Researchers believe it could be years before we know the origin of an avian cholera outbreak that's killing off eider ducks in Nunavut.

Avian cholera is a deadly disease for birds, but doesn't affect humans.

In 2006, thousands of dead eider ducks were found on Southampton Island. Since then it has been found in Nunavik and south Baffin Island and has also affected other bird species.

But the origins of avian cholera are still unknown.

"We’re interested to know if the disease persists in the environment, the soil and the water of these nesting colonies through the winter or whether [it is] being brought to the nesting islands by the birds themselves each year," said Grant Gilchrist, a scientist with Environment Canada.

Research will take place this summer at eider duck colonies in South Baffin and in northern Quebec.

Gilchirst says the deadly disease is not the only threat to the eiders.

Polar bears are also feasting on eider eggs laid on islands off the coast of South Baffin and Nunavik.

"Bears are extremely smart and adaptable and once they arrive in these islands and eat the eider eggs, they learn to swim to all the coastal islands," he said.

"This last summer for example, over 58 per cent of the islands we visited had been depredated by polar bears and we observed 22 different bears on these offshore islands."

Gilchrist says receding sea ice is likely causing the bears to turn to eggs for food.