Extermination efforts continue after invasive ghost snail detection at Port of Brisbane

Australia Broadcast Center

19-06-2025

A leading biosecurity officer says it will be several months before Australia can be declared free of a "speedy", sourdough-loving, invasive snail with the potential to infest hundreds of plant species.
Citrus, cotton, soybean, blueberry and peanut are among the crops being damaged overseas by the snail, which is becoming a costly problem for the horticulture sector in parts of the United States.
The "peanut" or "ghost" snails were discovered by workers at the Port of Brisbane on March 14.
Jim Eldridge, the director of the federal Department of Agriculture, Fisheries and Forestry's (DAFF) technical response team, said his staff were at the site within hours.
He said more than 350 of the snails, scientifically named Bulimulus sporadicus, had been collected and culled from nine sites within the port, preventing the harmful plant pest from taking hold in Australia.
"In excess of 500 plant species might be at risk — obviously they would include fruit and vegetable crops, but they could also include important native species as well," Mr Eldridge said.
"The other risk associated with snails is the fact that they can carry and transmit harmful human and animal bacteria and parasites.
"They could also pose a risk to our native snails by spreading disease or through competition."
Mr Eldridge said his team was "crawling around on hands and knees in the debris, leaf litter and grasses" to capture the "speedy" snails, which moved faster than other shelled gastropods.
The treatment plan also includes using raw sourdough starter – fermented bread dough – to lure them into traps.
Mr Eldridge said it would take several more months before the the infested area could be declared free of the pest because of its ability to aestivate.
That means that in dry, hot times, the snails can seal themselves within their shells and remain dormant for months before becoming active again during wet weather.
"That's why it's important for us to carry out our post-treatment surveillance for an extended period of time — at least 12 months," Mr Eldridge said.
"And that we carry this out across seasons and especially following rain events."
He said salt barriers have been installed to prevent the pest from accessing shipping containers entering and exiting the port.
Investigations into how they arrived are ongoing.
Mr Eldridge said the geographical isolation of the Port of Brisbane on Fisherman Islands was aiding the extermination process.
Originating in the Caribbean, the ghost snail has a conical shell, grows up to 25 millimetres long and is an accomplished climber.
In the southern US the invasive species has spread along rail lines, hitching rides on carriages, people and farm equipment.
The snails' favoured diet is dead and decaying plant matter, but they have damaged crops in the US by sucking plant juices.
Assistant professor Lauren Diepenbrock from the University of Florida's Citrus Research and Education Centre said the snails' biggest impact was clogging irrigation lines, crucial for watering citrus crops.
"Management is a huge challenge," the entomologist said, explaining that there was no known form of economical chemical control.
"We have been screening pesticides, including insecticides, molluscicides, herbicides, and fungicides to find any tools that may currently be available," Dr Diepenbrock said.
On one organic farm geese are being used to help control them.
University of Florida researchers have recorded the snails moving 21.8 metres in 22 days.
"A snail's pace is normally quite slow — these guys can be deceptively quick," Citrus Australia chief executive Nathan Hancock said.
"If they do get up into trees, they do feed on the fruit, which damages it and makes it unsaleable."
In the last financial year the Australian Horticulture Statistics Handbook valued the citrus industry, which produced 883,527 tonnes of fruit for domestic and export markets, at $1.1 billion.
Mr Hancock said that the detection of ghost snails was an example of why biosecurity funding needed to be increased.
"We've seen over time the Department of Agriculture's budgets reducing year on year," Mr Hancock said.
Agriculture, Fisheries and Forestry Minister Julie Collins said biosecurity funding had been increasing.
"The government is contributing more and now importers are also paying their fair share," she said in a statement.
"The Albanese Labor government will continue to work with farmers and important stakeholders so producers are involved in the policy solutions that protect their livelihoods."
In February the federal government scrapped an unpopular proposed biosecurity levy that would have collected $50 million from the agricultural sector.
ABC Rural asked the Department of Agriculture, Fisheries and Forestry (DAFF) how much was being spent on federal biosecurity this financial year compared to last financial year but did not receive a clear answer.
The ABC was directed to a public report released last October that showed $792m had been committed for the 2023-24 financial year.
In that time biosecurity officers supported the clearance of more than 113m imported cargo consignments, 138,000 containers, 19m international travellers, 19,800 vessels and 104,000 international aircraft arriving in Australia.
A DAFF spokesperson said the biosecurity budget was not separately announced in the 2025-26 budget.
"DAFF will release the 2024-25 biosecurity funding and expenditure report later this year," they said.
The Invasive Species Council of Australia said there was "widespread acknowledgement that biosecurity has long been underfunded".
"The main evidence is that we keep getting new invasive species arriving in Australia," senior policy adviser Carol Booth said.
Unlike varroa mites and fall armyworm, which have successfully invaded Australia, ghost snails have been kept out so far.
Mr Eldridge said Bulimulus sporadicus had been intercepted about half a dozen times at Australian ports since 2016.
"All those previous detections were quickly and effectively treated, preventing this snail from establishing," he said.