The university's school of zoology senior research fellow, Dr Jones, said better management systems to guard the devils against the spread of the cancerous tumour needs to be put in place so that their number does not continue to decline and foxes take a foothold in Tasmania.

If devil numbers are retained there would be more of an equilibrium with foxes, which she believes do exist in the state, and less likelihood that native Tasmanian animals will become extinct.

"We're sitting on the edge of an ecological catastrophe," Dr Jones said.

"With the devil numbers going down, with the foxes present and we know that feral cats are established here, we could be witness to the extinction of Tasmanian wildlife, much of which disappeared from the mainland 100 years ago."

Dr Jones said medium-sized animals like the Tasmanian pademelon, bettong, eastern barred bandicoot, eastern quoll, potoroo and native hen could disappear if more is not done to ensure foxes and feral cats are eradicated.

She said 10 years ago when they were conducting research on the Freycinet Peninsula they would have caught 150 devils, today they would be lucky to find 10; with 50 per cent of those with the devil facial tumour disease.

Dr Jones said the East Coast had seen about a 95 per cent decline in devil numbers, while the North-West has also seen a decline.

She called on people not to be sceptics on the issue of whether foxes existed in the state but to volunteer in devil research work, support the Save the Tasmanian Devil program and also lobby for cat control legislation.

Dr Jones is part of a team of five that is one of three finalists in the 2011 Sherman Eureka Prize for Environmental Research.

The prestigious science prize will be announced tomorrow night in Sydney.