Matthew Higgins has been on the NSW Far South Coast since August studying Australia's the platypus.
He's been focused on the Bega River and has come up trumps.
"I have seen about 11 to 12 platypus in total, they disappeared for a time after the floods in February," Mr Higgins said.
The discovery is a positive sign for the region.
"It indicates that local biodiversity is perhaps stronger than we thought," Mr Higgins said.
"To watch platypus you need to be quiet and watch the water surface carefully.
"Watch for the animal to rise in order to breathe, before diving again to the bottom to continue feeding."
The platypus is one of two the monotremes (egg-laying mammals) in Australia, the other the echidna.
"They have incredibly sensitive bills which enable them to find their prey on the stream bed, they make burrows in the stream bank, and the female's nesting burrow can be up to 20m long," Mr Higgins said.
Habitat degradation and foxes are threats two key threats to the species, Mr Higgins said.