Brown trout hatched at the Salmon Ponds on Tasmania’s Plenty River in 1864, the first in the Southern Hemisphere, and were let into the wild the next year, according to the state’s Inland Fisheries Service (IFS). Their descendants now hold most of the island’s rivers, and the Swan galaxias, a small native fish, lives on only in the few creeks they cannot reach.<\/p>\n\n\n\n
Some of those fish have now bred in new creeks. NRM South, a nonprofit that runs natural resource programs in southern Tasmania, said on June 18, 2026, that Swan galaxias moved into trout-free streams in 2023 are reproducing.<\/p>\n\n\n\n
“Seeing evidence of successful breeding in these translocated populations is a great sign that these fish are adapting well to their new habitats and that the recovery approach is working,” Rob Freeman, a fisheries scientist at the Inland Fisheries Service, said in NRM South’s media release.<\/p>\n\n\n\n
Freeman said the new populations matter beyond the creeks themselves. “For a species facing such significant threats, establishing self-sustaining populations in safer locations is critical to reducing extinction risk and preserving important genetic diversity for the species,” he said.<\/p>\n\n\n\n
The Swan galaxias was only discovered in 1978. Adults reach up to 5.3 inches (135 millimeters), according to the state’s Threatened Species Link, and live around three years. IFS wrote during its 2018 survey that “juvenile Swan galaxias tend to swim in open water. This makes them an easy meal for trout and other native fish.”<\/p>\n\n\n\n
What is left sits in headwater streams of the Swan River and Macquarie River catchments in eastern Tasmania, sometimes in just several hundred meters of water. NRM South blames the decline on “the increasing dispersal of invasive, predatory species, including trout and redfin perch,” along with the fragmentation and isolation of the fish’s preferred habitat.<\/p>\n\n\n\n
IFS dates that first hatch at the Salmon Ponds precisely, to May 4, 1864. Today the same agency stocks trout in Tasmanian waters and also runs native fish recovery, including the Swan galaxias work.<\/p>\n\n\n\n
Mark Lintermans, then an associate professor at the University of Canberra, led a 2020 national assessment of the country’s most endangered freshwater fish. IFS describes the Swan galaxias as “one of Australia’s 22 most threatened freshwater fish at imminent risk of extinction within the next 20 years.”<\/p>\n\n\n\n
Modeling in mid-2022 found around 1,200 possible sites. A desktop survey cut that to 84, IFS said, and after field visits and a look at future climate four were judged suitable, two of them highly suitable. Genetic work by CSIRO, Australia’s national science agency, guided which fish were picked.<\/p>\n\n\n\n
In March 2023 IFS moved 120 fish from four populations into two streams in the northeast. A later survey caught seven in one and one in the other. “This is a great result and while no obvious signs of breeding have occurred yet, all fish were in very healthy condition and the stream flows were good!” the agency wrote that December<\/a>.<\/p>\n\n\n\n Sixty more went into Devlins Creek in April 2025, and NRM South says that group already shows early signs of breeding. That brings the total moved into trout-free streams to 180 fish.<\/p>\n\n\n\n Headwaters keep the trout out but also dry up and flood. Five separate populations have been wiped out by droughts and floods since the early 1990s, NRM South says, a threat familiar to a fish left in stagnant pools in Spain’s summer rivers<\/a>.<\/p>\n\n\n\n To find fish without catching them, the group helped develop an environmental DNA marker, a test for the genetic traces animals leave in water. It “was able to detect Swan Galaxias DNA in a water sample, meaning that species presence could be confirmed without having to physically observe or capture an individual,” NRM South writes.<\/p>\n\n\n\n NRM South’s latest project only studied in-stream “anti jump barriers” to stop invasive fish moving upstream. On the Colorado River, managers took another route by cooling water below Glen Canyon Dam to stop invasive fish<\/a>. In Tasmania, the group notes, “previous attempts to undertake captive breeding of Swan Galaxias and carry out invasive species management within its habitat have both thus far been unsuccessful.”<\/p>\n\n\n\n Late in 2025, NRM South and IFS released short videos urging trout anglers to clean their gear and not move fish between waterways, the same drill used against hitchhikers like the quagga mussels now found in Northern Ireland<\/a>.<\/p>\n\n\n\n NRM South has not published how many juveniles were found. The project, paid for with $443,515 (Australian) from the federal Saving Native Species program, has ended, and IFS will keep monitoring.<\/p>\n\n\n\n The main source is NRM South’s media release, published June 18, 2026, on the NRM South website<\/a>.<\/p>\n\n\n\n “This project has demonstrated the importance of targeted conservation action and the real difference it can make to protecting our most at-risk populations,” NRM South CEO Nepelle Crane said in the release.<\/p>\n\n\n\n Photo: NRM South<\/p>\n","protected":false},"excerpt":{"rendered":" Brown trout hatched at the Salmon Ponds on Tasmania’s Plenty River in 1864, the first in the Southern Hemisphere, and … <\/p>\nNo count of young fish yet<\/h2>\n\n\n\n