Dr Sebastian Vadillo Gonzalez1,2, Dr Georgina Wood1,2,4, Mrs. Regine Tiong Hui5, Dr Kimberly Lema2,3, Dr Mariana Mayer Pinto3, Dr Federico Lauro5, Prof Staffan Kjelleberg5, Dr Fabio Bulleri6, Prof Peter Steinberg1,3,5, Dr Ezequiel Marzinelli1,2,5
1Sydney Institute of Marine Science, Sydney, Australia, 2The University of Sydney, Sydney, Australia, 3The University of New South Wales, Sydney, Australia, 4Keele University, Keele, United Kingdom, 5Nanyang Technological University, Singapore, Singapore, 6Università di Pisa, Pisa, Italy
Microbial communities contribute significantly to the structure and function of marine ecosystems; however, little is known of their vulnerability and response to environmental disturbances, particularly on intertidal rocky shores. We used experimental field manipulations and 16S amplicon sequencing to determine the effects of macroalgal loss on the understorey bacterial communities. Beds of the fucoid Hormosira banksii were exposed to 5 levels of disturbance in replicate plots: 100% removal of Hormosira, removal of 50% of the individuals, no canopy removal, a procedural control that mimicked the removal process, but where no Hormosira was removed, and adjacent bare rock with no naturally occurring Hormosira. Canopy cover, bacterial communities and benthic macro-communities were monitored and sampled 4 times over a period of 1.5 years. Results show that Hormosira removal or reduction of canopy cover rapidly influenced changes in the understory bacterial diversity and composition. With time, Hormosira canopies in all disturbed plots recovered, but benthic bacterial communities remained largely distinct in plots with the highest level of disturbance from those in other treatments throughout the experiment. These results demonstrate that bacterial communities respond rapidly to environmental disturbances at small scales and that impacts can be long-lasting. Ecological disturbances and declines to macroalgal beds are occurring globally. A deeper understanding of the importance of the understory microbial biofilm in these systems is needed to further understand the potential cascading effects disturbance may have on the overall structure and functioning of intertidal rocky shores.
Presentation Slides – Sebastian Vadillo Gonzalez
Biography:
Dr. Sebastian Vadillo is a postdoctoral research associate at the Sydney Institute of Marine Sciences and an honorary affiliate of the University of Sydney. Sebastian obtained his Ph.D. at the University of New South Wales by researching the alternative of using intertidal macroinvertebrates for the bioremediation of contaminated sediments. Currently, his research focuses on the area of environmental marine and estuarine sciences, specifically on microbial ecology and the effects of human-derived stressors.
