Reef biofilms under chronic nutrient enrichment

At present, work on marine biofilms has primarily focused on host-associated habitats for their roles in larval recruitment and disease dynamics; little is known about the factors regulating the composition of reef environmental biofilms. To contrast the roles of succession, benthic communities, and nutrients in structuring marine biofilms, we surveyed bacteria communities in biofilms through a six-week succession in aquaria containing macroalgae, coral, or reef sand factorially crossed with three levels of continuous nutrient enrichment. We hypothesized that the organic resources derived from the surrounding benthic organisms and inorganic nutrient availability would work interactively and orthogonally to influence biofilm assembly and succession. Over the course of six weeks, we tested the effect of constituent benthic organisms (corals, algae, and sand-associated microphytobenthos) and sustained nutrient loads on the successional dynamics of developing marine biofilms on glass slides.