Effect of Ocean Acidification on the Coral Microbial Community

Abstract

An emerging environmental stress that can impact coral reefs worldwide is ocean acidification, a result of increasing atmospheric CO2 concentration. Surface seawater pH is 0.1 units lower than pre-industrial values and is predicted to decrease by up to 0.4 units by the end of the century. This change in pH may result in changes in the physiology of ocean organisms, in particular organisms that build their skeletons/shells from calcium carbonate, such as corals. This physiological change may also affect other members of the coral holobiont, which in turn may influence coral physiology and health. This chapter reviews the laboratory and field studies to date that have examined the effect of pH on the coral microbial community (i.e., bacteria, archaea, fungi, and endolithic communities). The impact of this change on the coral host is also discussed.