Oil spill off Australian coast poses major threat to marine life

Nine weeks after a ruptured oil rig sprang a leak, the catastrophic consequences are becoming apparent. Kathy Marks reports

Sea birds are dying and thousands of marine creatures are at risk from a massive oil spill in the Timor Sea, off north-west Australia, warn the first scientists to survey the isolated site.

A ruptured drilling rig has been spewing oil, gas and concentrate into the ocean for the past nine weeks, but until yesterday the environmental impact was unclear because of the remoteness of the spot, 155 miles offshore. Now a World Wide Fund for Nature (WWF) team has travelled there and returned with a report detailing an ecological disaster unfolding far from the eyes of the public.

Gilly Llewellyn, a WWF biologist who led the survey team, said the leak – the equivalent of 2,000 barrels of oil a day, according to an Australian government estimate – was taking place in an area "teeming with marine life", including dolphins, turtles, sea snakes and migratory seabirds.

The spill, reportedly the worst in Australian waters for 40 years, was "a massive contamination event, spread over thousands of square kilometres", Dr Llewellyn told The Independent. She said: "At one point the sun was setting and we were sailing through this slick that we couldn't see the end of. Then we saw a pod of dolphins surface literally in a sea of oil. It just made me feel sick."

So far, only a handful of dead birds have been found, but Dr Llewellyn, the WWF's conservation director, said most creatures passing through the toxic slick were on the move, so the harm they had suffered was still to be determined.

She warned that the oil, combined with the chemicals being used to disperse it, could affect fish stocks and other marine life for generations.

"If you look at the size of the area affected and the duration of the event, you are looking at a long-term impact on thousands, of individuals exposed to oil," she said, adding that the effects on wildlife of the Exxon Valdez spill 20 years ago were still being observed.

"Oil can be a slow and silent killer ... so we can expect this environmental disaster will continue to unfold for years to come. This is going to have a huge footprint on an amazing part of our marine world, but it may take several years for us to detect."

The operators of the Montara oilfield, the Thai-based company PTTEP Australasia, have failed to plug the leaking West Atlas well, despite three attempts. Engineers say they have come within inches of the target, and will try again this weekend. Three hundred people are working on the problem, with 17 boats and nine aircraft deployed so far.

The area is rich in underwater gas and oil reserves, and exploration is expected to accelerate sharply in the coming years. Martin Pritchard, director of an environmental group in the nearby Kimberley region, said yesterday: "It's not a good look for an industry that wants to continue drilling in this environmentally sensitive area."

Among the hundreds of creatures the WWF team recorded were threatened hawksbill and flathead turtles. Sixteen out of 25 oil-affected birds that landed on Ashmore Reef, 90 miles away, were dying. Scientists say this is a high mortality rate, and although the numbers are not great, they might represent only the birds that have survived to travel that far.

The remoteness of the area, a tropical environment of coral and pinnacle reefs, has kept the scandal "out of sight, out of mind", Dr Llewellyn believes. "If the oil were washing up on beaches, there would be national and global outrage," she said. "But there's only a trickle of information coming out, so it's not getting the attention it deserves."

The Australian government has also carried out a survey of the site, where millions of litres of oil have poured into the ocean from the damaged rig since August. Its findings have yet to be released, but the Australian Maritime Safety Authority said this week that the cost of the clean-up had reached more than 5m Australian dollars (£2.83m).

The Environment Minister, Peter Garrett, said he was confident that everything possible was being done to plug the leak. "The fact of the matter is, it's a fiendishly difficult exercise," he told ABC radio. "I'm concerned about it, but we've put a lot of measures in place not only to monitor it, but to make sure that any wildlife that's affected is properly treated."

Satellite images suggest that the slick has already spread across 6,178 square miles. Dr Llewellyn said her team's findings contradicted claims by the Australian Petroleum Production and Exploration Association this week that they had found no evidence of harm to marine life. "This is clearly a false representation of our results and appears to be an attempt to sweep this under the carpet," she said. "It's like standing outside a burning building and saying the furniture looks fine."