Native fish rescued after bushfires, rainfall and predators threaten their survival
There is hope two species of endangered native fish will survive in the wild, despite bushfires and damaging rainfall events in their habitat.
Both the stocky galaxias, rescued from the Tantangara Creek, and the Macquarie perch, in the Mannus Creek further west, were impacted by the huge Dunns Road blaze that burnt out more than 333,000 hectares in southern New South Wales before being brought under control.
Fish from both species were rescued in separate attempts in recent weeks.
Stocky galaxias are only found in a 4-kilomtre stretch of the Tantangara Creek, in Kosciuszko National Park, and are protected from predator trout by a waterfall.
National Parks and Wildlife Southern Ranges director, Mick Pettitt, said 140 of the critically endangered fish were rescued ahead of the fire impacting to create a captive insurance population.
"They capture the imagination here, these little fish, and they're only tiny," Mr Pettitt said.
"Putting efforts into something that doesn't exist anywhere else, potentially in the world, is all the more reason that we should be doing something and the reason that gives us the impetus to try and protect this little species that exists there."
The finger-sized fish were taken to a fish hatchery at Jindabyne, where there is hope they can be used to begin a breeding program and ensure the survival of the species.
The Department of Environment plans to fence off the small area of the creek from grazing animals to protect the wild fish from damage caused by grazing animals such as deer.
Survival against the odds
Further west, 10 Macquarie perch rescued by the NSW Department of Primary Industries are now in a tank at the DPI's Narrandera Fishery.
Fisheries manager Luke Pearce said it was the last population of the fish in the Murray system, and one of only four across the state.
The Dunns Road fire caused extensive damage in the Mannus Creek area in the Riverina Highlands of southern NSW.
"It had even burnt snags and logs that were in the middle of the creek and were lying in the creek — it was that hot in there," Mr Pearce said.
Mr Pearce said after rescuing nine fish, he returned last week to try to remove more.
But before he could, the effects of a rainfall event higher in the catchment washed down the creek.
"Basically when we got there we witnessed before our eyes the river turning from a normal flowing stream into basically a massive river of black porridge — it was just incredible," he said.
He said he had not expected any Macquarie perch to survive the blackwater event after finding dead aquatic life, but was shocked to discover some of the fish had survived despite the oxygen levels in the water plummeting to zero.
"There must be little pockets where they can sort of get away and find oxygen refuges, where there's enough oxygen in the water for them to survive," Mr Pearce said.
"Or they can hold their breath for a very long time."
He said the survival of the fish gave him hope for the broader region to recover from the fire.
"All the trees are shooting again … Green sprouts are coming up everywhere and the creek is starting to improve," Mr Pearce said.
"So it's not quite the same level of despair and devastation that it was previously, and it gives me real hope that we can maintain that population there and keep things going."