UNDERWATER surveys have begun to determine the cumulative impact of dredging and dumping, following criticism from green groups that the Government was ignoring the problem.
The Civil Engineering Department spent $1 million last month photographing more than 400 local underwater sites with remote cameras, and will repeat the exercise every three months.
The dredging and dumping has destroyed coral and is feared to be driving fish away.
Green groups welcomed the underwater surveys, but remained sceptical they were being carried out too late.
Lisa Hopkinson, of Friends of the Earth, said: ''Of course it is useful - the clearer the picture you've got of what's happening on the seabed, the better - but there has to be some purpose for the monitoring. Otherwise it's an historical archive.'' Jo Ruxton, of the World Wide Fund for Nature, said: ''I can't help thinking it's all come a bit late. What's the point of finding out what's there as they destroy it?'' John Massey, who heads the Civil Engineering Department's fill management committee, revealed the surveys were in response to concern that the Government was monitoring only individual dredging sites and not the territory-wide impact.
He agreed the work ideally should have been done before dredging started, but said the dredging work made money available to fund the surveys.
''If you looked anywhere else, you would find that you don't get detailed specific documentation until there's a need for it. And the people who tend to do that documentation are the proponents of dredging,'' he said.