A: Kauri dieback is caused by a fungus-like pathogen called Phytophthora agathidicida, which was identified in 2008, and was formerly known as Phytophthora taxon Agathis (or PTA). 

A: The microscopic Phytophthora agathidicida spores in the soil seek out and infect kauri roots, and then damage the tissues that carry nutrients within the tree. Infected trees will eventually show a range of symptoms, including yellowing foliage, leaf loss, dead branches, and often (but not always) lesions that bleed resin at the base of the trunk. 

A: Kauri dieback has been detected (through testing) in a number of places, on public and private land, throughout the upper North Island (which is where kauri naturally occur), including in the Waitākere Ranges, on private land throughout Auckland and Northland, in the forest plantations of Omahuta, Glenbervie and Russell in Northland, on public land at Okura, Albany and Pakiri, in the Trounson Kauri and the Waipoua Forest parks in Northland, and on Great Barrier Island. It’s also been detected on the Coromandel Peninsula, at Hukarahi and on private land near Whangapoua. However you can’t ever assume an area is free of kauri dieback – see below. 

A: It’s a multi-agency government and community response to managing the spread of kauri dieback disease, established in 2009. It is a collaborative partnership between MPI, Department of Conservation (DOC), Northland Regional Council, Auckland Council, Waikato Regional Council, Bay of Plenty Regional Council, and tangata whenua. The programme is governed by a governance group which has representation from all partners.

A: At the start of the programme the Tangata Whenua Roopu (TWR) was established to engage with all Maori who have an interest in kauri dieback disease. TWR elect two representatives for the programme governance group. In addition, Te Roroa in their role as kaitiaki over Waipoua forest (home of Tāne Mahuta and other iconic kauri) have one representative on the programme governance group.

The programme engages with Māori through TWR, DOC and councils, as well as with Te Kawerau ā Maki who have special relationships with a number of areas in the wider Auckland region.

A: It kills most - if not all - kauri that it infects (regardless of age). The delay between a tree becoming infected and that tree showing any signs of the infection varies enormously between trees – it is common to see a tree that has been killed by kauri dieback next to a tree that appears healthy.  

A: Evidence suggests the disease may have been present in New Zealand since at least the early 1950s. Only in 2008, however, were scientists able to identify the pathogen and its role in killing kauri.

A: Estimates vary; definitely hundreds, probably thousands. It is important to note however that all the evidence indicates that the majority of kauri are not infected by kauri dieback. 

A: Yes, but only if everyone who goes near kauri cleans their gear before and after, and stays off kauri roots – by doing the right thing, people do have the ability to save kauri. And there are plenty of precedents for where the public have helped overcome biosecurity threats. For example, many people thought it would be impossible to keep didymo out of the North Island’s lakes and rivers, but so far it’s been kept to the South Island for more than 10 years. And the fruit fly outbreak in Grey Lynn, Auckland in early 2015 was successfully controlled because people did not move fruit from that suburb. 

A: It is highly unlikely that a cure will be found. Phosphite is being researched as a means to slow the spread of the infection within individual kauri, but it does not cure the disease and has only a limited application - if any - in natural forest (trees have to be repeatedly injected with the chemical, at multiple sites on the trunk). The only way to save kauri is to clean gear before and after going near kauri, and to stay off kauri roots. 

A: There is no evidence that any individual kauri are resistant to kauri dieback, although some kauri succumb much faster to kauri dieback than others. 

A: Field observations suggest it does not, but research is being carried out to explore this further.   

A: This is subject to ongoing research, which so far suggests the pathogen came from overseas.

A: It could have arrived on anything that had as little as just a pinhead of contaminated soil on it; e.g. tramping gear, army surplus machinery used in the Pacific during the Second World War, or plant specimens … it’s likely that we will never know for sure.     

A: Any movement of contaminated soil can spread the disease, regardless of whether that soil came from around kauri trees or not. Human activity is the leading cause of infected soil movement (on footwear and equipment). But the pathogen can also be moved by animals such as pigs, by water moving through the soil, and possibly by river and stream water.  Just a single pinhead of soil is all that is needed to spread the disease.

A: No, it is only spread by soil movement, carried mostly by people with contaminated soil on their footwear and equipment. 

A: The pathogen is spread through the soil by water. It is also possible that it is spread by streams and rivers, especially under flood conditions. It’s theoretically possible that birds may spread the disease, but the greater the amount of soil moved, the greater the risk – which puts people - and the things they do - at the top of the list. 

A: Work undertaken by the Programme has not identified any reason to link the use of 1080 to kauri dieback, with the disease detected in areas where 1080 has not been used.

Investigations undertaken by the Kauri Dieback Programme to date have found the water mould Phytophthora agathidicida to be the primary cause of kauri dieback disease, with human activity (through transfer of soil on people’s footwear and equipment) the most common cause of it spreading. For example, the majority (70%) of infected trees in the Waitakere Ranges are within 50m of a walking track, which clearly indicates that humans are the main vectors for spreading this disease.

A: Good hygiene is critical to stopping the spread of the disease. Therefore people must clean footwear and equipment to remove all visible soil when entering or exiting a kauri forest and stay on open tracks.

A: A Controlled Area is an area that has a Controlled Area Notice (CAN) in place under the Biosecurity Act 1993. There are conditions on the CAN that mean if you enter a Controlled Area you are legally required to follow all instructions to protect kauri. The simplest way to remember what to do is: use all cleaning stations you encounter, and follow all instructions at the site. There are currently CANs in place on open tracks in the Waitākere Ranges and parts of the Hunua Ranges.

A: Make sure your footwear and equipment is spotlessly clean before you arrive in the area, and that it has been disinfected with your own supply of Sterigene – if available. Before you leave an area with kauri, put your shoes (as well as dirty clothing and any other equipment that has come into contact with soil) in a plastic bag and take them home with you for cleaning and disinfecting with Sterigene (if available). If you have to go off-track, don’t go near kauri – a kauri’s roots can extend three times the distance from the trunk to the edge of the tree’s canopy; standing on these roots damages them and makes them vulnerable to infection.

A: Early in 2018, the programme announced three new measures to strengthen the fight against kauri dieback disease. These are:

• a Controlled Area Notice (CAN)
• a National Pest Management Plan
• a Strategic Science Advisory Group.

The CAN is an interim measure issued by MPI under the Biosecurity Act 1993. Visitors to Controlled Areas are legally required to follow the conditions of the CAN. It cannot ban people from entering the area, but does control the movement of goods and equipment into and out of the area and cleaning mandatory. 

A National Pest Management Plan is used for tackling major biosecurity threats and is the strongest form of regulation MPI can put in place for an established pest. It will provide consistency for managing kauri dieback disease nationally, with a more enduring programme governance and funding arrangement.

The Kauri Dieback Strategic Science Advisory Group provides independent advice on the strategy and coordination of kauri dieback disease research. It is made up of MPI and DOC Departmental Science Advisers, tangata whenua, senior New Zealand researchers with expertise in relevant fields and an international Phytophthora agathidicida expert.

A: The kauri dieback programme has managed an aerial surveillance operation over the past three years to identify trees showing signs of the disease. This is in conjunction with ground surveillance carried out by councils in kauri regions. The aerial surveillance has identified around 450 sites that will be prioritised by MPI, DOC and regional councils for further investigation.

A: The Ministry for Primary Industries (MPI) has assessed whether the declaration of a biosecurity emergency is an appropriate response to manage kauri dieback and the specific statutory criteria were not met.

Section 144 (declaration of biosecurity emergency) of the Biosecurity Act 1993 sets out the grounds on which a biosecurity emergency may be declared. Emergency powers are not considered to be the appropriate mechanism for management of kauri dieback since the prevention of soil movement that might spread the pathogen can be controlled by a national pest management plan which is currently under development.

There are other appropriate powers available to manage the disease. For example, the pathogen is designated an Unwanted Organism under the Biosecurity Act and the Chief Technical Officer of Biosecurity New Zealand can impose a Controlled Area Notice (CAN) to make hygiene practices a legal requirement for anyone entering or leaving a forest. Regional councils have the ability to list the pathogen in their regional pest management plans, and the Department of Conservation (DOC) has access to powers under the Reserves Act 1977 and the Conservation Act 1987 to manage activities on public conservation land or close access to forest areas.

A: You don’t know your local kauri are free of the disease. Kauri dieback can ‘hibernate’ in the ground for several years. And kauri can harbour the disease for a long time before they show any signs of infection. Therefore you can never assume an area is free of kauri dieback. 

A: Sterigene is highly effective at killing the pathogen that causes kauri dieback in three of its four life stages, although it is not entirely effective at killing the spores in the fourth ‘hibernation’ stage. However in terms of its overall effectiveness, biodegradability and nontoxicity, Sterigene is considered the best product available. 

A: At home, use clean water and a dog-friendly soap or shampoo to thoroughly wash all soil off your dog’s paws and coat. Sterigene should not be used on the paws or any part of your dogs coat.

A: Please only hunt in areas where the disease has not been detected, and clean and disinfect (if Sterigene is available) your gear between forests/catchments. Ensure you arrive at the forest with clean and disinfected footwear and gear. Use tracks as much as possible, and try to avoid going within three times the distance between a kauri’s trunk and the edge of its canopy. When leaving a forest, clean all visible traces of soil from your footwear and gear and disinfect, or (plastic) bag it for thorough cleaning and disinfecting at home. To avoid spreading contaminated soil inside your vehicle, keep clean ‘new’ footwear for the drive home.

A: The muddier a track is, the higher the risk that kauri dieback will be introduced to or spread from a particular area. On popular tracks, it’s a good use of public money to build boardwalks, or to re-route tracks. However sometimes less popular tracks are closed because the cost of the improvements needed to reduce the chances of kauri dieback being spread cannot be justified by the number of users. Tracks are also regularly closed for upgrades aimed at reducing the chances of visitors spreading kauri dieback.

A: The research into the role animals have in spreading kauri dieback is continuing, but it is considered highly likely that pigs in particular do spread kauri dieback. Therefore pig culls have taken place in kauri forests where the disease is widespread. However blanket culls are not being considered at this time.   

A: Kauri dieback research is published under the Science and Research section of the kauri dieback website. New reports will be added as they become available.