Coral thermal stress and bleaching enrich and restructure reef microbial communities via altered organic matter exudation.
Wesley J Sparagon, Milou G I Arts, Zachary A Quinlan, Linda Wegley Kelly, Irina Koester, Jacqueline Comstock, Jessica A Bullington, Craig A Carlson, Pieter C Dorrestein, Lihini I Aluwihare, Andreas F Haas, Craig E Nelson
Author Information
Wesley J Sparagon: Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, Honolulu, HI, 96822, USA. sparagon@hawaii.edu. ORCID
Milou G I Arts: Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, Texel, The Netherlands. ORCID
Zachary A Quinlan: Scripps Institution of Oceanography, University of California San Diego, La Jolla, USA.
Linda Wegley Kelly: Scripps Institution of Oceanography, University of California San Diego, La Jolla, USA.
Irina Koester: Scripps Institution of Oceanography, University of California San Diego, La Jolla, USA.
Jacqueline Comstock: Department of Ecology, Evolution and Marine Biology, The Marine Science Institute, University of California Santa Barbara, Santa Barbara, USA.
Jessica A Bullington: Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, Honolulu, HI, 96822, USA.
Craig A Carlson: Department of Ecology, Evolution and Marine Biology, The Marine Science Institute, University of California Santa Barbara, Santa Barbara, USA. ORCID
Pieter C Dorrestein: University of California San Diego, San Diego, USA.
Lihini I Aluwihare: Scripps Institution of Oceanography, University of California San Diego, La Jolla, USA.
Andreas F Haas: Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, Texel, The Netherlands.
Craig E Nelson: Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, Honolulu, HI, 96822, USA.
Coral bleaching is a well-documented and increasingly widespread phenomenon in reefs across the globe, yet there has been relatively little research on the implications for reef water column microbiology and biogeochemistry. A mesocosm heating experiment and bottle incubation compared how unbleached and bleached corals alter dissolved organic matter (DOM) exudation in response to thermal stress and subsequent effects on microbial growth and community structure in the water column. Thermal stress of healthy corals tripled DOM flux relative to ambient corals. DOM exudates from stressed corals (heated and/or previously bleached) were compositionally distinct from healthy corals and significantly increased growth of bacterioplankton, enriching copiotrophs and putative pathogens. Together these results demonstrate how the impacts of both short-term thermal stress and long-term bleaching may extend into the water column, with altered coral DOM exudation driving microbial feedbacks that influence how coral reefs respond to and recover from mass bleaching events.
