Protecting Australia's Great Barrier Reef

Australia has proclaimed a marine park larger than Britain and Ireland combined. Marine officials in Canberra say only the United States and Canada have adequately managed marine parks. But no park there is more than one-tenth the size of Australia's Great Barrier Reef Marine Park.

According to Graeme Kelleher, Canberra-based chairman of the Great Barrier Reef Marine Park Authority, ''It's easy to declare a marine park on paper - but this one will be managed and controlled by trained staff to preserve the environment.''

The park was put together bit by bit. It now covers 345,000 square miles off the Pacific coast of the state of Queensland.

At present, the authority has direct supervision of only 14 percent of the park's area. It expects the whole park to be controlled by 1986.

Australian concern over the reef's future was spawned by several factors: mass tourism, overfishing, spreading oil exploration, and the encroachment of a destructive form of marine life known as the ''crown of thorns.''

Moves to protect the reef began in earnest in 1975 when the Australian Parliament passed the Great Barrier Reef Marine Park Act.

Mr. Kelleher says there is no way the vast park could be properly policed. ''For that reason, we have to retain public support and cooperation, to be seen as preserving something for people rather than interfering with their activities ,'' he says.

The park is divided into four types of zones: general-use zones with few restrictions on human activity; park zones, where visitors must obey rules like those in force in national parks on land; scientific zones, where access will be limited to scientists doing approved research; and small preservation zones, where no one will be allowed in except, very rarely, scientific teams.

The object is to prevent extinction of Great Barrier Reef's natural resources , which include 300 species of hard coral (there are 40 species in the Caribbean) and 1,500 known species of fish, with many more still to be identified. Many types of birds are part of the park's food cycle.

The park was established by the federal government in cooperation with the Queensland state government.

The attractions of the Great Barrier Reef are being promoted widely. Until recently, foreign tourists had to fly to Sydney or Brisbane and connect with domestic flights. But now Townsville and Cairns, to the north, are on international routes, bringing tourists directly from the South Pacific, Asia, and North America.