Mr Alexander McGrath1,2, Prof. Peter D. Steinberg2,3,4, Dr. Sebastian V. Gonzalez1,2, AProf. Suhelen Egan2,3, Prof Staffan Kjelleberg3,4, Dr Ezequiel M. Marzinelli1,2,4
1School of Life and Environmental Science, The University Of Sydney, Sydney, Australia, 2Sydney Institute of Marine Science, Sydney, Australia, 3Centre for Marine Science and Innovation, School of Biological, Earth, and Environmental Science, University of New South Wales, , Sydney, Australia, 4Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, , Singapore, Republic of Singapore
Extreme environmental events are driving unprecedented ecological changes globally. In the marine realm, extreme events can be exacerbated along coastal habitats because of the concentration of human activities. We asked whether the microbial communities associated with Hormosira banksii, a dominant habitat forming seaweed, could mitigate the potential stress due to extreme rainfall. We monitored H. banksii’s reproductive output and performance prior, during and after an extreme rainfall event. Furthermore, we used manipulative experiments utilising a combination of antimicrobial treatments applied once (pulse) or regularly (press) to allow us to examine the role of Hormosira’s microbiota in influencing its response to rainfall. Rainfall induced stress had a significant negative effect on host reproductive output and photosynthetic yield. Furthermore, experimental manipulation following rain inhibited the recovery of both the reproductive output and photosynthetic efficiency of the host for over a month. When the host’s microbiome was repeatedly disrupted (press), the host did not recover either reproductive output or photosynthetic function for over four months. This experiment demonstrates the role host-associated microbiota play in mediating responses of important habitat forming algae and allows us to better understand how these ecosystems will respond to future environmental change.
Presentation Slides – Alexander McGrath
