Kauri disease, also known as PTA (Phytophthora Agathis) is killing kauri throughout the Auckland and Northland areas. It has been identified in the Waitakere Ranges, Great Barrier Island and most of northland’s great kauri forests. The pathogen can exist in soil as spores and it can move in water as a zygote. Symptoms of the disease include foliage yellowing, canopy thinning, dead branches, trunk collar lesions that bleed gum and finally tree death.
Effective treatment is still in the research stage.
The good news is that both Coromandel Ranges and Waiheke Island are free of the disease.
To keep the island’s kauri free of this deadly disease there is a need to know how the pathogen gets from one place to another. Already research shows that it can attach to shoes in dirt, or to the feet of animals such as pigs. It can, also, be accidentally transported in the soil attached to potted seedlings or trees.
Forest and Bird have signs at the entrances of their reserves asking people to clean their shoes before entering the reserves. However, there is opportunity to increase public awareness of the disease and decrease its accidental introduction to our beautiful island. Involving the ferry companies more actively in a ‘keep Waiheke free of Kauri disease’ campaign would be wonderful, as the wharves are the main way that people set foot on the island. Our Local Board could play a big part in supporting public education initiatives and negotiating with the ferry companies in partnership with conservation organisations and Council’s bio-security team to reduce the possibility of the disease ever ‘landing’ here.