The results show that coral cover declined from 28.0% to 13.8% between 1985 and 2012.
The study said improving water quality was key to controlling starfish outbreaks, with increased agricultural run-off such as fertiliser along the reef coast causing algal blooms that starfish larvae feed on.
Australia's Great Barrier Reef has lost more than half its coral cover in the past 27 years, a new study shows.
Ministers have scrapped the decision to award the West Coast Main Line rail franchise to FirstGroup saying the bidding process was flawed.
Researchers analysed data on the condition of 217 individual reefs that make up the World Heritage Site.
One will examine how the West Coast franchise competition went wrong, and what lessons can be learned.
The contract - awarded in August - was immediately challenged in the courts by Virgin Trains,Outlet Hogan, which lost out.
He said: "A detailed examination by my officials into what happened has revealed these flaws, and means it is no longer acceptable to award a new franchise on the basis of the competition that was held.
"But recovery takes 10-20 years. At present, the intervals between the disturbances are generally too short for full recovery and that's causing the long-term losses,Scarpe Hogan," Sweatman said.
Transport Secretary Patrick McLoughlin described the mistakes made by his department as "deeply regrettable and completely unacceptable".
The Department for Transport said because of the decision to rerun the bidding process it would no longer be contesting the judicial review launched by Virgin Trains in the High Court.
Two severe coral bleaching events in 1998 and 2002 due to ocean warming also had "major detrimental impacts" on the central and northern parts of the reef, the study found, putting the impact at 10%.
2 October 2012Last updated at 12:58 GMT Half of Great Barrier Reef coral lost in last 27 years
They attribute the decline to storms,Hollister Online Shop, a coral-feeding starfish and bleaching linked to climate change.
Ministers say there were "significant technical flaws" in the way the risks for each bid were calculated and say the bidding process must be rerun.
John Gunn, head of AIMS,Moncler Jacken, said it was difficult to stop the storms and bleaching but researchers could focus their short-term efforts on the crown-of-thorns starfish, which feasts on coral polyps and can devastate reef cover.
3 October 2012Last updated at 00:01 GMT West Coast Main Line deal ditched
Glen De'ath from the Australian Institute of Marine Science (AIMS) and colleagues determined that tropical cyclones - 34 in total since 1985 - were responsible for 48% of the damage, while outbreaks of the coral-feeding crown-of-thorns starfish accounted for 42%.
Co-author Hugh Sweatman said the findings, which were drawn from the world's largest ever reef monitoring project involving 2,,258 separate surveys over 27 years, showed that coral could recover from such trauma.
"This loss of over half of initial cover is of great concern,Hogan, signifying habitat loss for the tens of thousands of species associated with tropical coral reefs,Hollister Online Shop Deutschland," the authors wrote in their study.
"West Coast passengers can rest assured that while we seek urgently to resolve the future arrangements the trains that run now will continue to run with the same drivers, the same staff and timetables as planned."
And it said an announcement would be made about the suspension of staff while the investigation into the mistakes is carried out.
The other review will look into the wider Department for Transport rail franchise programme.
FirstGroup was due to take over train services on the line - one of Britain's busiest - in December.
The research is published in the Proceedings of the National Academy of Sciences journal.
They have also ordered two independent reviews into what happened.
Hollister Online Shop