Workers constructing a fish hotel in the Namadgi National Park. Photo: ACT Parks and Conservation Service, Facebook.
Australia’s freshwater fish are in trouble – and Canberra is right at the centre of the rescue mission.
A landmark study led by University of Canberra (UC) researcher Associate Professor Mark Lintermans found that 37 per cent of the nation’s native freshwater fish are now at risk of extinction, with some species predicted to vanish within just two decades.
“These figures are a wake-up call,” OzFish Program Manager Ryan Lungu said ahead of Canberra Fish Talks, a free public event being held on Thursday, 11 September, at the Belconnen Arts Centre.
“Native fish are struggling, hit hard by invasive species, altered river flows, habitat loss and now a changing climate. The Canberra Fish Talks are a chance to assist the community in taking positive actions to improve the habitat for native fish in our waterways.”
An OzFish forum in November 2023. Photo: OzFish.
Hosted by OzFish, Australia’s recreational fishing conservation charity, the event will bring together fishers, scientists and the wider community to swap stories, share knowledge, and learn how to restore fish habitats in local rivers and lakes.
For UC freshwater fish biologist Dr Ben Broadhurst, the numbers are confronting but not surprising.
“The fact that 37 per cent of native species are now at risk of extinction – with some predicted to disappear within the next 20 years – is deeply alarming, though sadly not unexpected for those of us working in freshwater ecology,” he told Region.
Mr Broadhurst has spent more than 20 years studying the endangered Macquarie perch, one of the ACT’s flagship species. Once widespread across south-eastern Australia, the fish has been hammered by habitat fragmentation, sedimentation and invasive species. But targeted recovery work is paying off.
In the Cotter River, large-scale “artificial habitats” have given Macquarie perch critical refuge from predators. Conservation efforts have also reconnected previously isolated populations, allowing the fish to expand their range from just 5 km of river to more than 25 km.
The Macquarie perch. Photo: ACT Government.
“Macquarie perch are symbolic of the challenges facing many of Australia’s freshwater fish species,” Mr Broadhurst said.
“Their recovery is a bit of a litmus test for how well we can reverse declines through science-based conservation and collaboration.”
The ACT Government’s aquatic ecologist, Matthew Beitzel, has seen the same story play out with other threatened species, including the Two-spined Blackfish. After the 2020 bushfires, helicopters were used to install “fish hotels” in scorched rivers to help kickstart recovery.
The fish hotel is open for business. Photo: ACT Parks and Conservation Service, Facebook.
These “high-rise habitats” provide a bed of rocks for the fish to make a nest about the silted riverbed, while insects for food are attracted to branches, rocks and debris on top.
“The ACT has four threatened fish species – Macquarie Perch, Two-spined Blackfish, Trout Cod and Silver Perch – as well as three threatened crayfish,” Mr Beitzel said.
“Common causes for their decline are habitat destruction, sedimentation, diverting water for human needs, historical overharvest, fire, climate change and introduced fish. Barriers such as dams and weirs, even road crossings, have resulted in further isolation and loss of populations”.
Despite the challenges, the local government says the ACT is performing strongly in threatened species management. Initiatives such as engineered log jams in the Murrumbidgee, new blackfish bungalows in Namadgi, and environmental flows have supported the recovery of local populations.
“The ACT’s Macquarie Perch population is one of the most secure and one of the few that is expanding,” a spokesperson said.
Both Mr Broadhurst and Mr Beitzel agree that conservation isn’t just a job for scientists and governments – the community has a vital role to play.
“Education is key,” Mr Broadhurst said.
“Freshwater fish are often overlooked in favour of more charismatic wildlife, but once you learn about their life cycles and behaviours, it’s hard not to be captivated. Passionate advocacy from the public can make a real difference.”
Even helicopters have been employed for the job. Photo: ACT Parks and Conservation Service, Facebook.
The ACT Government says Canberrans can help by keeping pollutants out of drains, disposing of fishing line responsibly, following catch-and-release rules, and joining local groups like Waterwatch.
For OzFish’s Ryan Lungu, that community involvement is exactly what Canberra Fish Talks is about.
“Fish habitat restoration is key to ensuring that the sport we love can be enjoyed by our children and grandchildren,” he said.
“This event is about giving fishers the tools, knowledge and inspiration to turn the tide.”
Canberra Fish Talks will be held at the Belconnen Arts Centre on Thursday, 11 September, from 6 pm. The event is free and open to the public. Register online.
