BERMUDA'S sea turtles have a battle on their hands just to remain alive, thanks to the habits of us humans. Many perish in collisions with speeding boats, get entangled with fishing gear or block their digestive tracts after eating plastic they find among ocean debris.

But while the threats to the survival of the green, hawksbill, loggerhead and leatherback turtles which frequent the island's waters off the North Shore are considerable, the people behind The Bermuda Turtle Project are doing their best to help protect these remarkable creatures by making us all more aware.

The aim of the project, which is sponsored by the Bermuda Aquarium, Museum and Zoo (BAMZ) and the Caribbean Conservation Corporation (CCC), is "to promote the conservation of marine turtles through research and education".

The tagging study was started in 1968 by Dr. H.C. Frick II, a trustee of the CCC, but Bermuda's history of protecting its marine turtles goes back far beyond that.

For example, in 1620 the Government passed an 'Act Agaynst the Killing of Ouer Young Tortoyses' in response to mariners' habit of hunting the creatures in bulk to stock up with turtle meat and oil when they stopped off at the island during the early 17th century.

Despite such conservation efforts, in the space of a further 300 years, nesting by green turtles on the island had all but ceased.

Now only immature turtles inhabit Bermuda's largely unpolluted waters, but here there is one of the healthiest populations of green turtles anywhere in the Atlantic basin.

BERMUDIANA the sea turtle made an epic journey of more than 1,000 miles from the waters off Bermuda, all the way to the Dominican Republic.

Her adventures continued there as she survived in tumultuous seas in the Caribbean, whipped up by Hurricance Georges, with no apparent ill effects.

Shortly afterwards she swam to waters off the coast of Cuba and her fate from that point is uncertain, but it is thought she was captured by turtle hunters and killed for her meat.

The Bermuda Turtle Project (BTP) has all this information about Bermudiana, because in 1998 she was fitted up with a tiny transmitter, just two weeks before she decided to move south (see map above).

The transmitter emitted a signal every time the turtle surfaced to breathe, and recorded location, dive frequency and duration, and temperature. Using satellite technology, the BTP staff were able to track her progress and monitor some of her habits.

The exercise gave a remarkable insight into the life of these mysterious creatures. It is the kind of work which, according to a top British marine scientist visiting the island this week, has made Bermuda's project a world leader.

"The Bermuda group is undoubtedly one of the best sea turtle projects running anywhere in the world," said Dr. Brendan Godley, a co-ordinator of the global Marine Turtle Research Group, who spoke at this week's International Conservation Conference at the Elbow Beach Hotel.

"It is a role model we are trying to promote in other British Overseas Territories. Most of the sea turtle research we see being done is on the nesting beaches, because it's easy.

"If you really want results in terms of research you have to get into the water - and that's what's the people here are doing.

"I came over here in August and I was blown away by the people working on an excellent 30-year programme. I can't speak highly enough about it. It really is something for Bermuda to be proud of."

The project's findings have shown that Bermuda serves as a year-round habitat for juvenile green and hawksbill turtles, providing a developmental feeding ground for animals which go on to breed further south.

Data collected by catching and tagging turtles every year show that green turtles arrive in Bermuda when they are about ten inches long and leave by the time they have grown to 30 inches - which means they often stick around for 20 years or more.

Jennifer Gray, of the Bermuda Aquarium, has been co-ordinating the Bermuda Turtle Group for the past 11 years, but her involvement in some capacity goes back to 1977. She said the tagging programme had revealed a disturbing trend which showed why the future of the marine turtles was under threat.

"Most of our data comes from tag returns and it shows that many of our turtles end up at Mosquito Quay, Nicaragua, which is one of the largest feeding grounds in the Atlantic for green turtles," said Ms Gray.

"Unfortunately, many are not living to breed and complete the life cycle, because they are being caught by fishermen. Our tags come with a reward for returning and we have a representative down there who collects them for us.

"We have tagged more than 2,000 turtles and we don't want to see too many of those tags returned because it means they are not alive to breed.

"We are seeing a high number of turtles taken in the Dominican Republic and Cuba. That appears to be a route used by them before they get to Nicaragua."

Ms Gray said the Bermuda Turtle Group wanted to get the conservation message across to countries further south. It is possible that Bermuda could lose the green turtle one day, if they are not protected in their adult ranges and nesting grounds.

Bermuda's turtle population started life in various locations around the world. Ms Gray said their DNA had matched similar samples taken as far afield as Ascension Island, as well as the Caribbean region and the southern United States.

They come here to feed and grow in crystal clear waters, among healthy coral reefs and lush seagrass beds, in the total absence of adult turtles. But how do they actually know to come here and how do they find their way, in the months after their birth, to this tiny mid-Atlantic island?

"It is one of the great mysteries of nature, how migratory animals know where to go," said Ms Gray. "With turtles, it seems they have some sort of internal compass.

"We do know they are capable of reading magnetic fields off the ocean floor and using them to navigate.

"But how they find their way back to the nesting beaches where they were born to breed, that remains to be seen."

Capture and recapture of young green turtles off Bermuda for the project has shown they like to feed in specific areas. One turtle was captured on seven different occasions, each time on the same grass flat.

The longest that one individual turtle is known to have lived in Bermuda is 12 years, though it is thought probable that many reside here for more than 20 years. Turtles can take 30 years to mature fully and be ready to breed.

When they leave the island, they embark on the long journey back to the adult resident habitat where they breed and start off the life cycle of the next generation.

Turtles tagged in Bermuda have been discovered in Venezuela, Nicaragua, Panama, Cuba, the Dominican Republic, St. Lucia and Grenada.

The first time a satellite transmitter was attached to a Bermuda turtle was back in 1996. It gave data for 15 months during which time the turtle did not leave Bermuda's waters.

It takes a green turtle between 30 and 50 years to grow their shells up to one metre (3.3 feet) in length. But to reach that age, they must survive the perils of the ocean, some the result of human activity, some not.

Eggs, laid on beaches, and hatchlings, risk being attacked by ants, crabs, birds, dogs and cats on land, while the new-born turtles, about the size of a dollar coin, and once they reached the sea, would be at risk from marine carnivores such as snappers, groupers, barracudas and sharks.

Another natural threat during the vulnerability of their start to life would come from tropical storms and hurricanes, capable of eroding nest sites.

Bermuda is no longer a nesting ground for green turtles and, at juvenile size, the only enemies they have in our waters are sharks and man.

"By comparison to other regions, Bermuda is a safe place for turtles to be," said Ms Gray. "This is one of few places in the world where turtles enjoy complete protection.

"We have a pristine environment because we care for our island and our pollutants are carried away and dispersed by the ocean."

But there were still threats to turtles stemming mainly from the carelessness of humans, Ms Gray added.

Avoiding boats moving at high speed is difficult for turtles and increasing numbers are being killed or injured in such collisions.

Other threats are fishing nets and ropes that have been lost or discarded, washed up on the shore. When turtles get entangled with nets or twine, it can be fatal.

Sometimes, the weight of the gear is so great it renders them unable to swim to the surface to breathe. Sometimes the turtle becomes so entangled, it is unable to feed and so starves to death.

Pollution and debris in the sea can also lead to the demise of turtles - especially for those species that feed on jellyfish, such as hawksbills. A plastic bag may look like food to such an animal. And ingestion of such trash has sometimes led to the clogging of the digestive system and death.

The Bermuda Aquarium in Flatts has a turtle rehabilitation unit where injured animals are given a chance to recover from life-threatening problems. Qualified staff nurse them back to health - whenever possible - before releasing them back into the wild.

"We have a tiny loggerhead turtle who was stranded and washed up on the shore tangled in Sargassan weed," said Ms Gray.

"And last May we took in a small green turtle which had been hit by a boat and its back was completely fractured open. The staff call it Split Pea and it's healed up well.

"Turtles are slow to mature and they are slow to mend as well after they've been injured like that."

At this week's conference Dr. Godley gave a presentation on the Turtles in the Caribbean Overseas Territories, of which the Bermuda Turtle Project is part and which is funded by the Foreign and Commonwealth Office as well as the UK Department of Environment.

Dr. Godley said: "We are trying to raise money so that we can get people from the other five countries involved to come here and see how this turtle project is being done.

"I think the management and conservation of sea turtles in Bermuda has been exemplary and it's a shame that the nesting populations were lost many years ago."

He stressed that the future prosperity of sea turtles rested on a truly international effort.

To find out more about The Bermuda Turtle Project and sea turtle conservation around the world, call up the web site www.seaturtle.org or contact Jennifer Gray at the Bermuda Aquarium on 293-2727.