The current myrtle rust incursion on the small New Zealand territory of Raoul Island (1050km north of Cape Reinga) is a severe wake-up call about the threat of invasive plant pathogens to our productive and natural plant systems.
“It is a reminder of the constant need for vigilance and preparedness” says Dr David Teulon, Director of Better Border Biosecurity (B3).
The discovery of myrtle rust on Raoul Island is an example of how successful multi-organisational information sharing can be, as the finding was almost wholly attributable to the attendance of DOC advisor, David Havell who, following up on reports of unusual damage to trees from the Raoul Island weed team, recognised myrtle rust following experienced gained from being a member of DOC’s Myrtle Rust awareness team and by attending a myrtle rust workshop organised by MPI, B3 and the Australian Plant Biosecurity Cooperative Research Centre (PBCRC) which was held in December 2016 to raise the profile of this unwanted pathogen.
“Myrtle rust has been recognised as a severe threat to New Zealand for many years. The fact that it has taken seven years for this highly invasive and easily spread pathogen to reach New Zealand (albeit the offshore Kermadec Islands) is a great reflection of the effectiveness of New Zealand’s biosecurity system.
“If this pathogen reached the mainland, some of our best-known native plants, such as the iconic pōhutukawa, rātā, kānuka and mānuka, as well as many lesser-known species, such as swamp maire and ramarama, could be attacked and exotic plants such as Eucalyptus species and feijoa are also at risk.”
A whole range of preparedness activities has been undertaken since the risk of myrtle rust spreading to New Zealand increased dramatically when the disease became established in Australia in 2010. A number of these activities are currently helping to underpin the current response to the Raoul Island incursion. They include:
- A comprehensive analysis of myrtle rust’s environmental and economic impact in 2011 (MPI)
- Climate modelling to determine the survival and spread of myrtle rust in New Zealand (B3/Lincoln University)
- A keynote speaker from Australia at the B3 Conference in 2014
- Development of a molecular method to quickly and accurately identify myrtle rust (MPI/B3)
- A DNA barcoding database linked to a herbarium for accurate host plant identification (Scion)
- Māori/Pacifica summer students publishing on the risks of myrtle rust to taonga species (Plant & Food Research/B3)
- A range of presentations to the New Zealand science community including the New Zealand Plant Protection and Ecological Society conferences.
- Strengthened Plant Import Health Standards as myrtle rust expanded its distribution around Australia and the Pacific (MPI)
- Strengthening of surveillance targeted towards unwanted organisms, such as myrtle rust, in the new forest High Risk Site Surveillance programme (FOA/MPI/Scion/B3)
- Utilising “Sentinel Plants” to help understand the potential impact of myrtle rust on New Zealand natives in Australia (Scion/B3) and linking with urban surveillance programmes for myrtle rust undertaken by Auckland and Wellington botanical gardens.
- A review of the potential impact of myrtle rust on the New Zealand forestry sector in 2016 (Scion)
- A consciousness-raising myrtle rust workshop in 2016 (MPI/B3/PBCRC) attended by David Havell and many of the DOC and MPI response team for the Raoul Island incursion.
“The ability to work on a pathogen that is not present in the country is difficult and relies greatly on close collaborations with overseas colleagues such as within the Australian PBCRC. Despite these limitations, considerable progress has been made,” says David Teulon.
Current and ongoing activity includes:
- Determining of the susceptibility of several iconic native plant species to myrtle rust (Scion/Biological Heritage National Science Challenge/B3).
- Māori solutions to biosecurity threats and incursions to taonga species (Biological Heritage National Science Challenge, Plant & Food Research, BioProtection Research Centre, Te Turi Whakamātaki).
- Detection tool (lateral flow device) being developed for early detection of myrtle in the field (MPI/FERA Science Ltd, UK/Plant & Food Research)
B3 is also intending to use myrtle rust as a model organism to develop biosensors for effective and early detection of pathogens, through a project at Plant & Food Research and Auckland University, and it is seeking funding for additional surveillance and eradication technologies in other areas.
“While New Zealand has one of the best border biosecurity systems in the world, it is continually under threat from new pests, diseases and weeds. All B3 partners (government, industry, science) are working hard to defend our border from these threats,” Dr Teulon says.
Better Border Biosecurity (B3) is a multi-partner, cooperative science collaboration that researches ways to reduce the entry and establishment of new plant pests, diseases and weeds in New Zealand. B3 is aligned to the Biological Heritage National Science Challenge.