Fishers, farmers, and environmentalists fear a “napalm-like” poison could devastate native species including Murray cod, if it is approved for use in New South Wales.
The state government is seeking approval from the Australian Pesticides and Veterinary Medicines Authority (APVMA) to distribute 10,000 litres of bromadiolone in an attempt to end the mouse plague, which is now in its eighth month.
The APVMA says it needs more information about the NSW plan before it can determine if the second-generation anti-coagulant can be used safely.
Narromine farmer Stu Crawford has written to the regulator asking it to consider the impact bromadiolone could have on native fish.
“I wanted to make sure they’d thought about that … to alert them to the fact that, yes, fish are eating mice and there’s the potential for that poison to enter the food chain through that,” he said.
“It has got huge ramifications and it’s not worth the risk.”
Narromine fisherman and agronomist Mick Harris said he had noticed Murray cod eating mice on the Macquarie River.
“We’ve seen a lot of mice either being regurgitated by fish as they’re caught, as they’re brought into the boat, or released — so cod vomiting or regurgitating up dead mice,” he said.
Mr Harris said a friend recently caught and gutted a Murray cod that had five mice in its intestines.
“Without being too gory and too descriptive … five semi-digested mice, they almost looked embalmed, that have been found in that stomach when that fish has been killed and gutted,” he said.
Mr Harris said managing the mouse plague was complex, but he hoped it could be done without detrimental impact to native species.
“I’m on both sides of the fence here, because mice are a massive issue and they’re damaging livelihoods with crop damage and fodder that’s being smashed,” he said.
“So I’m all for taking these little buggers out, but I want to make sure we don’t damage native fish and other native animals too.”
Napalm mice, napalm fish
NSW Agriculture Minister Adam Marshall recently referred to bromadiolone as the “equivalent of napalming mice”.
Mr Marshall was not available for comment, but has said that more than 400 farmers had registered with the government to use bromadiolone should it be approved.
Mel Gray from Healthy Rivers Dubbo said Mr Marshall’s plan was extremely concerning.
“We’ve had Adam Marshall say he is going to napalm the mice,” she said.
“Well, is he prepared to napalm Murray cod? Because that’s what will happen.
“If this poison is put out into the environment you might as well be directly poisoning threatened and vulnerable species like Murray cod, which is a vulnerable species under federal legislation.
“There is no quick fix for this horrible mouse plague – there is no silver bullet.
“We’re going to have to attack it at different levels in different ways.”
Poison could devastate bird and lizard populations
BirdLife Australia also called on the APVMA to deny the state government’s request, claiming bromadiolone could devastate populations of native birds, particularly raptors.
“BirdLife acknowledges that the current plague needs intervention and that the people in these regions need a solution to this economic and social crisis, but it cannot be at the expense of our ecological communities,” spokeswoman Holly Parsons said.
She said a better choice of bait was zinc phosphide, already in use across NSW.
“While this is not an ideal solution, it poses a much smaller risk than a second-generation rodenticide,” Dr Parsons said.
Lobby group NSW Farmers said it never requested bromadiolone and had been calling on the government to provide rebates of up to $25,000 per farmer to purchase zinc phosphide.
“We’re racing to get 6 million hectares of winter crop in the ground, we’re applying 70 or 80 tonnes a day of zinc phosphide and that’s where we need the support,” vice-president Xavier Martin said.
“This will have a billion-dollar-plus hit on the farm gate if the government doesn’t get it right.”
McCormack says APVMA will make right decision
Deputy Prime Minister Michael McCormack backed the APVMA to make the right decision.
“The APVMA will make sure that any baiting, any drug or any chemical that is used, is safe … that’s what the APVMA does,” he said.
“I know the NSW government wouldn’t put anything in place that is going to be affecting communities and pets and livestock going forward — that’s what the APVMA is doing.”
If approved, it would be the first time that bromadiolone was permitted in Australia since 2016.