Weedkillers linked to even deadlier cane toads
THE cane toad is mutating into an even deadlier creature thanks to a common household weedkiller.
Toad tadpoles exposed to chemicals found in weedkiller Roundup have increased levels of bufadienolides – a toxic chemical used to ward off predators – as adults. The toad stores these toxins glands on its shoulders, in which it can use to deliver poisonous blasts at predators.
In a new study, Hungarian researchers said it could mean Australia’s cane toad ( right) is becoming even more deadly to its predators, resulting in further damage to the ecosystem.
The study looked at the effects of exposing tadpoles to the chemical glyphosate over a period of nine to 61 days.
Author Veronika Bokony, from the Hungarian Academy of Sciences, said the results revealed pesticide exposure could have unexpected effects on other organisms.
“Pesticide pollution might exacerbate the problem of invasive toxic species,” she said.
“For example, in Australia, the survival of native tadpoles is reduced by poisoning from ingestion of toxic cane toad eggs, and predators suffer drastic mortality due to ingesting … cane toads.”
The RSPCA said large doses of cane toad toxins for dogs or cats can be fatal. The animal welfare organisation urges pet owners to seek medical advice if their pet experiences symptoms such as vomiting, difficulty breathing, foaming at the mouth or dilated pupils.
The Hungarian researchers have called for more studies to be conducted around weedkiller chemicals and the chemical defences in bufadienolides.