Scientists in Plymouth have discovered a massive patch of algae stretching across the sea from Cornwall to Devon.

Plymouth Marine Laboratory scientists detected the large bloom covering an area from the Lizard across to Salcombe.

The bloom, which is likely to discolour the sea, consists of vast numbers of harmless microscopic plants called Skeletonema and poses no threat to other marine life, according to experts. Dr Peter Miller, earth observation scientist at the laboratory said: "Skeletonema is a beautiful microscopic plant that, given the right conditions, reproduces rapidly to cover large areas of coastal seas.

"Over the winter, nutrients have built up in the sea and the windy weather we have experienced recently has stirred them up to the surface. Combined with the now calmer conditions and bright sunny days, everything slotted into place to enable this plant to reproduce and form a large bloom."

Claire Widdicombe, a plankton ecologist at the laboratory, said:

"This species all but disappeared from Plymouth Sound for many years and its early appearance this year is all the more unusual."