'Titanic' wreck being destroyed by tourists, marine expert warns  Â

The wreck of the Titanic is being slowly destroyed by tour operators, film crews and trophy hunters who have stripped more than 6,000 objects from the ship since it was discovered on the Atlantic seabed in 1985.

The wreck of the Titanic is being slowly destroyed by tour operators, film crews and trophy hunters who have stripped more than 6,000 objects from the ship since it was discovered on the Atlantic seabed in 1985.

Robert Ballard, who found the Titanic, said that a "circus" has developed around the shipwreck over the past 20 years despite it being the last resting place of the people who drowned when it struck an iceberg on its maiden voyage in 1912.

Dr Ballard, a marine archaeologist who has found dozens of important shipwrecks, said the Titanic should be protected against further damage out of respect for its heritage and for those who lost their lives.

Many of the visits to the Titanic have involved landing heavy equipment on its decks which have caved in under the weight. Some structures, such as the crow's nest, have also been destroyed, he said.

Most of the visits have had little to do with scientific research. "A few years ago a couple of people went down and got married on the bow, ... it's like going to a cemetery to get married," Dr Ballard said.

"We're not against visitation, ... we've supported visitation, but we don't want the visits to be destructive," he said.

"Our goal is to write down guidelines for visits. If you go and visit Stonehenge, you don't knock over the stones. That's what we're trying to do with the Titanic."

Next month, Dr Ballard will make his first return visit to the wreck as part of an expedition funded by the National Geographic Channel to study what has happened to the ship over the past 20 years.

"We've heard all sorts of horror stories and being scientists the best way is to go out and look for yourself," he said.

Dr Ballard carried out a detailed survey of the Titanic after its discovery and will use this archived information to make comparisons.

"We will try to figure out how much of the change to the Titanic has been the result of natural change and how much of the change is human-induced," he said. "Whatever has happened to the Titanic will be very obvious. It will not be something that has been brushed away by the sea or other activities."

The Titanic is remarkably well preserved because, lying on the seabed under 12,000 feet of water, there is very little oxygen to degrade the ship's contents. "The Titanic is in a high state of preservation, particularly inside where you can see furniture, drapery and all sorts of things, Dr Ballard said. "As you go deeper inside and eventually enter the engine room it will be full of crew."

Next month's expedition involves a satellite-guided survey ship which will control three remotely operated submersibles which will explore the ship more carefully than anyone has done previously.

The main robot, called Hercules, carries an underwater arm for manipulating objects as well as a variety of excavation tools. Two other robots, called Argus and Little Herc, carry a battery of powerful lights and high-definition video cameras to produce detailed images of the wreck and the surrounding site.

Although the US Congress passed a law protecting the Titanic from salvage operations, the ship remains vulnerable to ships flying under the flag of other nations, Dr Ballard said.

"The people who have done the salvage are civil servants from France and the people who have been going out with film crews and tour boats are civil servants from Russia," he said.

"It's much simpler for nations to try to protect the Titanic since it is nations that have these assets," he added.

Dr Ballard said he wanted the preservation of the Titanic to set an example for many of the other shipwrecks under similar threat.

"We estimate that there are as many as one million ships of antiquity in the high seas," he said. "With the Titanic we have a wonderful opportunity to bring the public's attention to this fact."