US researchers planning to do seismic underwater tests off Bermuda have been turned away because of concerns they could harm the hearing of dolphins and whales.

But the scientists from the Lamont-Doherty Earth Observatory at Columbia University in New York say they are planning to submit another submission to carry out the tests next year.

And the organisation's marine safety and environment coordinator Michael Rawson told he was not aware of proof that the use of underwater airguns to do acoustic testing causes harm to marine mammals.

The research ship arrived at Bermuda on November 9 without permission to carry out the tests, which are designed to find out what part of changes to the sea floor around the Bermuda Rise is caused by thermal changes and what is chemical.

Mr. Rawson admits there was a mix-up in the application process resulting in the team not having permission when they arrived on the Island, and he said yesterday he did not blame Government for turning them down.

The story was broken by Bermuda's newly-established environmental website, envirotalk. org.

Environment Permanent Secretary Brian Rowlinson said the application was rejected because environmentalists and the Department of Conservation Services had serious concerns that the technology could damage the hearing of mammals and dolphins.

And he accused the scientists of not highlighting the potential dangers to mammals when they submitted their application for permission to do the tests.

Last Friday, the ship, with 35 crew and scientists on board, turned around and headed back for New York, having wasted at least $100,000 on the trip.

The Lamont-Doherty team submitted its plan to the US State Department, which passed it to the Foreign and Commonwealth Office in London, who then sent it to Government House, and finally the Department of the Environment for approval.

Mr. Rowlinson told last night: "The application got overlooked at this end and did not get prior approval before they arrived.

"When they arrived it was brought to my attention that concerns were raised by the Department of Conservation Services about the negative effect on marine mammals.

"I am told that seismic testing is akin to underwater explosions that can have a damaging effect on marine mammals and as they rely heavily on hearing for communication, this can be extremely detrimental, and it is a science that has drawn criticism here and locally.

"They realise they didn't handle the application process properly. We were asked through the State Department to explore them explaining in more detail to our experts what they are proposing to do.

"My understanding is that local conservationists and the Department of Conservation Services continue to have serious doubts about this, but we will grant them the opportunity to be heard next Monday."

The Lamont-Doherty team will be in Bermuda on Monday to explain the tests and seek permission to carry them out next year.

When asked if he thought they would meet approval, Mr. Rowlinson said: "It is hard to comment without the benefit of their submission, but there is very strong opinion against this science. But we will keep an open mind."

He said the application had been turned down because of fears the testing could be harmful to mammals; there was no prior approval for the tests; and because the initial application did not draw attention to the impact it could have on mammals.

In an application paper prepared by Lamont-Doherty Earth Observatory for for the US National Marine Fisheries Service, the researchers state more than 20,000 mammals ? including sperm whales, beaked whales, bottlenose dolphins, short-beaked common dolphins, and long and short finned pilot whales ? fall within the test area around Bermuda and could potentially hear the seismic tests.

But Mr Rawson told yesterday that possibly only a few dozen might heard the sound waves, and none would be harmed.

The application paper states: "Although it is unlikely that the planned airgun operations could cause PTS (Permanent Threshold Shift ? which damages hearing) in any marine mammals, caution is warranted given the limited knowledge about noise-induced hearing damage in marine mammals, particularly baleen whales.

"The planned monitoring and mitigation measures, including visual course, alteration, ramp-ups, and power downs of the airguns when mammals are seen within the 'safety radii', and will minimise the already-low probability of exposure of marine mammals to sounds strong enough to induce PTS."

The testing involves 20 airguns shooting down into the ocean and ocean bottom hydrophones being towed behind to pick up the returning acoustic signals.

And Mr. Rawson said the ship had a team of mammal spotters on-board and if any dolphins or whales were seen, the tests would be suspended.

"I would say the number of dolphin that might be exposed to low level sound might be about two dozen. That means they would have heard the sound but it wouldn't harm them," he said.

"We've been doing this for 25 years and we've not left a trail of dead mammals. In fact, I've never actually heard of one death that has come directly associated with seismic operations.

"It is a little disappointing but it is perfectly understandable. Each coastal state has its own environmental regulations, however, this event shows that we don't have access to whatever environmental requirements are followed by each coastal state. We did not know to whom we should submit data about clearance.

"In a lot of ways it was probably our fault, but I did try to get this information, but foreign research clearance for Bermuda is through Britain so that the information we provided there sometimes doesn't get back to Bermuda until late in the process, and that's what happened here.

"I in no way consider that this was treated unfairly by the Bermuda government at all. I understand the Bermuda government advises the British government on whether to approve or not and I realise there has been a disconnect in the foreign clearance process in providing information to coastal states."

Mr. Rawson said the nearest the scientists would come to Bermuda was 19 miles, and they would be testing as far north as 200 miles, and as far south as 150 miles.