Project title: Microbial Threats in Coastal Environments
Supervisors: Prof. Justin Seymour, Dr Nahshon Siboni, Assoc. Prof. Maurizio Labbate.
Climate change is altering the biotic and abiotic structure of natural ecosystems but is having particularly significant impacts within coastal environments. These coastal ecosystems provide many ecological services that provide substantial economic benefits and food security. Like all aquatic environments, the productivity and health of coastal ecosystems are governed by the function of natural microbial assemblages, which are responsible for many ecological services such as forming the foundation of aquatic food webs, nutrient cycling and primary production. However, shifting environmental conditions, linked to climate change processes, are disrupting the natural balance of microbial communities, leading to detrimental consequences for ecosystem and human health. For instance, extreme weather events, including the increased frequency of coastal storms, are leading to an increased occurrence of stormwater runoff and coastal sewage overflows. In turn, this leads to the heightened input of enteric microbes, including pathogens, into coastal waters. Standard water quality monitoring approaches, using enumeration of faecal indicator bacteria, provide assessments of sewage contamination within the framework of international guidelines, but are incapable of discriminating the exact sources of microbial contaminants and fail to detect many dangerous pathogens. Additionally, increases in seawater temperature and marine heatwaves are stimulating blooms of harmful microorganisms, including bacteria within the Vibrio genus. Despite the potentially profound human health, economic and environmental impacts of these and other microbial perturbations, few studies have to date examined the likely impacts of climate change induced shifts in environmental conditions on the microbiology of coastal habitats. This project will directly examine how the composition and function of coastal microbial assemblages are changing and will continue to shift, under climate change scenarios, providing an important capacity for forecasting the future condition and influence of coastal ecosystems.
The first aim of this research is to characterise shifts in coastal microbial community structure spatially along the east coast of Australia during summer, with a specific focus on the abundance and virulence of pathogenic bacteria within the Vibrio genus. This research also aims to measure changes in coastal microbial assemblages after heavy rainfall events, with a focus on being able to identify the sources of faecal indicator bacteria in impacted coastal environments, with a principal goal of determining whether these bacteria are most likely sourced from sewage inputs or animals, such as dogs and birds. This research also aims to identify other microbial hazards that are missed by the current monitoring methods.
King, W. L., N. Siboni, N. L. R. Williams, T. Kahlke, K. V. Nguyen, C. Jenkins, M. Dove, W. O'Connor, J. R. Seymour and M. Labbate (2019). "Variability in the composition of Pacific Oyster microbiomes across oyster families exhibiting different levels of susceptibility to OsHV-1 μvar disease." Frontiers in microbiology 10: 473.