Abstract
A significant portion of global microbial life thrives in a surface- or particle-associated biofilm lifestyle. Marine biofilms are ubiquitous in the global ocean, playing essential roles in elemental cycling, larval settlement, and pollutant degradation. Biofilms on artificial surfaces ('biofouling’), are associated with corrosion and invasive species transport, which has spurred the development of novel antifouling technologies; effectiveness of such technologies was examined in this dissertation research through collaborative work. In this dissertation, I leverage the biofouling-antifouling framework to study community ecology of marine biofilms in the coastal Western North Atlantic Ocean. Strong bacterial succession and persistent protistan and invertebrate groups were detected in undisturbed biofilms. Antifouling via UV-C irradiation disrupted biomass and communities, enabled identification of UV-C tolerant bacteria and eukaryotes and suggested increasing prevalence of UV-C tolerance with biofilm age. Application of “foul-release” paint and repeated pulse disturbance via underwater shear altered the community succession, and coating combined with infrequent shear was the most effective antifouling solution, enabling biomass removal with minimal enrichment of shear-tolerant taxa. In contrast, high-frequency shear resulted in the enrichment of shear-resistant taxa that potentially represent heightened invasion risk upon transport. Cross-domain correlation networks revealed eukaryote-bacterial associations that persisted through the disturbance continuum, highlighting strong connectivity of the diatom Melosira. Finally, the ecological stability of marine biofilms in response to shear was assessed. Overall, stability in marine biofilms was highly dimensional, requiring assessment of multiple stability properties. This study supports the growing body of evidence suggesting that following disturbance in natural and semi-natural systems, functional recovery is much more prevalent than compositional recovery. This research sheds light on the successional patterns, response to disturbances, and ecological stability of a key mode of microbial life in the global ocean.