Fish kill near Lightning Ridge

On a recent trip to Lightning Ridge we found a recently flooded creek had caused Billabongs to form trapping fish in receding waters with a resultant immense fish kill. These fish, mostly Carp,were trapped in warm stagnant water. With nowhere to go. The smell was terrible and the survivors were forced to swim on their side as the water was so shallow. Definitely not a pretty sight. Highlighted the fact these introduced fish are incredibly plentiful and in most Australian rivers, doing an enormous amount of damage to the local native fish species and the river habitat in general. How do we eradicate them? Any ideas?