Professor Possingham said tilapia were imported into Australia for the aquarium trade.
"It wasn't deliberate, it wasn't for food, it was an accidental introduction," he said.
"They seem to be inexorably spreading across subtropical and tropical Australia."
Professor Possingham said total eradication of tilapia in Queensland is impossible.
"Do we try and slow them down?" he asked.
"It would've made sense to find the southern edge of their range 10, 20 or 30 years ago and try and hold a boundary."
People still helping tilapia spread... http://www.abc.net.au/news/2016-08-12/t ... nd/7690180