High hopes for platypus numbers

Wildlife ecologist Josh Griffiths completes a platypus population study in the Mackenzie Creek in 2015.

Wildlife ecologist Josh Griffiths completes a platypus population study in the Mackenzie Creek in 2015.

Platypus surveys this week will check on how last year’s flows have impacted a fragile platypus population in the MacKenzie River.

Wildlife ecologist Josh Griffiths from Melbourne-based environmental research company cesar will set survey nets for Wimmera Catchment Management Authority on Wednesday and Thursday night.

Wimmera Catchment Management Authority chief executive David Brennan said the authority had high hopes for finding platypus after a member of the public photographed one in the Grampians last month.

“We’re feeling very positive and it will be interesting to see whether there are any juveniles, which would indicate successful breeding,” he said.

The most recent Wimmera platypus surveys were in March last year, after the driest spring and summer on record.

Despite the dry conditions, last year’s surveys found the platypus population was holding its own.

Mr Brennan said rain last winter and spring provided welcome natural flows in the river, which had relied on environmental water releases to maintain the platypus habitat.

“We’re interested to see if the platypuses have started moving into the lower section of the river since last year’s rain provided such good natural flows,” Mr Brennan said. 

Mr Brennan said the surveys provided important data about the impact of environmental water releases.

“They help us ascertain the impact of these releases and are one type of monitoring that we do to track the MacKenzie River’s overall health,” he said.

Mr Griffiths will also take eDNA samples in sections of the river where previous trapping has failed to catch platypus.

This technology identifies the presence of different species from the DNA in waterways that comes from their skin, hair and urine.

He said since first introducing the technology for Wimmera platypus surveys in 2015, the potential of eDNA had exploded.

Wimmera CMA is also using the technology to track carp movement and yellowbelly and catfish populations in the Wimmera River.

  • Wimmera CMA will post updates on the Wimmera platypus surveys on their Facebook page. 
  • Environmental water releases in the MacKenzie River are prioritised as part of the Victorian Environmental Water Holder’s (VEWH) Seasonal Watering Plan 2016-17.