Warm salty water is forcing an unlikely migration in Lake Ellesmere.
Thousands of rogue goldfish are swimming up rivers that drain into the lake in search of cooler, less briny water, and locals say they've never seen it before.
The fish have been hiding under logs and trees for days, swapping the warmer salty waters of Lake Ellesmere for the cooler clearer water upstream.
“We are not too sure what type of fish they are,” says fisherman Andre Brocherie.
Locals think they are carp, while Fish and Game reckon they are goldfish.
“They have probably been put there by letting fish out of their goldfish pond, and then they have just multiplied and enjoyed the conditions,” says Fish and Game officer Steve Terry.
The Lower Selwyn River is a popular trout fishing spot, but locals say the rogue fish are having an affect on the river.
“They are starting to kill off all the eels and all the weed and the egnungas,” says Mr Brocherie.
But Fish and Game say goldfish aren't their problem.
“They are not actually a sports fish. You can catch as many as you want and use any method you want to catch them,” says Mr Terry.
If you are fast enough you can even catch them with your bare hands.