Conservationists have questioned claims that a temporary causeway at Somerset Bridge may have actually benefitted the environment.

The National Trust's marine environmental committee has responded to a Government theory that tonnes of boulders used to fill in the waterway could have become a marine wildlife haven.

Committee chairman Wayne Carey said he would query any suggestion that fish were breeding around the rocks, without proof from an expert.

"We don't know whether the fish are there because they can't get past the structure or maybe because people are feeding them,'' he said.

"I don't know whether there is direct evidence that fish are breeding, I would question that.'' He was speaking after Works and Engineering Minister C.V Jim Woolridge indicated the marine environment, save for some coral damage, appeared to have escaped any damage.

Engineers working on the renovations to the landmark drawbridge said they had seen schools of fish around the boulders and it was thought that the fish could be breeding around the site.

The temporary causeway -- which is expected to remain in position until the middle of July -- was built to take traffic around Somerset Bridge during the repairs.

Mr. Carey said the committee had not been monitoring the work but had met with Works and Engineering staff last week.

Their concerns now focused on the removal of the causeway -- which was promised would be completely removed once the bridge was reopened -- and all the spoil.

He said Works and Engineering staff were due to inform the marine and environmental committee of their intended method in the near future.

"It will be important the way they do it,'' he said.

GOVERNMENT GVT TRANSPORTATION TRA