A cocktail of pesticides has been found in oysters and water from one of the North Coast’s dominant rivers, Southern Cross University researchers have found.
Samples taken from the Richmond River estuary reveal 21 different pesticides, including a mix of herbicides, insecticides and fungicides. The findings are published in the journal Environmental Pollution.
‘This study is the most comprehensive investigation that has been undertaken into the pesticides entering our waterways from agricultural and urban run-off in northern NSW,” said senior author Professor Amanda Reichelt-Brushett.
‘We actually had to couch this publication in the context of our extremely limited background knowledge of pesticides in the Richmond River.’
The concentrations of several pesticides exceeded safe environmental guidelines, including atrazine and diuron that are banned overseas. Benomyl was also detected despite being banned in Australia.
The researchers found more pesticides in the oysters than in the surrounding water, with an average of nine different pesticides in single oyster samples.
‘Oysters accumulate contaminants because they filter large volumes of water when feeding,’ said co-author Professor Kirsten Benkendorff.
‘Many of these pesticides have no allowable residue limits in seafood, and could be quite risky to humans if consumed. We also don’t yet know the cumulative risk from exposure to multiple pesticides at once.’
The study investigated six sites within the lower estuary of the Richmond River: Emigrant Creek, Fishery Creek, North Creek, two locations at Empire Vale, and south Ballina.
The first three sites are sub-catchments with a variety of land uses, including natural vegetation, plant nurseries, cattle grazing, horticulture (eg macadamia nuts, coffee, bananas, avocados, and stone fruit), urban residential and small industries.
The other three sites along the eastern side of the Richmond River estuary receive run-off mostly from sugar cane farming.
These areas have drains for flood mitigation through the low-lying sugar cane fields.
The Australian Pesticide and Veterinary Medicine Authority (APVMA) regulates the use of individual pesticides.
The Australian Water Quality Guidelines provides guidelines for only some pesticides in
fresh and marine waters but guidelines specific to estuaries are not available. Furthermore, these guideline values are only relevant to single contaminant exposure rather than exposure to mixtures.
Yet the researchers found mixtures in every sample they tested.
‘Some interesting work on mixture exposure is being done in Queensland in catchments of the Great Barrier Reef and we might be able to build upon that for our future work,’ said Professor Reichelt-Brushett.
‘At present there is little accountability for the downstream impacts from land-based run-off.’
This study highlights the urgent need to manage diffuse source water pollution in the Richmond River.
Further research is required to establish the magnitude of pesticide contamination in other
estuaries with intensive agriculture and urban development.
Historically the Richmond River estuary was a prime oyster growing and harvest area. The oyster industry shut down in the 1970s due to QX disease outbreaks from poor water quality.
Only one oyster lease remains in operation, close to the mouth of the estuary where there is more oceanic exchange.
Unfortunately, this report comes as no surprise to many river users.
Well !
Is ANYBODY surprised ? I have personally measured, just the sulphuric acid run-off from the acid-sulfate soils of the Tuckean Swamp and Marom Creek area where it is calculated over ten tons of full-strength battery acid ( sulfuric Acid ) flows through just one flood-gate into the river above Ballina per Day.
There are huge areas of Macadamia plantations (arguably the most toxic land use after Blue Berries ), bananas and this is excelled by the run-off of the cocktail of toxic chemicals from the urban areas, which are truly frightening in their concentrations and volume.
I would never eat oysters, mud-crabs or prawns caught in the Ballina area.
Cheers, G”)
You should eat them anyway as they suck up natural toxins also. Never eat the meat of a meat eater.
And Councils keep spraying the roadsides with huge amounts of herbicide sometimes over spraying a much larger area than needed around roadside posts and barriers. If it was asbestos people would be up in arms but no one seems to think twice about these chemicals which are undoubtedly dangerous and with in some cases, no safe exposure limit
When we were little kids, we would chew the asbestos walls, eat lead paint chips, and breath the sweat smell of leaded petrol, and we all survived. My father would use roundup a lot, and ended up getting an associated cancer. Depends on who owns what, as to what is considered dangerous. If you have the moneyed power, you have the ‘science’.
You should be told Christian,
Asbestos and lead, like ’round up’ and many of the other toxic cocktails we are subjected to, do not kill immediately but are cumulative and the effects are life-long. The lead of which you seem to have an affinity, has the well-documented effect of lowering intelligence, inhibiting the ability to assimilate new information while increasing the propensity for violence and aggression. Sound familiar ?
Condolences on the death of your father, however the carcinogenic properties of glyphosate have been well known for at least fifty years and no amount of ‘money’ will change the science one iota.
Meanwhile, the old adage of “Never eat the meat of a meat eater.” may have some limited validity, but it does preclude all poultry and most fish, pigs, and even ungulates eat their afterbirths but more to the point it is the filter-feeders, crabs, prawns, oysters and molluscs as well as the top predators that are responsible for bio-accumulation ” as they suck up natural toxins” that can deliver doses many thousands of times the background concentrations of these, so-called ‘Necessary” deadly poisons.
Cheers, G”)
….and there’s nothing wrong with you!
No oysters? Let them eat caviar instead!
Those ‘poisons’ are necessary to make the bulk foods that the majority eat.
Piss poor reporting and 1/2 truths.3 year old report using sentinel oysters in known problem areas,no follow up, no oysters tested from an approved harvest lease while in open status.this type of sensationalism has ruined oyster sales at the one time when farmers can make a living to carry through until next year.
As we text here, thousands of cows are defecating and urinating, best case scenario at 10 meters from water catchments, no vegetation or native trees have been planted on the riperian areas, and massive Sugar cane and other industrial farming operations use the river as a dual chemical dump and watering system.
It is no secret that this farms with no trees act like a roof during heavy rain events and the entire towns have to suffer the effetcs of the pollution and the floods.
There is anyone at the wheel in any of all northern rivers councils.