The consensus among experts is that the predominant vector for spread of the disease is human activity. This can be seen as 71% of the infected trees in the Waitākere Ranges are within 50 metres of public walking tracks. "Phytophthora" zoospores require water to germinate from the oospore, and can migrate by themselves through waterlogged soil. "P. cinnamomi" zoospores remain mobile for up to 10 hours, and can swim at speeds of up to 58 centimetres per hour. However, their direction of travel frequently changes, so they disperse no more than 6 cm by swimming. Consequently, long-distance dispersal of "Phytophthora" depends on other forms of transport. Feral pigs have been blamed for the spread of kauri dieback due to their tendency to gnaw on the roots of kauri trees, and to transport infected soil on their snouts and trotters. Research in 2017 suggests the transport of infected roots via the gut of pigs is a relatively minor vector for the spread of the disease. While only kauri trees develop the characteristic dieback disease following infection, it appears that seven other native New Zealand forest plants can act as hosts for the pathogen without showing symptoms themselves. These include "Dracophyllum", tanekaha ("Phyllocladus trichomanoides"), tall mingimingi ("Leucopogon fasciculatus"), rewarewa ("Knightia excelsa") and "Astelia trinervia". It is thought that the community of symbiotic mycorrhizal fungi living on the roots of healthy kauri trees may help protect them from "Phytophthora" infection. Auckland Regional Council (ARC) began disease surveys and information workshops in October 2006. A Joint Agency was formed in November 2008 comprising the ARC, Northland Regional Council (NRC), the Department of Conservation (DOC) and Ministry of Agriculture and Fisheries Biosecurity New Zealand (MAFBNZ), to develop joint communications and share information. This was replaced in November 2009 by the National Kauri Dieback Management Programme, sponsored and funded by MAFBNZ, DOC, ARC, NRC, Environment Waikato (EW), Environment Bay of Plenty (EBoP), and tangata whenua. This began a five-year national programme of research and science oversight, surveillance, education and outreach. In 2014 this was renewed for a further 10 years.