The Ministry of Primary Industries has revealed it will stop trying to contain a serious plant disease from spreading further in New Zealand, with myrtle rust now being found in nine regions including the South Island for the first time.
MPI myrtle rust incident controller Catherine Duthie said it is a sad but inevitable day.
"This is a significant development. It's one we've been expecting for a long time now as the number of infections have increased across the country and this signals a change in the overall direction," she said.
The fungal disease, which is windborne, is now widespread in New Zealand’s most vulnerable areas including Northland, Auckland, Waikato, Bay of Plenty, Taupo, Taranaki, Manawatu, Wellington and Tasman at the top of the South Island.
"This is really upsetting. I look out my office window and I see the pohutakawa on Tinakori Hill and they were in bloom all over the summer and it's devastating to think that we might lose those trees," Ms Duthie said.
"I love these plants and they're really important to all of New Zealand."
Ms Duthie said it really hit her how significant the disease is for New Zealand’s environment yesterday in Kawhia, where a special pohutukawa tree stands.
"This tree is thought to be around 1200 years old. It was the tree that the canoes were tied to when they first arrived in this country and so trees like that are at risk," she said.
Hundreds of confirmed infected sites and more likely
Trees from the myrtle species are at risk, including the iconic pohutukawa as well as the manuka, rata, kanuka, ramarama and swamp maire.
Myrtle rust was first found in mainland New Zealand in May last year, with spores arriving from Australia.
The latest discoveries are at five properties at Omori, on Lake Taupo’s south-western edge, and at a home in Collingwood and commercial property in Pohara in the Tasman District.
It brings the total number of confirmed infected sites to 547, but MPI says there's likely to be many more infections than that as the disease can lie dormant in a tree for several years before the yellow, powdery coating is visible on its leaves.
Forest and Bird has shared its disappointment on Twitter over MPI's decision to stop containment of the disease, claiming it has "thrown in the towel" and "given up so quickly on managing the human component of its spread".
“We need to understand all we can about this in the hopes that it in future years there will be a treatment
Ms Duthie said it's done all it possibly could to combat the disease, with the operation most likely larger than in any other country where myrtle rust is found.
Ms Duthie said the disease impacts the country's socio-cultural values more than having an economic impact, and will be significant to most New Zealanders.
MPI has been holding hui with the Maori Biosecurity Network around the North Island to boost awareness of the disease and provide surveillance training to people at marae.
Ms Duthie said the worst-case scenario would be what has happened in Australia where there have been localised extinctions of certain plants.
The impact will be most severe in warm, humid locations around New Zealand.
Wellington City Council and the capital's urban eco-sanctuary Zealandia have upped surveillance of myrtle species, with ramarama, rata and pohutakawa widespread in Wellington's natural landscape and council-managed gardens.
Otari curator Finn Michalak is involved in the country's largest ever targeted seed collection to preserve myrtle species.
He has overseen an attempt to collect genetically-diverse seeds from one of New Zealand's rarest trees, the Bartlett's rata.
There's only 13 plants left in the wild and the species has low resistance to myrtle rust due to little genetic diversity in its small population.
"We don't know which species are going to get wiped out, which ones are going to show to have some resistance in them. So for the time being we will be doing very little in controlling myrtle rust," Mr Michalak said.
"We don't want to be using toxic fungicides which really haven't shown to be that successful against fighting myrtle rust."
The advice to the public remains to look out for the disease on myrtle species and contact MPI about suspected sightings.
People should not touch the fungus or attempt to spray it with fungicides.
Infected plant nurseries have been shut down for some time while MPI attempted to slow the spread of the disease, with compensation offered to those that meet strict criteria including a verifiable economic loss, incident controller Catherine Duthie said.
MPI's change to long-term management also brings with it the decision to stop removing trees in areas where the disease is prevalent.
"Our hope is pinned on the science programme, the long-term management programme… that engagement with communities," Ms Duthie said.
"We need to understand all we can about this in the hopes that it in future years there will be a treatment.
"We have fought until we can't fight any longer," she said.
Myrtle rust by numbers
Properties:
Taranaki - 233
Bay of Plenty - 123
Auckland - 82
Waikato - 61
Wellington - 34
Taupo - 5
Northland - 4
Manawatu - 3
Tasman - 2
MPI work hours - 104,000
Myrtle plant inspections - 95,276
Laboratory tests - 330
Destroyed infected plants - 5000
Suspected sightings from the public - 3300
SHARE ME