Seaweed-coral competition in the field

A number of tropical reefs have transitioned from coral to macroalgaldominance, but the role of macroalgal competition in coral decline is debated.There is a need to understand the relative roles of direct coral-algal effectsversus indirect, microbially mediated, effects shaping these interactions, aswell as the relevant scales at which interactions operate under natural field,as opposed to laboratory, conditions. We conducted a manipulative fieldexperiment investigating how direct contact versus close proximity (approx.1.5 cm) macroalgae (Galaxaura rugosa, Sargassum polycystum) impactedthe growth, photosynthetic efficiency and prokaryotic microbiome of thecommon Indo-Pacific coral Acropora millepora.