Tasmanian researchers have discovered wild fish have a natural resistance to a fatal gill disease which wreaks havoc with farmed atlantic salmon.

Amoebic Gill Disease affects salmon farmed in salt water worldwide.

It costs the industry up to 20 per cent of production, the equivalent of $30 million in Tasmania.

Although the disease does not impact human consumption, infected fish must be bathed in salt water to survive.

For the past five years, federally-funded Tasmanian researchers have been looking for ways to combat the disease.

Doctor Mark Adams from the University of Tasmania said scientists have discovered wild fish are resistant.

"The disease seems to be able to initiate in wild fish, but not proliferate," Dr Adams said.

The researchers hope to uncover why wild fish are resistant and if it can be applied to farmed fish.