Scientists fight to make invasive pest control palatable to the public

Scientists fight to make invasive pest control palatable to the public

Scientists fight to make invasive pest control palatable to the public

Updated 13 June 2017, 14:45 AEST

Scientists are constantly getting more inventive in the war against invasive pests.

Social scientist Edy MacDonald wants researchers to get more emotional about invasive pest control.

She believes one of the biggest hurdles facing scientists in this area is their own inability to explain their research to the public — and more specifically, their failure to acknowledge that when you're talking about killing animals, people get upset.

"They talk about the facts, they talk about the science … the evidence, the 'p values', the correlations," she says.

"And the public don't listen to that."

Dr MacDonald is speaking at the Australasian Vertebrate Pest conference, which has been hearing about potentially game-changing weapons in the battle against invasive pest animals.

There's a herpes virus to kill off the carp clogging up Murray Darling waterways; more advanced bio-control for rabbits; and a promising technology called gene drive, which may be able to cause the reproductive collapse of some feral animal populations.

However, she cautions scientists to learn from past lessons such as the public resistance to GM (genetically modified) technology.

"People make their decisions not based on the scientific facts, but on their value system," she says.

Dr MacDonald says if scientists don't have a conversation with the public around values, "we're going to the end up with a climate change debacle again" — because facts alone don't ensure public support.

While it's impossible to convince everyone to accept all scientific findings, or welcome every breakthrough in biotechnology, Dr MacDonald insists the public must be consulted, and broadly supportive, before disruptive new science is rolled out.

Especially when it involves animal welfare.

Big hopes for gene drive technology

Australian conservation scientist Karl Campbell, whose job involves killing invasive animals on the Galapagos Islands to protect native species, says most scientists in this space "love animals".

"We're not killing animals because we like doing [it] — if we had other tools to use, we would be using them. But we don't at present," Dr Campbell says.

Mark Tizard, a senior scientist in genome engineering at CSIRO is hopeful gene drive technology could prove to be a transformative pest control tool.

But he agrees with Dr MacDonald that it is necessary to obtain a social license to operate — particularly when that tool is "inescapably GM".

"Traditionally, scientists have been in the back room working away, designing their thing, stepping out with their shiny new invention, showing it to the world," Dr Tizard says.

"And the world goes 'that's fantastic', or 'oh my god, what have you done?'"

"It's become very clear for us, as lab scientists, that we can't just go away and make something and then wheel it out.

Gene drive employs CRISPR (clustered regularly interspaced short palindromic repeats) gene-editing techniques and can be used to engineer inheritance.

A manipulated gene, for example, could be placed into a pest species and that gene would then duplicate in future generations — meaning offspring would inherit the engineered genetic trait.

One suggested use for gene drive technology is to engineer male-only offspring, that could result — eventually — in the total collapse of a pest species.

An ideal outcome, you might think. But scientists are wary of the possible adverse consequences of completely removing a species.

Take the mosquito.

"No more mosquitoes, no more malaria," Dr Tizard says, temptingly.

"But then you've got a gap in the ecosystem. Anyone that understands these things knows that gaps don't last long. They'll be filled be something else and the concern is it will be filled by something worse."

Gene drive technology has an array of potential applications, aside from engineering reproductive collapse — but potential is the operative word.

It has not been proven to work outside of the lab, and there is a myriad of regulatory hoops to jump through before, or if, it is ever introduced into the natural environment.

And Dr Tizard is also well-aware of the public's aversion to GM.

"We have to be on the front foot to ensure we maintain public confidence in the safety of what we're doing … and [we need] public input and consultation," he says.

This is precisely what New Zealand is doing.

"We're going to compare and contrast what New Zealanders think of different [pest control] techniques," Dr MacDonald says.

"Either a poison, something that results in sterile offspring, or … something that perhaps might be genetic and might lead to a death or sterility".

How does the public feel about fish with herpes?

New biological agents are also poised to be unleashed on invasive pest populations.

The carp herpes virus, it is claimed, can kill European carp without affecting other fish species.

Carp make up 90 per cent of the fish biomass in parts of the Murray Darling Basin, and female carp produce up to a million eggs a year.

The Federal Government has estimated the virus will kill 95 per cent of carp in the Murray Darling, and Deputy Prime Minister Barnaby Joyce is an enthusiastic proponent.

But what about the "waste biomass" that would be created?

How will the public react if they see dead fish in their waterways? And how will they feel about the release of a herpes virus into their rivers?

"There's a process ahead to work out how this will be deployed," Dr Tizard says.

Meanwhile, Karl Campbell continues to wage war on invasive pests on the Galapagos Islands.

With his "limited toolbox" (mostly poison), Dr Campbell has helped to bring a majestic animal species — the Pinzon giant tortoise — back from brink.

"I worked on Pinzon Island [and] removed invasive rats"," he says.

"The Pinzon giant tortoise hadn't bred on its own home island for 150 years. Within six months, we were seeing hatchling tortoises coming out that weren't getting eaten by rats anymore.

"The only reason tortoises are still there is because they live for 150 years."

A narrow escape — but a reminder, too, of the vast rewards to be reaped from successful pest eradication.