There are no viable long-term methods available to stop the cane toads’ relentless march through WA, a state government strategy review finds.

Frontline efforts to prevent the cane toad invasion across the Kimberley have failed and there are no methods available to stop the toxic creatures, a review has found.

The Department of Parks of Wildlife review into the West Australian government’s cane toad strategy said several proposals to fight the pest had been investigated but were found not viable.

The state government has so far spent $7.8 million trying to combat the pesky amphibians over the past five years.

The proposals included the use of parasitic lungworms to slow or reduce toad populations, fencing to exclude them from critical habitat and creating additional checkpoints to minimise satellite populations.

The review, released on Thursday, also revealed the government’s growing concern to protect islands from the toads – which can swim.

Possible mitigation strategies are being investigated for priority islands, including the Adolphus Island in the east Kimberley, such as the use of audio monitoring to detect the arrival of toads.

Environment Minister Albert Jacob said the focus of the next five years would be on managing the impact of cane toads on native wildlife and preventing the establishment of new satellite populations in the Kimberley.

“The recent discovery of a cane toad in East Perth was an important reminder of why a state-wide cane toad strategy is required, even though cane toads are currently confined to the east Kimberley,” Mr Jacob said.

The cane toad is listed by the World Conservation Union as one of the world’s worst 100 invasive alien species.

It was deliberately introduced into Australia in 1935 in an attempt to control beetle populations in Queensland’s sugar cane fields.

But the plan failed because the toads could not reach the beetles at the top of the cane and instead spread across northern Australia, devastating native wildlife.

The toad’s march has sped up over time, with the front now moving at an average rate of 50 kilometres a year.

However, the species is known to “hitchhike” on freight trucks and cars.

In February, the Department deployed a cane toad detector dog to Kununurra to inspect high priority freight for hitchhiker toads.