Australian Pesticides Map

A WATER QUALITY ISSUES ANALYSIS FOR THE JOHNSTONE RIVER BASIN

Report No. 11/05

for Terrain NRM

Stephen Lewis and Jon Brodie

Australian Centre for Tropical Freshwater Research, James Cook University

Final report April 2011

Agrochemicals

Herbicides

… Diuron, atrazine, hexazinone and tebuthiuron residues were detected in ‘grab’ samples collected along a transect from the Johnstone River to Russell Island (Kapernick et al., 2006). While herbicide residues detected were at relatively low levels (~5 ng/L diuron; others at 1-2 ng/L) compared to guidelines and effect concentrations, this sampling was conducted 2 weeks after Tropical Cyclone Larry had crossed the coast and so concentrations may have been much higher in the earlier stages of the plume.

2006: Johnstone River Qld (offshore). Pesticides: Diuron, Atrazine, Hexazinone, Tebuthiuron

A WATER QUALITY ISSUES ANALYSIS FOR THE JOHNSTONE RIVER BASIN

Report No. 11/05

for Terrain NRM

Stephen Lewis and Jon Brodie

Australian Centre for Tropical Freshwater Research, James Cook University

Final report April 2011

Agrochemicals

Herbicides

… Diuron, atrazine, hexazinone and tebuthiuron residues were detected in ‘grab’ samples collected along a transect from the Johnstone River to Russell Island (Kapernick et al., 2006). While herbicide residues detected were at relatively low levels (~5 ng/L diuron; others at 1-2 ng/L) compared to guidelines and effect concentrations, this sampling was conducted 2 weeks after Tropical Cyclone Larry had crossed the coast and so concentrations may have been much higher in the earlier stages of the plume.