Figure 2.

Summary of biofilm impact on the host varying from detrimental to beneficial effects according to the epibiont’s identity, the type of interaction considered and the environmental conditions. Via a recruitment/detachment equilibrium – controlled by environmental and host traits – epibiotic bacterial communities are connected to the free water phase. When forming a biofilm, bacteria experience a boost in activity and interactions. The host will experience a certain reduction in irradiation. Fouling, infections and predation will be affected by the presence of a biofilm, but extent and even sign of these effects are context-specific. An algal host will experience a reduction or an enhancement in nutrient availability depending on whether the autotrophic, respectively heterotrophic components prevail in the biofilm. Wastes and secondary metabolites (including infochemicals) may be metabilized by the biofilm.