Westcountry beaches have come top for water quality for the third consecutive year, a Marine Conservation Society (MCS) survey has revealed.

In total, 139 of the region's 192 tested beaches earned the top "recommended" standard in the MCS 2008 Good Beach Guide.

But this figure is down by about 10 per cent on last year's number of 155.

The latest bathing water tests, conducted from May to September 2007, coincided with what was thought to be the wettest British summer on record.

MCS blames the drop in water quality largely on an increase in storm related pollution caused by the wet weather.

Three tested beaches in the region failed to meet minimum European standards.

These were Mothecombe in the South Hams, Summerleaze beach in Bude and Instow in north Devon.

Thomas Bell, MCS coastal pollution officer, said: "These latest MCS results buck the long term trend of cleaner bathing water but we're pinning the blame squarely on last summer's exceptionally bad weather.

"Heavy rain sweeps pollutants like raw sewage, street debris and animal waste directly from the land into rivers and the sea.

"Not all beaches are affected but the problem for swimmers is knowing when and where this has happened."

The total number of UK beaches with excellent water quality dropped by 10 per cent in this year's Good Beach Guide, the biggest fall in 21 years.

Of 779 beaches tested, 443 received a top rating, compared with 495 last year.