. "Although Australia uses much lower levels of pesticides than other OECD countries, pesticide use is thought to have increased strongly here since the early 1980s.5 Cotton, rice, sugar cane and horticultural crops are the highest users of pesticides.5 Since 1990 at least 20 fish kills in New South Wales rivers have been attributed to pesticides.5 Other pollutants, such as heavy metals and oil, may" . . . .