How Healthy is the Habitat?
Background
The Werribee River starts as a small river in the Wombat State Forest and flows south-east through Ballan, Werribee Gorge and Bacchus Marsh, where it meets the Lerderderg River. The River continues until its waters are held back by the Exford Weir creating the Melton Reservoir. The river becomes tidal at the Werribee Park Mansion, continuing to flow gently to Port Philip Bay. This completes a journey of approximately 110 kilometres.
Significant flora and fauna species exist within the catchment, however many of the species are threatened by weed invasion, predation by vermin, pollution and over-grazing. Many of the fauna species that were once found in the region are now classified as endangered or extinct.
In 2021, the Victorian Government listed the platypus as vulnerable in Victoria. In Melbourne catchments, 10 distinct platypus populations have been identified, the Werribee Gorge being one of them. The Government is taking action to protect the species. The project named Protecting Our Precious Platypus involves platypus surveys to determine the presence and absence of the species in waterways, and to determine how threats like climate change, water availability and quality, riverbank condition and foxes and other predators can affect platypus populations.
One monitoring method for platypus is the use of environmental DNA (eDNA). Small traces of DNA from animals in the water (e.g. hair, mucous, skin, faeces), can be analysed from water samples to identify the presence of the species. This provides a broad estimated of their abundance.
Key Learning Question
What evidence suggests the Werribee Gorge is able to sustain a platypus population?
Learning Intentions
In this activity students will:
- Define ecosystem, biodiversity, habitat assessment, biological and chemical testing, environmental DNA (eDNA)
- Determine the habitat requirements of the platypus and the location of platypus populations
- Conduct field work to assess river habitat and quality
- Evaluate ‘how healthy is the habitat’ for the platypus
Activities
The day is outlined below:
| 10am-10.30am | Ecolinc – identify the features of the platypus, habitat requirements, threats and historical data from Werribee Catchment |
| 10.30am – 10.45am | Travel to the Werribee Gorge |
| 10.45am – 11.00am | Walk to the Werribee Gorge from the car park |
| 11.15am – 2.15pm | Fieldwork: collect eDNA sample, habitat assessment, sample macroinvertebrates and water quality testing (including 30 minute lunch) |
| 2.15pm – 2.30pm |
Conclusion: 'How healthy is the habitat for the platypus?'
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- Maximum number of students for this program is 50 per day.
- This program is conducted at the Werribee Gorge. Your bus will need to arrive at Ecolinc at 10am, and the bus will need to stay onsite to transport students to the Werribee Gorge. The program will conclude at 2.30pm from the Werribee Gorge. Buses will need to stay onsite at Werribee Gorge for the duration of the program.
- Students will need to bring appropriate clothing according to the time of year and forecast. This includes solid footwear as well as sunscreen and hat (spring/summer), waterproof coat and hat (autumn & winter).
- This activity involves a walk of approximately 1km downhill/uphill to the field work site along the Werribee River. The road surface is gravel and uneven in sections. This walk could be challenging for students/staff with mobility issues.
Victorian Curriculum
Science – Biological sciences
- Ecosystems consist of communities of interdependent organisms and abiotic components of the environment; matter and energy flow through these systems (VCSSU121).
