Giant logs washing up around the coast of Bermuda may be doing unseen damage to the coral reefs surrounding the Island.

Around a dozen logs have been reported either in shallow water or washed up on beaches during the past three weeks. The latest log was found at a beach in Tucker?s Town on Monday and is thought to be the same log that was earlier spotted in the water near the lighthouse at St. David?s.

A warning has been issued to mariners to be alert for more of the floating, bits of lumber ? some up to 80 feet long ? which pose a danger to all vessels.

But of equal concern is the danger the logs present to the fragile reefs fringing the shallow coastline areas of the Island.

At low tide it is quite possible the lumber could crash against the reefs causing untold damage to the ecology, and there are also worries about the leaching of toxins such as creosote from the logs, which appear to be treated supplies of timber destined for use as telegraph poles.

The source of the logs is still unknown, although it is suspected they rolled off a passing container ship and were carried by ocean currents for months before arriving at Bermuda.

?Clearly any large bit of flotsam that goes across the reef has the potential of colliding with and damaging the reef,? said Jack Ward, Director of the Department of Conservation Services.

?It depends on how deep these floating objects are. I understand they are two feet in diameter, so if they come across the reef at low tide they certainly could cause damage.?

Avoiding the occurrence of such damage is almost impossible, however, as there is no way to predict when the logs might appear.

Mr. Ward said: ?The only way to minimise the damage is to collect them and contain them. There is not much more that can be done.

?And because they are treated pieces of lumber there is the potential of them leaking toxins. Out at sea, any toxins leaking would be dissipated quite quickly. However, these are not good things to have out in the environment.?

Mr. Ward thinks it unlikely that it could ever be proven that a particular log has crashed into the reef and caused damage, unless the incident was viewed first-hand.

The priority for dealing with the logs is to secure them as quickly as possible so they do not drift back into the open water.

A variety of agencies have been involved in dealing with the logs. A number of the logs have been pulled from the water and stored at Dockyard. Others have been dragged ashore and cut up for easier disposal.

The mystery of where the logs have come from is still be investigated by world famous beachcomber Curtis Ebbesmeyer in Seattle, who has been given details of identifying tags found on some of the logs.

Identifying tags on the logs have included the wording ?JHB DFC E05 E04 and JH Baxter? and there is a strong indication the logs originated in Oregon.

A log found at Nonsuch Island had a yellow tag with the identity ?#14258 Niedint?. There is a company in Ashland, Oregon called Niedermeyer Intertrade Corp. which supplies wooden poles.

The newly discovered log at Tucker?s Town was expected to be chopped up and taken away. Anyone finding a log washed up or floating in the water should report it to Harbour Radio.