1991/2 – Records of Fish Kills in Inland Waters of NSW and Qld in Relation to Cotton Pesticides. Fish kills associated with insecticide Endosulfan used primarily on cotton crops. Endosulfan recorded in Barwon River at Mungindi at 0.3ug/L. Source: Wetlands Australia 1998. A farmer was also prosecuted in 1989 for polluting the Barwon River at Mungindi with Endosulfan.