This article is more than 9 years old

This article is more than 9 years old

Conservation groups in Australia say a decision to allow Shell to carry out exploratory drilling near Australia's newest world heritage site, Ningaloo marine park, could devastate the area if there was a spillage.

"It beggars belief that the government is not requiring a full environmental estimate of this drilling proposal," said Paul Gamblin of the World Wildlife Fund.

Instead, the energy giant must abide by certain conditions, including visual observations for whales. The Australian government said Shell's proposal did not require further assessment.

Ningaloo reef, about 750 miles north of Perth, is best known for its whale sharks, the world's largest fish. The 160m long reef is also home to rare and endangered wildlife including whales, sea turtles and birds. Ningaloo marine park, which includes the reef, was designated a world heritage site last month.

The exploration well will be dug 30 miles from the edge of the park, primarily in search of gas.

In a statement Shell said it was "mindful of significant biodiversity and heritage values of the Ningaloo region and plan to continue our operations accordingly". The proposal said in the unlikely event of a spillage travelling towards the reef "there is sufficient time to collect dispersant and boom...to contain any damage."

Several drilling and floating platforms already operate to the north of the reef but conservationists say this well – to the west – would expose a much bigger section of the reef to danger.

"One of our main concerns is a spill off the side of the reef because of the way the winds and currents work – there's only so far for a spill to go before it ends up hitting the reef," added Gamblin. The area is also prone to cyclones.

Two years ago Australia suffered its worst oil disaster in the Montara oil field off the northern coast of Western Australia. It took three months go bring the spill, which led to 2000 barrels of oil spewing into the ocean each day, under control.

The government says since Montara it has adopted a "more rigorous approach for the assessment of offshore drilling".