The fight against Phytophthora Dieback in Western Australia Phytophthora Dieback is the biggest threat to biodiversity in Western Australia and has now spread throughout the southwest from Eneabba to Esperance. Red shows current dieback infestation of remnant vegetation across the south west of Australia. Phytophthora Dieback is a deadly introduced pathogen of plants. Scientifically known as Phytophthora cinnamomi, it is classified as a water mould belonging to the new ancestral kingdom Chromista. The pathogen is unusual as it has animal, fungal and plant characteristics. Phytophthora Dieback lives in soil and attacks roots of many native plants. It also destroys animal habitats and threatens whole communities. Banksia communities are particularly susceptible. Dieback can turn a flourishing woodland into a sparse sedge-land. There is no effective cure for Phytophthora Dieback but its spread can be controlled. Humans are the main culprits for spreading dieback, especially over large distances. Dieback can slowly move itself through autonomous spread by swimming in the water in the soil and growing through plant material. Some animals may be associated with its localised spread. People can vector dieback by carrying soil and plant material over vast areas. We can minimise Phytophthora Dieback’s spread through improved community awareness planning and building resources to protect threatened areas. Project Dieback is a Natural Resource Management (NRM) initiative getting community, government and industry working together to take on this challenge.