SOME of Tasmania's best known national parks are to be isolated as devil havens in an escalation of the battle to save the marsupial from extinction by a facial cancer.
The controversial first release of 14 healthy devils on Maria Island National Park on Wednesday will be followed by projects to cut-off the disease from other entire landscapes.
The Freycinet National Park is to be fenced off, cleared of its few devils and restocked with healthy animals, the director of Save the Tasmanian Devil program, Howel Williams, said.
Further south, the Forestier and Tasman Peninsulas are candidates for similar projects to preserve wild populations of the animal whose numbers are crashing under the impact of a facial tumour disease, he said.
Up to 90 per cent of devils have disappeared from annual spotlight surveys in Tasmania as a result of the cancer, which is spread through biting.
In the latest survey, the program's biologist, Sam Fox, said the disease was more prevalent than ever in the last stronghold of wild healthy devils, in the north-west of the island.
''It's probably only a matter of time until it reaches the north-west coast,'' Ms Fox said. ''All options, whether isolating on islands or peninsulas, are going to be important.''
About 500 devils are now held in captive insurance populations around Australia, but Mr Williams said large landscapes such as the 9000-hectare Maria Island offered the best chance of maintaining the wild behaviour essential to the species' survival.
''Translocation is one of the methods of last resort and it has to be done carefully with good scientific oversight,'' the Federal Minister for Environment, Tony Burke, said.
The Maria Island release came despite opposition from the Tasmanian Conservation Trust and BirdLife Tasmania, concerned about the predators' effect on wildlife.
Mr Williams said the island's cape barren geese, fairy penguins and shearwaters were potentially at risk from an eventual population of up to 120 devils, but they would be monitored and could be removed.