CHOMPIN - Coral Health On Moorea Parrotfish and Inorganic Nutrients

Project CHOMPIN was developed to further investigate a finding from project HERBVRE. Parrotfish, reef herbivores, often predate corals to supplement their diet. While parrotfish predation causes some tissue damage, total colony mortality rarely occurs. However, in project HERBVRE our team found that in waters enriched with nitrogen and phosphorous, coral mortality increased from 0% to ~65% in Porites colonies following parrotfish predation. We hypothesize that nutrient exposure and predation interact to cause two major changes to the coral holobiont, reduced host immunity and the proliferation of pathogens, which combined lead to coral death. This project therefore seeks to identify the microbiome-dependent route to coral death in nutrient-mediated predation mortality.

Experiments will be conducted on the reef and in saltwater tanks at the Gump Research Station on Moorea, French Polynesia. We will conduct nested experiments with nutrient treatments, predator exclosures, and antibiotic treatments. Throughout the experiment, we will track the changes in coral-associated bacterial communities and Symbiodinium and changes in the host genome. We will use bioinformatics and statistical pipelines to analyze changes in the structure and function of microbial communities and holobiont gene expression patterns such as innate immune responses.

For more information, contact PhD student Becca Maher. Becca will be conducting the field experiments and microbial analyses in collaboration with Mallory Rice in the Burkepile Lab at UC Santa Barbara.

Figure from Zaneveld et al. 2016, Nature Communications: 10.1038/ncomms11833