How Predator Free plans to wipe out these pests once and for all

Friday, 17 November 2017

Predator Free 2050 has revealed its four-part four-part science research strategy to achieve a scientific breakthrough for dealing with a mammalian predator.

Predator Free 2050 is searching for a science breakthrough capable of eradicating a mammalian predator from the New Zealand mainland.

But to be usable, it'll have to be ethical - and have support from the public. That means you can help choose how the country should get rid of rats, stoats and possums.

The organisation has revealed its four-part science research strategy to achieve the breakthrough - one of its 2025 interim goals.

The strategy has four programmes: environment and society, eradicating the last one per cent, new genetic control tools and computer modelling.

One of Predator Free 2050's goals is to find a way to deal with the 'remaining one per cent' of predator populations.

Distribution of selected exotic pests in New Zealand by millions of hectares at 1 July, 2007.

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A rat caught in a rat trap mounted on a tree. Rats are one of the three predators Predator Free NZ is focusing on eradicating.

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GENE EDITING OPTION

A photo of a possum caught in a trap in the Mt Aspiring National Park taken by Aspiring Hut warden, Donald Lousley.

One of the many eradication options Predator Free 2050 had been considering was gene drive - or gene editing.

A gene drive system promotes the inheritance of a particular genetic variant to increase its frequency in a population.

Threatened native species by taxonomic group in New Zealand at December 2005.

This method would require fewer invasive organisms to be released in order to spread infertility and ultimately eliminate the population.

RISKS INVOLVED

Four stoats killed by a single trap set in the Ruahine ranges.

Scientists working with new genetic technologies have reiterated previously held concerns about the techniques.

Professor Neil Gemmell, the head of the University of Otago's Department of Anatomy, believes there is still 'huge merit' in using genetic technologies for conservation work.

However, he says standard self-propagating versions 'may be uncontrollable' and therefore unsuited to conservation.

In an article published in PLOS Biology, Gemmell and Assistant Professor Kevin Esvelt of MIT, who first described how gene drive could be accomplished by making CRISPR genome editing heritable, examined the possible consequences of the accidental spread of existing self-propagating gene drive systems.

They said Esvelt's original suggestion that self-propagating gene drive systems might be suitable for conservation 'was a mistake'.

'The bottom line is that making a standard, self-propagating CRISPR-based gene-drive system is likely equivalent to creating a new, highly invasive species – both will likely spread to any ecosystem in which they are viable, possibly causing ecological change.'

Introducing such a system 'without the permission of every other country harbouring the target species would be highly irresponsible', the pair said.

'Even assuming that national sovereignty is morally irrelevant, the social and diplomatic consequences of an unconstrained release should give us pause.'

The pair said: 'It would be a profound tragedy if New Zealanders - or anyone else - inadvertently caused an international incident and the consequent loss of public confidence in scientists and governance prevented us from realising other benefits of biotechnology.

The duo appear to have caused quite a stir with their statements, attracting criticism from within the science community.

Dr Andrea Byrom, director of New Zealand's Biological Heritage National Science Challenge said: '… contrary to the implication in the article itself, New Zealand has already taken a cautious and responsible approach to the use of gene editing technologies for mammal pests - the points made by the authors are nothing new…

'Contrary to the hype, gene drive technology for mammals is still highly theoretical, and I must emphasise that no such research is currently being conducted in New Zealand.

'We have literally years of technological development ahead of us before we could proceed with deployment in the field, and future use of gene editing technologies, including gene drive, will be in the hands of the public of New Zealand to decide.'

In a statement responding to Gemmell and Esvelt, Predator Free 2050 said the organisation welcomed their warning of the risks involved with unsafe versions of gene-drive technology.

Comments from its chief executive, Ed Chignall, supported Byrom.

'Beyond exploratory work testing the concept in laboratory mice and running computer simulations, there is no current research to develop gene-drives for Predator Free 2050's targets for eradication (possums, rats and stoats). Nor are there any plans for such research in the near future…

'The focus of the strategy, as it relates to new genetic control tools, will be the facilitation of a national conversation – informing New Zealanders and international observers about the benefits and risks of such technologies.

'Any decision to advance research in this field for application to Predator Free target species will require clear public support and robust scientific debate as to the safety and efficacy of the technology.'

CAUTIOUS APPROACH

Dr Dan Tompkins, Project Manager for the Predator Free 2050 Ltd Science Strategy, said 'What they [Gemmell and Esvelt] are saying really is a good and accurate message.

'What I think has got people upset - those who are upset - is that it's the implication is that everyone else isn't thinking the same way, and everyone is thinking the same way already.'

The focus of the organisation's research approach was informing a national conversation.

The first programme was to explore social and cultural views about predator eradication.

It signalled Predator Free 2050's commitment to transparency and dialogue right from the outset, Tompkins said.

'A science breakthrough without a deep respect for ethics and the social licence to operate is no breakthrough at all.'

Elements of the 'environment and society' programme were underway through a bioethics panel and a recently completed social survey - both initiated by the Biological Heritage National Science Challenge.

The second technical programme aimed to inform people of the benefits and risks of 'new genetic control tools' before committing to any.

Tompkins acknowledged concerns about the approach and that there were many technological hurdles to overcome.

'Predator Free 2050 are not advocating for any specific technology to achieve New Zealand's eradication goals. The organisation's role is to advance our understanding of the range of options available for the task and facilitate a national conversation as to which approaches meet our collective social, ethical and practical standards.'

'Informed by international perspectives, New Zealand stakeholders need to collectively decide which technologies should have a place in the Predator Free 2050 vision, and which should not.'

THE REST OF THE PUZZLE

'A programme on 'eradicating the last one per cent' focuses on upgrading current predator control approaches. While New Zealand is a world leader in mammalian pest control, eradication and keeping areas predator free remains a challenge,' Tompkins said.

Initially, the eradicating the last one per cent programme would focus on possums.

But it would require a shift in thinking, Tompkins said.

'A mate of mine, the way he describes it is that you are going from thinking about 'what's the best way to control populations?' and the 'question now is what's the best way to control individuals?'.

'What is it about those individuals and why do they survive and can we find ways to get around that?'

Handling eradication in urban and rural areas would would require different approaches, too.

The fourth programme, computer modelling, involved the development of shared tools that all communities and agencies contributing to Predator Free 2050 can use to design the right approach for their goals and environment.

Initial social research project findings show that most New Zealanders support the need for pest control: https://t.co/Mxs94dqAlF #PredatorFree2050 @BioHeritage_NZ pic.twitter.com/pnJXyKSVAv

— Dept of Conservation (@docgovtnz) November 15, 2017

SUPPORT FOR THE PREDATOR FREE 2050 APPROACH

Byrom said the New Zealand's Biological Heritage National Science Challenge stood behind the Predator Free research strategy.

'The Challenge has always recognised that the Predator-Free vision is bigger than all of us, so we support a collective effort - including a coordinated and joined-up science and research effort - to achieve this goal.'

The release of the research strategy follows Predator Free 2050 Ltd's recent call for expressions of interest in funding and support for landscape scale predator control projects.

PUBLIC OPINION

A recent Department of Conservation (DOC)-led survey of more than 8000 people found 84 per cent of people agreed pest species were a 'significant conservation problem'.

Only 14 per cent thought enough pest control was being done.

And 85 per cent agreed investment in pest control was beneficial for future generations.

The findings also showed that in relation to potential pest control technologies including gene drive 32 per cent were comfortable, 18 per cent felt it should never be used and the remaining 50 per cent were undecided or wanting strong controls.