Exploring the toxicity of ‘alternate’ pesticides on the Great Barrier Reef

Over 50 different pesticides can be detected in the waters of the Great Barrier Reef (GBR), yet most research is directed at only five Photosystem-II (PSII) chemicals. The purpose of Project 3.1.5 was to fill knowledge gaps to improve national water quality guideline values for these other pesticides using partnerships between researchers and the Queensland Department of Environment Science’s Water Quality and Investigation Team. The results showed that most of these alternate pesticides had lower levels of toxicity than the five main PSII herbicides (including the common herbicide diuron), some non-PSII herbicides such as isoxaflutole had similar toxicities to freshwater plants, while the fungicide chlorothalonil was found to be quite toxic to coral larvae. Reliable water quality guideline values for all pesticides detected in the GBR are needed to improve water quality monitoring, reporting and risk assessments for the GBR, its catchments and also nationally.


Photo: AIMS