Award: OCE-1938112

Collaborative Research: Quantifying Coral Microbiome Dynamics Under Change There is speculation that the coral microbiome, including a community of bacteria and archaea that live in the mucous surrounding the animal, may provide added resistance and resilience to corals facing pathogens and warmer ocean conditions. Our ability to assess such concepts is limited because there are no quantitative methods available to track specific microbial lineages within coral microbiomes. Our experiments across healthy, non-stressed and ecologically and phylogenetically diverse coral species allow us to measure and track specific microbial lineages within the coral microbiome. Our initial experimental design included examining microbiome dynamics under scenarios of thermal stress, reef environmental change, and disease development. Due to COVID 19 restrictions, experiments in Little Cayman to evaluate reefs with contrasting temperature and other environmental properties were postponed. However, our collaborative team from WHOI traveled to Little Cayman in mid-2022 to develop a site and logistical plan for a new coral transplant experiment that involves mesophotic (deep) and shallow corals. Successful field efforts in the USVI during summer 2021 made it possible to examine changes in the coral microbiome following reef-site based exposures from reciprocal transplantation experiments between two reef sites off the north side of St. Croix. After 6 months of transplantation, 5 coral species: Acropora cervicornis, Porites porites, Pseudodiploria strigosa, Orbicella annularis, and Orbicella faveolate were recovered and buoyant weight and photosynthetic efficiency of the colonies were measured. Samples were frozen and transported back to Woods Hole where the group is working to quantitatively assess changes in the coral microbiome to improve our understanding of factors that lead to coral resilience and resistance to disease and temperature stress. Three graduate students and a post-doc received field and laboratory training on this project. Two talks, one in person and one virtual, were given by project members that described aspects of the project. A manuscript describing a reef seawater meta-analysis was published in Aquatic Microbial Ecology. More broadly, microbial communities (or microbiomes) are features of all living systems on Earth. The methodological improvements to quantify the coral microbiome developed in this project will be directly useable by other disciplines. For example, these methods have the potential to improve quantitative examination of microbiomes in agriculture and fisheries and can also be used to better understand and predict how climate change impacts host-associated microbiomes. Last Modified: 01/12/2023 Submitted by: Carrie Manfrino