Recovery patterns of the coral microbiome after relief of algal contact

Interactions between macroalgae and corals are omnipresent on eutrophied overfished reefs worldwide. Contact with can disrupt their microbiomes through diverse mechanisms, including shading, abrasion, the release of algal exudates. However, changes in coral microbiome after contact ceases have not been studied. We investigated recovery massive reef-building Porites following experimental removal overgrowing green macroalga Halimeda macrophysa. followed macroalgal-removed adjacent healthy-looking tissue colonies over 40 days. Coral was predominantly bleached underneath but regained almost its full pigmentation by day 40. Despite this pigmentation, bacterial did return to that (control). Overall, macroalgal led suppression Gammaproteobacteria increased diversity dominance Alphaproteobacteria, a shift persevered for days removal. Causal effect analysis showed positive influential OTUs assigned Bacteroidia relative abundance other within these classes. The Alphaproteobacteria more diverse. high heterogeneity microbiomes, differences main classes orders control/healthy temporal patterns. Differences Alpha-, Gamma-, Deltaproteobacteria cessation stabilized or declined towards Acidimicrobiia, Deltaproteobacteria, Rhodospirillales Rhodovibrionales returned average abundances Nevertheless, Rhizobiales Rhodobacterales (Alphaproteobacteria) still dominated conclude overgrowth induces microbiome, lead Return distinct shifts groups time appear possible pathway