Convergent stochastic assembly governs reef biofilm microbiomes across ecologically distinct benthic substrates

A recent study has revealed that the assembly of reef biofilm bacteria on crustose coralline algae and calcium carbonate substrates is governed by similar processes, despite differences in diversity, composition, and environmental correlations. Researchers collected biofilm communities from 11 reef sites and sequenced the full 16S small subunit rRNA genes.

Both CCA- and carbonate-associated communities exhibited unique diversity patterns and were influenced by environmental conditions, but they were assembled through a common mechanism dominated by stochastic processes. Drift was the primary driver, with moderate effects from dispersal limitation and selection. Sub-communities of habitat generalists and specialists, along with rare and abundant taxa, had distinct assembly patterns that remained consistent across substrates, emphasizing the role of individual taxonomic traits.

These findings shed light on the factors that shape benthic biofilm bacterial assembly and biogeography in tropical reef ecosystems and contribute to understanding reef resilience in the face of environmental change.