Great Barrier Reef: scientists find high levels of pesticides and blast chemical regulator


More than 50 individual pesticide residues have been detected in Great Barrier Reef waterways.

Leading marine scientists have detailed a litany of “serious deficiencies” by Australia’s chemical regulator that have failed to prevent the ongoing pollution of the Great Barrier Reef catchment, where they found excessive levels of several pesticides banned by other countries.A new paper, co-authored by reef water quality expert Jon Brodie and fisheries veterinarian Matt Landos, found that pesticide regulation and management in the reef catchment areas of Queensland had failed to prevent the exposure of ecosystems to the significant risk of agricultural chemicals.

The report detailed extensive concerns about the processes a practices of Australian Pesticides and Veterinary Medicine Authority (the APVMA), which is responsible for the regulation and licensing of chemicals. “More than 80 of the active ingredients registered for use in Australia are prohibited by the 27 member countries of the European Union,” the study says. “This includes 17 pesticides that are known to be or likely or probable to be carcinogens and 48 pesticides flagged as potential endocrine [hormone] disruptors.“More than 20 are classified as either extremely or highly hazardous by the World Health Organisation. Three of the pesticides are subject to actions by international conventions but are still used in Australia.”

Among the pesticides the scientists show were detected in the reef catchment is Atrazine, a herbicide banned in 60 countries due to concerns about water contamination but registered for use in Australia. The study documented how more than 50 individual pesticide residues had been detected in Great Barrier Reef waterways, and how the highest concentrations were in freshwater areas adjacent to areas of intensive cropping.

“Where monitoring exists in waterways (and little systematic monitoring of residues in waterways occurs in Australia), pesticide residues are detected widely and at concentrations often above Australian guidelines (where guidelines exist), and commonly above published effect levels, especially in intensive cropping situations,” the study said.“In the freshwater and estuarine reaches of Barratta Creek south of Townsville, with a catchment dominated by irrigated sugarcane cultivation and smaller areas of cotton and horticulture, a total of 43 pesticide residues were detected with seven pesticides exceeding ecologically relevant water quality guidelines/trigger values during the study period and four (including Atrazine) of these exceeding guidelines for several months.“Even far offshore in Great Barrier Reef marine waters pesticides are always found due to their surprisingly long half-lives in marine waters and long residence times in the Great Barrier Reef lagoon.”

The study detailed how the regulation and management by the APVMA had failed to prevent the exposure of ecosystems to chemicals, including the slow speed of regulatory reviews, which have in some cases dragged on for more than a decade. The authors’ concerns included that the regulator was focused on agricultural interests rather than environmental protection.“A major deficiency of the Australian regulatory system is that the APVMA is under the umbrella of the Department of Agriculture,” the study says. “This is unfortunate, because the priority of the Australian system is to provide chemicals for agricultural production, whereas protecting the environment is not a strong consideration.”Other concerns included the APVMA’s processes that support the ongoing use of registered products after environmental or health concerns are raised, rather than removing those products from use.“Australian law states that there must be conclusive scientific evidence that a pesticide is unsafe before it can be removed from use. Testing the effects of a pesticide on humans and the environment is a long and expensive process, so it’s unsurprising that Australia’s banned pesticides list is substantially shorter than most other countries which stipulate that a pesticide must be proven safe before it can be sold.

“The ad hoc, case-by-case and very slow chemical review process administered by APVMA has not effectively assessed or addressed chemical risks to the Great Barrier Reef, or elsewhere.”

The scientists found Australian water quality guidelines for pesticides were “badly out of date” and updates had been severely delayed.‘“A related issue is the long delays between strong evidence of exceedance of guidelines in waters over long periods, as demonstrated via published monitoring studies, and regulatory or management action.“To adequately protect the Great Barrier Reef, given its marine protected area and world heritage status, both the special management provisions for the area already existing plus an effective national pesticide regulatory regime at least of the standard of the European Union are the minimum requirements.

Continued detections of above guidelines concentrations of pesticides and the conclusion that most basins of the Great Barrier Reef do not meet the current risk target lead us to conclude that, in general, pesticide regulation and management is, and has been, unsuccessful in the region.”

The APVMA said in a statement it had not been provided with a copy of the journal article, nor were they approached by the authors of the article.“In Australia, we employ a weight-of-evidence, risk-based model to regulate pesticides. This model considers both the hazards posed by a product and the likely exposure of humans, animals and the environment to those hazards,” the authority said.“The APVMA only registers chemical products where the risks can be mitigated through specific application and safety instructions on the product label. It is then the responsibility of state and territory governments to control the use of these products.”

It said active constituents were assessed on the basis of their expected volume of use, expected exposure and the behaviour of any active constituents, and the potential harmful effects on wildlife and organisms.“This information helps to establish whether the risk to any of these organisms posed by the use of the product may be considered unacceptable or whether there are other concerns due to the behaviour of the substance in the environment.”