The Werribee River is among the waterways that Melbourne Water’s platypus surveys will track for this spring’s breeding season.
Part of a three-decade-long monitoring program, the water authority recently completed a mapping project that combined catch and release methods with environmental DNA (eDNA) testing.
Involving collecting samples from over 1800 waterways in the Greater Melbourne area between 2021 and 2023, mucus, urine, feaces, skin and saliva shed by platypuses allowed ecologists to detect their presence weeks after they have been present.
Melbourne water waterways and wetlands research manager Dr Rhys Coleman said the eDNA provided crucial insights into the presence of platypus in specific rivers and creeks.
“Climate change and increasing urbanisation are impacting platypus habitats, and we must seize every opportunity to protect our precious waterways to stabilise their numbers,” Dr Coleman said.
One of the biggest threats to platypus populations is the increased water runoff from hard surfaces such as roofs, driveways, and roads into storm water drains that introduce contaminants and destroy their habitats.
Increasing urbanisation also poses the risk of more litter infiltrating waterways, of which can see platypuses die through entanglement.
Field work conducted by Ecology Australia has shown promise for platypus in the Werribee River, especially in the upper Werribee.
In the lower Werribee, a single male platypus was recaptured after being first identified in 2022, while the upper Werribee survey captured six new platypuses —four males and two females.
A notable observation was the capturing of a male and female pair in the same net on two different occasions, offering speculative hope at potential breeding in the area.
Residents can play their part in protecting platypuses in the Werribee River through measures such as monitoring their waste, reporting platypus sightings via the Platypus Spot app, joining a local Waterwatch group, and participating in planting and litter clean up initiatives.
Jaidyn Kennedy