Cellular traits regulate fluorescence-based light-response phenotypes of coral photosymbionts living .

Diversity across algal family Symbiodiniaceae contributes to the environmental resilience of certain coral species. Chlorophyll- fluorescence measurements are frequently used to determine symbiont health and resilience, but more work is needed to refine these tools and establish how they relate to underlying cellular traits. We examined trait diversity in symbionts from the generas and collected from 12 aquacultured coral species.

Coral physiology and microbiome dynamics under combined warming and ocean acidification.

Rising seawater temperature and ocean acidification threaten the survival of coral reefs. The relationship between coral physiology and its microbiome may reveal why some corals are more resilient to these global change conditions. Here, we conducted the first experiment to simultaneously investigate changes in the coral microbiome and coral physiology in response to the dual stress of elevated seawater temperature and ocean acidification expected by the end of this century.

Microelectrode characterization of coral daytime interior pH and carbonate chemistry.

Reliably predicting how coral calcification may respond to ocean acidification and warming depends on our understanding of coral calcification mechanisms. However, the concentration and speciation of dissolved inorganic carbon (DIC) inside corals remain unclear, as only pH has been measured while a necessary second parameter to constrain carbonate chemistry has been missing. Here we report the first carbonate ion concentration ([CO3(2-)]) measurements together with pH inside corals during the light period.

Coral energy reserves and calcification in a high-CO2 world at two temperatures.

Rising atmospheric CO2 concentrations threaten coral reefs globally by causing ocean acidification (OA) and warming. Yet, the combined effects of elevated pCO2 and temperature on coral physiology and resilience remain poorly understood. While coral calcification and energy reserves are important health indicators, no studies to date have measured energy reserve pools (i.