. To study this in more depth, I conducted a nutrient-enriched tank experiment as part of our lab's partnership with Mote Marine Lab in Summerland Key, FL. I am currently conducting qPCR and 16S rRNA amplicon sequencing to study population dynamics of A. rohweri in response to nutrient treatment in two genotypes of Acropora cervicornis. I will additionally use transcriptomics to study the effects of this parasite on coral immune health.
Other projects: 3D modeling of reefs affected by naturally-occurring CO2 seeps in Papua New Guinea through my work with Tara Pacific. This project utilizes innovative data visualization methods to evaluate variation in the coral holobiont at local and regional scales throughout the South Pacific.