Pandanus trees along the coast of Agnes Water, south of Gladstone, were once admired by Captain Cook and botanist Sir Joseph Banks when they came to shore in 1770.

Key points: More than 80 per cent of pandanus trees around Agnes Water and 1770 have died, while across south-east Queensland the losses are more than 50 per cent

More than 80 per cent of pandanus trees around Agnes Water and 1770 have died, while across south-east Queensland the losses are more than 50 per cent The leafhopper pest is "almost naturalised" in every pandanus from Fraser Island to NSW's Ballina

The leafhopper pest is "almost naturalised" in every pandanus from Fraser Island to NSW's Ballina Queensland Parks and Wildlife says the re-introduction of predator wasps, killed off by drought, may be considered

But now, most of the plants have been killed by a tiny pandanus leafhopper pest, the Jamella australiae.

"Before they rowed their boat ashore, Sir Joseph Banks wrote in his journal that he saw pandanus for the first time since the tropics," said Joel Fostin, a pandanus dieback specialist.

"That very headland that he would have been looking through the telescope at has now lost over 80 per cent of the pandanus."

Mr Fostin estimates more than 10,000 pandanus trees in the Agnes Water region and around the town of 1770 have died.

The decline of predator wasps has made the pandanus trees more susceptible to the leafhopper pest. ( Supplied: Joel Fostin )

Their deaths are now causing beach erosion and contributing to the death of coastal rainforest trees.

"The erosion prevention that their roots provide is second to none, so certainly there is beach erosion where there is pandanus dieback," Mr Fostin said.

He said it is the same situation along much of south-east Queensland's coast and into northern New South Wales.

"It's almost naturalised in every pandanus from the top of Fraser Island to around about Ballina," he said.

"Across south-east Queensland the losses are already well over 50 per cent."

Fighting pandanus dieback

Mr Fostin is calling on the Queensland Government to allocate funding for pest and weed management to help save the remaining pandanus.

Pandanus trees have been under threat from the leafhopper pest for decades. ( Supplied: Joel Fostin )

"National parks currently don't have money to manage the pests that are invading their ecosystems," he said.

"I have written a letter to the Environment Minister pointing out this lack of funding."

A Queensland Parks and Wildlife spokesperson said a native wasp which preys on the leafhopper was introduced in the 1990s, but their numbers have declined because of drought.

"Dieback seems to occur in bursts, and stresses such as drought are making the trees more susceptible to the pests," the spokesperson said.

"Re-introduction of the wasp may be considered if numbers do not increase with improved conditions."

Mr Fostin disagreed with the department's claims that the drought had affected the wasp.

"Regardless of drought, if the hopper is managed then you don't get these severe dieback cases that south-east Queensland is experiencing," he said.

"Utilising this wasp to control this pest is the first and primary way to prevent pandanus dieback.

''A token release of the wasp won't prevent dieback," Mr Fostin said.

"But consistent twice yearly monitoring of the pandanus populations across the entire outbreak area from top to bottom is how this pest needs to be managed."

Pandanus expert Joel Fostin showing what a healthy tree should look like. ( Supplied: Joel Fostin )

Rehabilitation of pandanus populations

Indigenous rangers from the Gidarjil Aboriginal Corporation have been planting pandanus seeds in Deepwater National Park to help increase their numbers.

"Five of us went to meet Joel and he showed us the bad trees first," said Kelvin Rowe, a ranger with the Gidarjil Aboriginal Corporation.

"We planted the seeds in the ground as we went along and hopefully we'll go back every couple of weeks to see how they go.

"They help shade along the beaches, give shade for the turtles, and the shell is good to eat when they're dry."

Mr Rowe echoed Mr Fostin's call for the Government to step in.

While part of the work is the restoration work to re-establish populations, Mr Fostin believes the focus still needs to be on protecting the mature plants.

"The fact is a lot of the females are under a state of decline and their seed reproduction is very low," he said.