SRA

Field and laboratory assessments were completed on the Hunter River estuary, New South Wales (NSW), Australia, to understand the ecological implications of point-source wastewater discharges in the estuary. This sampling targeted pelagic microbial communities to understand the biological change of organisms and the health of the community, in terms of their ability to cycle nutrients and organic matter. Whole Effluent Toxicity (WET) testing was also completed to better understand effluent toxicity on estuarine microbial communities at a more practical scale. The WET testing was designed to highlight the effects of mixing treated effluent within freshwater and saltwater environments, and to identify potential tipping points that both inhibit and stimulate the growth of microalgae and microbial communities. All water samples were sequenced for 16S and 18S rRNA genes to measure changes in community structure. Flow cytometry was used to enumerate chlorophyll-a and heterotrophic bacterial cells, and to estimate their size. The abundance of genes associated with nutrient cycling, antibiotic resistance and the identification of pathogens that would be harmful to human health were determined using micro-fluidics quantitative polymerase-chain reactions (MFQPCR) at the microbial community-level.