It's not been seen for more than half a century, but soon, visitors to the Royal National Park in Sydney will be able to spy some platypus in the riverways once again.
Classified as 'near threatened' by International Union for Conservation of Nature (IUCN), the species has been in decline for the past decade.
The wild population, it's believed, has fallen by 22 per cent in recent times, largely due to river mismanagement, habitat destruction, invasive species attack, as well as increased drought and fire events.
Platypus used to be seen in abundance across Sydney's national parks, but not since the 1970s has there been a recorded sighting.
Teams from Taronga Conservation Society, UNSW, the World Wildlife Fund (WWF) and NSW National Parks are now re-introducing a control group of 10 mating pairs into the waterways, in the hopes of jumpstarting the population once again.
"While platypus are resilient animals, we want to make sure future generations can see them in the rivers of the Royal and all the way down the east coast of Australia," said Professor Richard Kingsford from UNSW's Centre for Ecosystem Science.
"Platypus are hard to see and mainly nocturnal animals, so we will survey and assess the condition of all the rivers and creeks in the park and checking which part of the rivers are suitable for reintroducing new individuals."
The platypus will be fitted with acoustic tags so researchers can track their progress and any breeding activity for up to two years.
"Platypus are to our rivers what koalas are to our forests, but there's a risk they will disappear if we don't talk bold steps to reverse their decline," said Rob Brewster, WWF-Australia's Rewilding program manager.
Once the population has established successfully, NSW National Parks and Wildlife will begin constructing viewer platforms across the waterways so that visitors will be able to glimpse the goings on underwater.
"We are returning one of Australia's most iconic species to Australia's first and most iconic national parks," said Matt Kean, NSW Environment Minister.
"The platypus is seen nowhere else on the planet and like so many of our other iconic native species it's future is uncertain. Unfortunately, we have some of the worst extinction rates anywhere in the world and we have to make sure the platypus never makes that list."