A small native freshwater fish that is now only found in the upper reaches of the Hunter River is likely to be extinct within 20 years as a result of predatory trout that were introduced to improve recreational fishing, new research suggests.
Subscribe now for unlimited access.
$0/
(min cost $0)
or signup to continue reading
It is thought the Hunter galaxias would once have been among the most abundant fish species in Hunter River waterways. The fish is now only known to remain at six locations within the Hunter River catchment, in areas where there are no trout.
"One of the most important things we can do to prevent the extinction of this species is to not stock trout into the streams where the Hunter galaxias still occurs, or to any streams that connect to them. If trout reach them they are goners," Associate Professor Mark Lintermans from the University of Canberra, who has more than 35 years' experience in fisheries research and management, said.
The the Hunter galaxias is among 22 native freshwater fish that have been identified as likely to become extinct within the next 20 years, unless new conservation initiatives are introduced.
The fish study is part of a larger project by the National Environmental Science Program to identify species at high risk of extinction.
"Understanding which species are at risk is a vital first step in preventing their extinctions," Associate Professor Lintermans said.
The most at risk fish species in Australia is the Shaw galaxias in Gippsland Victoria.
A tiny fish with tiger stripes that has an 80 per cent chance of becoming extinct within twenty years if there is no change in management.
The species was once more wide spread, but there are now only around 80 remaining found in a single small population above a waterfall which protected them from trout.
"Most of the species we identified have had large reductions in their distributions, and now only occur in one small area.
This presents a new threat as a single catastrophic event, like a large bushfire, could potentially wipe out the species in one hit.
"These species were already imperilled before the 2019-20 fires, and many are now in even more dire straits," Associate Professor Lintermans said.
"For example, before the Black Summer fires we believed there were up to 2500 Yalmy galaxias, a species only found in the Snowy River National Park, which was badly impacted in the fires.
"Since the fires surveys have so far found only two individuals, one male and one female in separate areas. While there are plans to reunite them as soon as possible, the species is now extremely close to extinction.
"Invasive species, like trout, having only a single small population and climate change are the most common threats to the Australian fish species we identified as at greatest risk of extinction."
Associate Professor Lintermans said fish deserved more attention.
"Out of sight, under water, the decline of freshwater fish, especially our smaller native fish that aren't angling species, usually goes unnoticed," he said.
Matthew Kelly
Matthew Kelly has worked as a journalist for more than 25 years. He has been working as a general reporter at the Newcastle Herald since 2018. In recent years he has reported on subjects including environment, energy, water security, manufacturing and higher education. He has previously covered issues including the health and environmental impacts of uncovered coal wagons in the Hunter Valley, the pollution of legacy of former industrial sites and freedom of information issues.
Matthew Kelly has worked as a journalist for more than 25 years. He has been working as a general reporter at the Newcastle Herald since 2018. In recent years he has reported on subjects including environment, energy, water security, manufacturing and higher education. He has previously covered issues including the health and environmental impacts of uncovered coal wagons in the Hunter Valley, the pollution of legacy of former industrial sites and freedom of information issues.
