Australian officials are investigating a coal-carrying ship that ran aground on the Great Barrier Reef to determine what it was doing in restricted waters and what damage it poses to the pristine waters and diverse species in the area.

Oil is seen next to the 230-metre bulk coal carrier Shen Neng I about 70 kilometres east of Great Keppel Island. (Maritime Safety Queensland/Reuters)

Removing the ship that ran aground on the reef could take some time and will be difficult, maritime officials warned Tuesday.

Two tugboats are already stabilizing the Shen Neng 1, the Chinese-registered vessel that rammed into the Douglas Shoal off Australia’s eastern coast on Saturday.

Salvage experts are flying in specialist equipment from around the country to get the vessel off the shoal, according to Patrick Quirk, general manager of Maritime Safety Queensland.

The ship sustained damage to its water ballast and fuel tanks, as well as to its rudder. Authorities fear it might break apart during the salvage operation and wreck more coral or spill more of its heavy fuel oil into the sun-soaked sea.

The ship has already spilled two tonnes of oil into the pristine waters in the area 70 kilometres east of Great Keppel Island, northeast of Gladstone. It is carrying another 948 tonnes.

As of Tuesday morning, helicopter surveillance showed an oil sheen near the ship measuring 600 metres by 300 metres.

Investigation underway

The Australian Transport Safety Bureau planned to interview crew members and collect evidence Tuesday. Bureau investigators have already interviewed witnesses on shore. It expects to release a preliminary investigation report on May 4.

The area is the world's largest coral reef and listed as a World Heritage site because of its environmental value as home to thousands of marine species.

"We've always said the vessel is up in an area it shouldn't be in the first place," Quirk said.

Quirk said the agency was aware that other ships sometimes used a shortcut through the reef, a practice that will also be reviewed by the federal government.

The ship's owner, Shenzhen Energy, a subsidiary of the Cosco Group that is China's largest shipping operator, could be fined up to about $926,000 Cdn for straying from a shipping lane used by 6,000 cargo vessels each year.