Image copyright Keith Bremner Image caption Achmelvich Beach in the north-west Highlands (rated excellent)

Water quality at 17 Scottish beaches have been classed as "excellent" against new, much stricter European standards.

The Scottish Environment Protection Agency (Sepa) said 80% of Scottish beaches passed the standard as "excellent", "good" or "sufficient".

However, 17 beaches are now rated as "poor" under the new system.

Sepa measured the quality of water at 84 "officially designated bathing waters" across Scotland.

Many beaches likely to have good water quality - for instance in the Western Isles - are not officially designated and so the pollutants are not monitored there.

The new EU classification system includes four years' of monitoring data which Sepa said provided a "more consistent picture" of water quality.

Image copyright Kevin Allibone Image caption Machrihanish beach in Argyll and Bute (rated excellent)

Scotland's best and worst beaches Rated "excellent" Rated "poor" Aberdour (Silversands) Cruden Bay Achmelvich Dhoon Bay Broughty Ferry Eyemouth Crail (Roome Bay) Fisherrow Sands Culzean Girvan Dornoch Heads of Ayr Dunnet Kinghorn (Harbour Beach) Elie (Ruby Bay) Monifieth Fraserburgh (Philorth) Mossyard Ganavan Nairn (Central) Gullane Nairn (East) Kingsbarns Portobello (West) Largs (Pencil Beach) Prestwick Loch Morlich Rockcliffe Machrihanish Sandyhills Pease Bay Stonehaven Seacliff Yellow Craig

Scotland's 'best and worst' beaches Rated "excellent" Aberdour (Silversands)

Achmelvich

Broughty Ferry

Crail (Roome Bay)

Culzean

Dornoch

Dunnet

Elie (Ruby Bay)

Fraserburgh (Philorth)

Ganavan

Gullane

Kingsbarns

Largs (Pencil Beach)

Loch Morlich

Machrihanish

Pease Bay

Seacliff Rated "poor" Cruden Bay

Dhoon Bay

Eyemouth

Fisherrow Sands

Girvan

Heads of Ayr

Kinghorn (Harbour Beach)

Monifieth

Mossyard

Nairn (Central)

Nairn (East)

Portobello (West)

Prestwick

Rockcliffe

Sandyhills

Stonehaven

Yellow Craig

Thirty-eight beaches are also rated as "good" and 12 as "sufficient". Read the full profiles for each beach. Source: Sepa

The new classifications will be displayed at the beaches from May until mid-September.

This summer, Sepa said it would also be extending its network of electronic signs - which provide daily real-time water quality information - to six new beaches.

Image copyright Hamish Hastie Image caption Pease Bay, in the Borders (rated excellent)

Image copyright Walter Baxter Image caption Pease Bay in the Borders (rated excellent)

Image copyright Fiona Clark Image caption Dunnet Bay in Caithness (rated excellent)

The agency is also preparing improvement plans to help poorly-rated beaches with the aim they would meet at least the "sufficient" standard by 2020.

Calum McPhail, Sepa's environmental quality manager, said: "We understand that some local communities will be disappointed, as we are, that 17 bathing waters have been rated as having a 'poor' EU classification, and many will be concerned when the new classifications are displayed on these beaches for the first time this month.

"It is important to remember that a 'poor' classification does not necessarily mean that water quality is continually poor, and in many cases this is due to historic episodes of reduced water quality following heavy rainfall. These are still fantastic beaches to visit."

Mr McPhail added that Scottish bathing waters had been increasing in number and quality since monitoring began in 1988.

VisitScotland said marine recreation and tourism expenditure was worth an estimated £3.7bn a year to Scotland.

A spokesman added: "We are pleased that the vast majority of bathing waters are classified as sufficient or above, while 65% have an excellent or good classification.

"It is very disappointing, however, to hear that the water quality at some beaches have not met Sepa bathing water standards and we will be discussing the potential impact this could have on tourism with the organisations involved."

Image copyright Keith Bremner Image caption Achmelvich Beach in the north-west Highlands (rated excellent)