The upper Hawkesbury River in north-western Sydney is a mixed-use, peri-urban area facing particular challenges related to water quality. It is a crucial water source for domestic, agricultural, industrial, and recreational use. Intensification of human activity and population growth in this area has placed increasing pressure on the watershed and impaired the water quality, as indicated by high faecal coliform counts measured during our study. The aim of our study is to characterise the health of the catchment in terms of microbial communities, faecal indicators, and physicochemical water quality parameters.
This study profiles the microbial populations present in the water and sediment of the upper Hawkesbury River area using metagenomics and next-generation sequencing (NGS) techniques. The region was monitored over multiple seasons and sampled at various points upstream and downstream of agricultural and urban activities to draw out spatial and temporal patterns in the microbial populations.
The relationship between the bacterial communities, faecal contamination indicators, and physicochemical parameters was evaluated to determine any significant relationships. Preliminary results indicate variation in microbial diversity between sampled sites and time points and marked differences between bacterial communities present in the water column and the sediment.
The results from this study can be used to identify times, locations, anthropomorphic factors, and preceding environmental conditions that would increase the susceptibility of our water sources to microbial contamination, and thus affect public health and safety. It is a valuable case study for the complementary use of bacterial indicators and metagenomics to assess freshwater ecology and river health.