Microbial Diversity and Physicochemical Niches in Coral Skeletons

Reef-building corals create large and complex structures that support the most biodiverse ocean ecosystems. Their success in nutrient-poor waters is attributed to interactions between the coral host and microbial partners from all domains of life, collectively known as the coral holobiont. Endolithic micro- and macro-organisms are common inhabitants of coral skeletons that comprise a large percentage of the total coral holobiont in terms of biomass and surface area. However, little is known about their role in coral physiology. Some of these microbes may contribute to skeletal dissolution, whereas others may promote calcification at the microscale or even provide carbon to the coral host during periods of stress.

Researchers at MBL are using Astrangia poculata, a local coral species, as a model system to better understand the roles of endolithic microbes in coral physiology and to how these microbial communities respond to change. This summer internship would focus on Astrangia poculata samples collected in 2023 at different locations around Woods Hole, and the student would be involved in preparing these samples for DNA extraction and sequencing of microbial communities. As sequencing will occur in-house at the Marine Biological Laboratory’s Keck Sequencing Facility, the student will have the opportunity to participate in sample and library preparation.  The student would also perform experiments on Astrangia poculata at MBL’s Marine Resource Center using microsensors and microprobes. These experiments would help to characterize the physicochemical environment within the skeleton of Astrangia poculata and provide insight into microbial activity.

Supervisor(s): Molly A. Moynihan, Loretta Roberson, Emil Ruff