Ancient maerl beds smothered in algae caused by sewage pollution

CORNWALL'S irreplaceable marine habitats are at risk of disappearing for ever because they are being smothered by algae caused by sewage pollution, experts have warned.

- by OLIVIER VERGNAULT

Marine scientists and conservationists said they had been shocked to discover ancient maerl beds off St Mawes, on the Roseland peninsula, choked with algal growth because of the poor water quality.

The UK Maerl Forum saw scientists from across the UK meet in Cornwall for the first international event of its kind focusing on maerl, a collection of coralline red algae species forming a unique habitat which can be thousands of years old.

Cornwall possesses globally significant areas of maerl, which forms chalky nodules which are very fragile and very slow-growing, by only a millimetre per year.

Reporting on a dive to inspect the maerl beds Matt Slater, marine conservation officer at the Cornwall Wildlife Trust, told the gathering: “It was a shocking sight.

“The area, previously purple and beautiful, is now covered with a thick layer of brown, fluffy algae.

“We've surveyed here regularly for the past eight years and I’ve never seen the maerl beds looking like this. It's a massive concern and shows, yet again, why it's urgent that we do all we can to improve water quality in the Fal estuary.”