One of Australia’s worst pests is on the march to the Pilbara. But we have a ‘unique’ chance to stop them

3 months ago 18

One of the nation’s worst pests are on track to reach Western Australia’s Pilbara region within the next two decades, threatening to cause widespread losses of native species and significant economic and cultural harm.

A new study, published in the journal Scientific Reports, predicts that, without containment efforts, cane toads would continue their march south and infest up to 75 per cent of the Pilbara over the next 30 years.

These cane toads were found in Derby – around 220 kilometres north of Broome.

That would place 25 native species at risk of serious population decline – and eight that are endemic to the Pilbara are at the highest risk.

Native mammals and reptiles are likely to be added to the threatened species list, while species like the already vulnerable ghost bat would be pushed to a higher threat category.

Report lead author Dr Judy Dunlop, from Curtin University’s School of Molecular and Life Sciences, said “Australia’s worst pest” was notoriously difficult to control but had one weakness – it needed water to survive.

Northern WA is unique compared to the rest of the country, Dunlop said, as it lacked natural sources of water, providing a fighting chance to stop the cane toad from spreading.

“Toads are approaching a naturally dry part of the country south of Broome where the Great Sandy Desert meets the ocean. Here, the only water accessible to them is cattle watering points,” she said.

“Toads will access and use them as stepping stones to make their way through the desert zone.”

The key, Dunlop said, was to upgrade 150 pastoral dams between Broome and Port Hedland to concrete tanks and troughs, to stop the toads from accessing them.

The idea is backed by farmers and landowners in the area, and has industry support from BHP and Rio Tinto and the not-for-profit Skip Foundation, as well approval from the state government.

Upgrades to the dams are planned to start next year.

Dunlop said if the cane toad reached the Pilbara – a region with permanent water sources which made it an ideal habitat for the invasive species – it would be “game over”.

“Many people don’t realise how far they have actually spread across WA,” she said.

“They have devastated native wildlife across the Kimberley and are spreading at about 40 to 50 kilometres per year – they will hit Broome in the next two to three wet seasons.

“The chance to stop them through dehydration is a unique one across Australia and must be taken advantage of.”

Report co-author Professor Ben Phillips, also from Curtin’s School of Molecular and Life Sciences, said the “toad containment zone” would be around 150 kilometres long.

Species at stake if the cane toad spreads.

“We may be able to prevent the invasion and push the species back to the top of the barrier – much like how firebreaks are used to halt the spread of bushfires by removing fuel and creating controlled boundaries,” Phillips said.

“There is no doubt that the arrival of toads will cause catastrophic declines in culturally important species, which will be felt by the Traditional Custodians of the Pilbara.

“The animals most at risk – such as the goanna and blue tongue skink – are culturally important to traditional owners for food, storytelling and bush tucker practices.”

Phillips said the findings may also have implications for WA’s mining sector, which may face increased costs and new conservation requirements due to the changing status of local fauna if the toads invaded.

“Our study shows that implementing a model to control the invasion of cane toads could deliver significant environmental, cultural and economic benefits for WA’s Pilbara region and beyond,” he said.