New Southern Cross University research on pesticide runoff shows that widely used pesticides can affect shrimp and oysters.
Scientists at the National Marine Science Centre in Coffs Harbour on the North Coast of New South Wales have discovered that imidacloprid (approved for use as an insecticide, fungicide and parasiticide in Australia) may affect shrimp feeding behavior.
Centre director Kirsten Benkendorff (Kirsten Benkendorff) said that for seafood types, they are particularly concerned about how water-soluble pesticides affect shrimp.
She said: “They are closely related to insects, so we made an assumption that they might be very sensitive to pesticides. This is definitely what we found.”
A laboratory-based study showed that exposure to pesticides through contaminated water or feed may lead to nutritional deficiencies and reduced meat quality of black tiger prawns.
Professor Benkendorf said: “The environmental concentration we have detected is as high as 250 micrograms per liter, and the sublethal impact of shrimp and oysters is about 1 to 5 micrograms per liter.”
“Shrimp actually started to die at an environmental concentration of about 400 micrograms per liter.
“This is what we call LC50, which is a lethal dose of 50. You want 50% of the population to die there.”
But the researchers also found in another study that exposure to neonicotine may also weaken the immune system of Sydney oysters.
Professor Benkendorf said: “Therefore, at very low concentrations, the impact on shrimp is very serious, and oysters are more resistant than shrimp.”
“But we must have seen the impact on their immune system, which means they are likely to be susceptible to disease.”
Professor Benkendorf said: “From the point of view that they do absorb them from the environment, this is definitely something worthy of attention.”
She said that although further research is needed, it has found that it is necessary to effectively manage pesticide use and runoff in coastal areas.
Tricia Beatty, chief executive of the New South Wales Professional Fishermen Association, said that the study caused danger and the New South Wales government should take immediate action.
She said: “For many years, our industry has been saying that we are very concerned about the chemical impact of the upstream of the industry.”
“Our industry is worth A$500 million to the New South Wales economy, but not only that, we are also the backbone of many coastal communities.
“Australia needs to carefully study the ban on such chemicals in Europe and copy it here.”
Ms. Beatty said: “Not only on other crustaceans and molluscs, but also on the entire food chain; many species in our estuary eat those shrimps.”
Neonicotinoid pesticides-which have been banned in France and the EU since 2018-have been reviewed by the Australian Pesticide and Veterinary Drug Administration (APVMA).
APVMA stated that it started the review in 2019 after “evaluating new scientific information about environmental risks and ensuring that product safety claims meet contemporary standards.”
The proposed management decision is expected to be issued in April 2021, and then after three months of consultations before a final decision on the chemical is made.
Although researchers point out that berry growers are one of the main users of imidacloprid on the coast of Coffs, the peak of the industry has defended its use of this chemical.
Rachel Mackenzie, executive director of the Australian Berry Company, said the widespread use of this chemical must be recognized.
She said: “It is located in Baygon, and people can control their dogs with fleas. It is widely used for newly developed termite control; this is not a big problem.”
“Second, the research was conducted in the laboratory under laboratory conditions. Obviously, they are very preliminary.
“Let us stay away from the fact of this berry industry and consider the fact that this product has more than 300 uses registered in Australia.”
Ms. Mackenzie said that the industry will 100% comply with APVMA’s review conclusions on neonicotinoids.
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