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
Chlorpyrifos and protiophos were the only insecticides detected in the passive samplers deployed in the North Johnstone River (Kapernick et al., 2007; Shaw et al., 2010). Chlorpyrifos is widely used in the sugar industry to control the greyback cane beetle/grub while protiophos is used in the banana industry (J. Armour, pers comm., 2009). The detection of chlorpyrifos in passive samplers is a concern given that this insecticide’s ANZECC and ARMCANZ (2000) guidelines for freshwaters (0.01 μg/L and 0.00004 μg/L for the 95% and 99% protection values, respectively – high reliability guideline) is within this detection range. The passive samplers accumulated 15 ng (or 0.015 μg) of chlorpyrifos over a 12 day deployment in the dry season (Shaw et al., 2010) meaning that >1 ng (>0.001 μg) must have been accumulated per day which could be within the range of the 99% protection guideline (although a conversion to a mean concentration was not performed). Unfortunately, no guideline has been developed to examine the toxicity of protiophos, although this insecticide is in the same chemical group as chlorpyrifos (organophosphate) and so it may also be of similar concern in the Johnstone Basin. Russell and Hales (1993) detected the insecticide residues DDE and dieldrin in oysters, mussels, mudcrabs, bony bream and catfish in the Johnstone River, although levels were thought to be of little concern. More recently, Negri et al. (2009) detected dieldrin and heptachlor in mudcrabs of the Johnstone River esturay….
Tebuconazole was the only fungicide detected in passive samplers deployed in the North Johnstone River (Kapernick et al., 2007). Tebuconazole is used in the banana industry. No guideline value is available to examine the potential toxicity of tebuconazole.