The role of irradiance and C-use strategies in tropical macroalgae photosynthetic response to ocean acidification.

ABSTRACT: Fleshy macroalgae may increase photosynthesis with greater CO₂ availability under ocean acidification (OA) and outcompete calcifying macroalgae important for tropical reef accretion. Macroalgae use energy-dependent carbon concentrating mechanisms (CCMs) to take up HCO₃^-, the dominant inorganic carbon for marine photosynthesis, but carbon-use strategies may depend on the pCO₂, pH and irradiance. We examined photosynthesis in eight tropical macroalgae across a range of irradiances (0-1200 μmol photon m^-2 s^-1), pH levels (7.5-8.5) and CO₂ concentrations (3-43 μmol kg^-1). Species-specific CCM strategies were assessed using inhibitors and δ¹³C isotope signatures. Our results indicate that the log

SUBMITTER: Zweng RC 

PROVIDER: S-EPMC6013460 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature