Canberra, Dec 16 (IANS): Australian federal and state governments have released a new national strategy to stop the spread of feral deer across the country.

Since 1980, Australia's population of feral deer has increased from an estimated 50,000 to up to 2 million, reports Xinhua news agency.

Deer were introduced into Australia from Europe in the 19th century as game animals. Today, they occupy many areas throughout Australia and cause a variety of environmental problems.

In the same time frame, the range they inhabit on the country's east coast has doubled, meaning they can no longer be managed by recreational hunting.

In response to their spread, federal and state governments have released the National Feral Deer Action Plan, which proposes a containment zone to stop their spread westward.

Feral deer pose a major threat to Australia's native species because they overgraze, cause erosion, trample vegetation, and degrade water quality.

Andrew Cox, chief executive of the Invasive Species Council and a member of the working group that developed the action plan, said without urgent intervention there would be deer across Australia.

"The deer plague has already taken over most natural areas on the east coast," he told the Guardian Australia.

"Scientists now predict that without action feral deer will inhabit every habitat in every part of Australia."

Under the action plan, deer populations that are too big to be eradicated will be managed through aerial culling programs.

A national containment zone would be established along the east coast as well as in South Australia and the island state of Tasmania.

Deer that enter the containment buffer zone will be culled and smaller populations will be eradicated.

Ted Rowley, chair of the working group, said that in order for the national plan to be effective land managers across the country had to work together.