Steps to set up healthy koala colony at Yanchep

Efforts are being made to re-establish a healthy breeding colony of koalas at Yanchep National Park.

Releasing four new koalas into the park's enclosure today, Environment Minister Bob Pearce said the existing colony was infected with chlamydia, a disease common in koalas but which often caused infertility.

"Unfortunately, our existing population of five koalas has not bred successfully for nearly ten years and we have had to seek new breeding stock from South Australia," Mr Pearce said.

"Last night, four young females arrived in Perth, provided free of charge by the South Australian National Parks and Wildlife Service from the disease-free koala colony on Kangaroo Island.

"This initiative is part of the State Government's park improvement program to upgrade facilities and services in the State's national parks," he said.

"We are grateful to the South Australian authorities for their co-operation, and our thanks must also go to Ansett Australia, which generously sponsored the transport of the koalas from Adelaide to Perth."

Mr Pearce said efforts would be made to bring more healthy koalas of both sexes to Western Australia, so that a healthy breeding colony was established at Yanchep.

"In the meantime it is important that the new arrivals are kept separate from the existing koala colony to prevent any cross infection. As a result, the original five koalas have been moved to a new enclosure in another section of the park."

The koala colony is the park's major tourist attraction.

The park draws over 400,000 visitors every year - more than one third coming from interstate and overseas.