AUTHOR=Yang Sung-Yin , Lu Chih-Ying , Tang Sen-Lin , Das Rocktim Ramen , Sakai Kazuhiko , Yamashiro Hideyuki , Yang Shan-Hua 

TITLE=Effects of Ocean Acidification on Coral Endolithic Bacterial Communities in Isopora palifera and Porites lobata

JOURNAL=Frontiers in Marine Science

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2020.603293

DOI=10.3389/fmars.2020.603293

ISSN=2296-7745

ABSTRACT=<p>Endolithic microbes in coral reefs may act as a nutrient source for their coral hosts. Increasing atmospheric CO<sub>2</sub> concentrations are causing ocean acidification (OA), which may affect marine organisms and ecosystems, especially calcifying organisms such as reef-building corals. However, knowledge of how OA affects marine microbes remains limited, and little research has been done on how coral endolithic communities respond to shifting environmental baselines. In this study, the endolithic communities of two common shallow water coral species, <italic>Isopora palifera</italic> and <italic>Porites lobata</italic>, were examined to investigate the microbial community dynamics under OA treatments. The colonies were placed in an environment with a partial pressure of carbon dioxide (<italic>p</italic>CO<sub>2</sub>) of 1,000 or 400 ppm (control) for 2 months. Several <italic>I. palifera</italic> colonies bleached and died at 1,000 ppm <italic>p</italic>CO<sub>2</sub>, but the <italic>P. lobata</italic> colonies remained unaffected. Inversely, the endolithic community in <italic>P. lobata</italic> skeletons showed significant changes after OA treatment, whereas no significant dynamics were observed among the <italic>I. palifera</italic> endoliths. Our findings suggest that the skeletal structures of different coral species may play a key role in corals host and endoliths under future high-OA scenarios.</p>