Image copyright Getty Images Image caption The ill-fated Costa Concordia crashed into the island of Giglio in Italy and capsized with the loss of 32 lives

A new report identifies the world's most dangerous waters for shipping and says accidents pose a particular danger for some of the most ecologically important areas.

The research says the worst accident hotspots are in the South China Sea, the Mediterranean and North Sea.

Losses are more likely in the future as the number of ships is expected to double, the authors warn.

The study has been carried out for WWF International.

The number of ships traversing the world's oceans has increased substantially over the past 15 years from around 85,000 vessels to 105,000.

While the overall number of accidents taken place has fallen, the WWF report states that many that do take place happen in areas of significant environmental interest.

Since 1999, there have been 293 shipping accidents in the South China Sea and East Indies, an area sometimes called the Coral Triangle, where three quarters of the world's coral is found.

"This is the top accident area because of its associated with tramp streamers, older vessels and unregulated flags of convenience," said Dr Simon Walmsley from WWF.

"The probability is the next accident will be in one of these places, and we've already seen... a Chinese fishing boat and a US navy vessel running aground on a world heritage site in the Philippines."

Image caption The sea areas where ships continue to be lost are also waters of environmental significance

As well as the South China Sea, the other major accident hotspots identified include the East Mediterranean, the Black Sea, the North Sea and around the British Isles.

General cargo ships account for more than 40% of vessels lost at sea while fishing boats account for nearly a quarter. More than half of all accidents are caused by foundering where a boat sinks because of rough weather, leaks or by breaking in two.

The big concern for the authors though is that shipping is likely to double in the next 20-30 years and vessels will be going to riskier places. They point to new ports being built to transport coal from Australia that would bring more traffic towards the Great Barrier Reef.

"In some parts of the world we think the risk is too great for vessels," said Dr Walmsley.

"If there is a spill for instance in the Arctic, there is no method at all for cleaning oil under ice, it doesn't exist, the risk there is absolutely huge. The biggest cod stock in the world is in the Barents sea, if ever we had an oil spill there, it could wipe out livelihoods for decades."

The authors call for increased regulation, in particular to curb ships operating under flags of convenience, which they argue are a significant part of the problem. They also say that climate change models predict an increase in storm surges in the future could impact shipping.

This view on the impact of climate is challenged by Captain Rahul Khanna, who has guided oil tankers through the world's oceans for 15 years. He is now a risk consultant with Allianz Global Corporate and Specialty insurance.

Image copyright Getty Images Image caption An oil covered sea bird found on a beach in northern Spain after the tanker Prestige sank in 2002. The overall economic cost was estimated to be billions of euros

"Ships are made to withstand these natural forces," he told BBC News.

"I personally have experience storms and hurricanes and negotiated them on a well founded ship. Generally, I don't think this will increase accidents as such."

What the industry is concerned about is people. Earlier this year, Allianz produced its annual report on shipping losses. Despite the impact of technology and training, the human element is still the biggest risk factor.

"Clearly in the economic challenges of today people are trying to sweat their assets," said Hugo Kidston, editor of the report.

"They are trying to get their crews to work hard, and in areas like the Baltic this can be a very intense operating environment, so the human element is the big challenge."

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