1991 Darling River cyanobacterial bloom

The 1991 Darling River cyanobacterial bloom is the largest algal bloom on record, of the Barwon-Darling River in New South Wales, Australia. Parts of the river were sprayed with a Copper based algaecide using a crop duster.

Source: Wikipedia — 1991 Darling River cyanobacterial bloom (CC BY-SA 4.0)