Description
Berry Springs Nature Park is an important recreational site in the Darwin region and offers the only natural swimming pools in the vicinity of urban Darwin. These pools are monitored using the common test for faecal contamination – enterococci. However, these bacteria also occur in wildlife faeces. When levels of enterococci exceed recreational water guidelines, the pools are closed. This happens sufficiently frequently to cause frustration to the public and leads to questions about where this ‘contamination’ is coming from. There is a justified view that if we know the source, we can manage bacteria levels. Since the test is not human faeces specific – it is not known whether or not this is a public health issue. Using human faecal specific tests in parallel with the standard test would allow greater clarity around the value of the standard test as an indicator of human faecal contamination.Our aim is to compare the contributions of different (potential) water sources (Berry Creek upstream of pools; Groundwater; Wildlife Park creek) to the pools from May to their closure in November. There will be 5 sampling rounds with 1 in May (before opening of pools), Sept (late dry season), 2 rainfall-related rounds in Oct/Nov and 1 event-based round such as after a sudden rise in enterococci numbers.
Analytical methods will include measuring stable water isotopes (incl. rainfall) and elemental ‘fingerprinting’ analysis by ICPMS aimed at quantifying ground-, soil- and surface water contributions to Berry Creek. Microbiology techniques will include molecular assays (qPCRs) to measure faecal indicators and total bacterial DNA levels and sequencing of the 16s rRNA genes to capture the whole bacterial community in water samples. 16s rRNA data will also be used for Bayesian source tracking to compare the bacterial contributions of each source to the bacteria in the pools. The standard enterococci tests will be performed to ensure historic and ongoing sampling programs are comparable.
| Period | 1 Sept 2018 → 31 Mar 2019 |
|---|---|
| Work for | Department of Environment and Natural Resources, Australia, Northern Territory |
| Degree of Recognition | Regional |