With the help of modern science, OzFish Unlimited, Australia's only fish conservation charity, is on a mission to find out if the Kangaroo River Perch is still surviving.
It was last recorded in the wild over 20 years ago.
The native fish is a relative of the Macquarie Perch from the Murray Darling Basin, but genetic analysis indicates it's a completely separate species and unique to the fresh waters of the Shoalhaven and Kangaroo Rivers.
The Kangaroo River Perch looks much like a Macquarie Perch - silvery to dark grey, sometimes with a mottled pattern, a prominent lateral mid-line and white-ish eye. The species is usually smaller. The main point of difference is distribution - but genetically they are vastly distinct.
OzFish together with NSW Department of Primary Industries, local Land Services and the University of Canberra will partner in the project.
If it isn't found, it will be one of Australia's first freshwater fish extinctions.
If it is, it will be offered the best protections which will include preserving its natural habitat and having it listed under state and national law as a threatened species.
OzFish recently launched a crowdfunding campaign to generate the resources needed to commence the research and it's already having local anglers contact them about possible catches and sightings they've had over the years in the area.
Craig Copeland, OzFish Founder and CEO is thrilled by the response from anglers and hopes more will come forward with information.
"We are really excited about the potential to rediscover a species that has been a part of The Shoalhaven River system for thousands of years," said Mr Copeland.
"We're looking to see if any anglers have seen it since it was last sighted. If so, they can get in touch with OzFish or log the sighting in the DPI Fisheries threatened species reporting tool.
OzFish are calling on the public to pledge a donation to reach a $20,000 target. They are hoping to set up a local Chapter in the Shoalhaven region.