By James Mitchell Crow of Nature magazine

Fossilized dinosaur tracks that dot a remote 80-kilometre stretch of Western Australia's coastline are under threat from a proposed natural gas facility, say paleontologists.

The tracks were made by multiple species of sauropod, theropod and ornithopod dinosaurs as they walked across mud flats around 130 million years ago. The full extent of the tracks was only revealed in 1994, and they are yet to be thoroughly documented and mapped, owing to their isolated location.

But coastline on which the tracks are found could soon be cut in two by a gas facility. The project, part of a plan to commercialize offshore natural gas fields, would involve construction of a port and an onshore liquefied natural gas production plant. A consortium including Shell, BP and Woodside Energy of Perth would run the facility at James Price Point in the northerly Kimberley region of Western Australia.

Some footprints at James Price Point would certainly be lost should the project go ahead. Proponents of the scheme, including the Western Australia state government, argue that these prints are not among the best examples in the area. However, the bigger concern is that a much larger swathe of the tracks could be lost beneath shifting sand, says Steve Salisbury, a paleontologist at the University of Queensland in Brisbane.

Some of the best prints are located not far south of the point, many of them right on the shoreline, says Salisbury. A report commissioned by the state government, published in December last year, acknowledges that channel dredging and the construction of coastal defense structures such as groynes and breakwaters will affect the distribution of sand, and that the impact on the dinosaur tracks is unpredictable.

According to Woodside Energy, the risk is minimal. "A coastal processes sediment transport study and hydrodynamic modeling have indicated that the development is likely to result in only minor and local disturbance," says a spokesman for Woodside.

But that risk is still too big to take, says Salisbury. Some of the footprints are more than 1.5 meters long, which makes these dinosaurs potentially the biggest ever to have existed on Earth, he says. "To think that these prints could be lost some time soon is outrageous."

But the real value of the site lies in the sheer number and diversity of prints, he adds. "There's nowhere to rival it in that respect," says Salisbury. The marks could provide information not only on dinosaur locomotion, but also on behavior, such as whether the dinosaurs moved singly or in groups.

Decision time

On 6 May, one of the last remaining barriers to the project was removed when the aboriginal owners of the land agreed a deal with the state government to allow the development to take place--although the government had already begun the process to compulsorily acquire the land should agreement not have been reached.

The final decision on whether to approve the project rests with Tony Burke, the federal environment minister, who is waiting for an environmental assessment report from the Western Australia government before he settles on a course of action.

"The Kimberley is a magnificent place," says Burke. "The work on the strategic assessment is not yet complete. When it is presented to me I'll be taking all the relevant issues into account under national environmental law."

At the same time, Burke is also considering a proposal to grant National Heritage listing to parts of the Kimberley area--potentially including the coastline in question. The National Heritage List protects places in Australia with outstanding natural, indigenous or historic heritage value. Burke is set to announce his decision by 30 June.

However, that may not have much of an effect on the proposed gas project. Heritage listing protects an area from anything likely to have a significant impact on its heritage value--unless that impact has been approved by the federal environment minister.

The government of Western Australia says that the tracks have been carefully considered. "More surveys will be carried out before construction, and if disturbance of fossils is necessary, traditional owners and the Western Australian Museum will be consulted on appropriate action," says Gail McGowan, deputy director general of the Western Australia Department of State Development.

Under draft proposals for the project, any action at the site that would affect the tracks would have to involve proper scientific documentation of any fossils that were disturbed, McGowan adds.

The state government expects a final decision on the project before the end of the year. Salisbury is urging paleontologists to write to the minister to voice their opposition to the plan.

This article is reproduced with permission from the magazine Nature. The article was first published on May 11, 2011.