Shoalhaven River platypus population under threat

The platypus population in the Shoalhaven River is under threat as low water levels impact the beloved Australian icon. A new study has shown that platypus numbers across the country have almost halved due to drought, land clearing and fragmentation.

A representative from the Queanbeyan Palerang Regional Council (QPRC) said the Shoalhaven River had stopped flowing and that only ponds and pools remained.

QPRC said low water levels could impact the water quality of remaining ponds and pools.

"This in turn can impact food sources for platypus and other local wildlife," they said.

The council stopped pumping from the river for the Braidwood water supply on January 10 and has introduced level four water restrictions for the region.

"Council is very conscious of the need to retain enough water in the remaining ponds and pools for platypus and other ecology. We have committed to doing so and have ceased pumping water from the river to ensure adequate supplies for the wildlife," the spokesperson said.

Alarmingly, the UNSW study estimated that platypus numbers had almost halved, leading to the extinction of local populations across about 40 per cent of the species' range, reflecting ongoing declines since European colonisation.

Published this month, the study examined the potentially devastating combination of threats to platypus populations, including water resource development, land clearing, climate change and increasingly severe periods of drought.

Lead author and researcher Dr Gilad Bino said action must be taken now to prevent the platypus from disappearing from waterways.

"There is an urgent need for a national risk assessment for the platypus to assess its conservation status, evaluate risks and impacts, and prioritise management in order to minimise any risk of extinction," Dr Bino said.

To address population decline on a local level the QPRC established a platypus monitoring program where they ask the community to report sightings of the monotreme.

The council said in rural and remote areas they did not receive many reports, however they did have knowledge of at least two platypus sightings in the past 12 months.

"One local resident recently sent us photos of a platypus in the river on January 11.

"We also see many comments from local residents that they often see platypus in Gillamatong Creek."

The study predicted that under climate change, the losses forecast were far greater because of increases in extreme drought frequencies and duration, such as the current dry spell.

"These dangers further expose the platypus to even worse local extinctions with no capacity to repopulate areas," Dr Bino said.

To address low water levels in Braidwood additional water will be sourced from both the Bungendore and Queanbeyan water supplies. The water will be trucked to Braidwood and added to the supply.

To address long term water issues the QPRC has undertaken preliminary investigations into potential groundwater sources in the area but they are not expected to be available during this spell of dry weather.

"While the current off-river storage dam has served Braidwood well, we'll also look at additional sources and off river storage options in the future," the spokesperson said.

Dr Bino said the researchers' paper added to the increasing body of evidence which showed that the platypus, like many other native Australian species, was on the path to extinction.

"There is an urgent need to implement national conservation efforts for this unique mammal and other species by increasing monitoring, tracking trends, mitigating threats, and protecting and improving management of freshwater habitats," Dr Bino said.