The moves were announced by Rhona Brankin

"For it to continue to flourish we need to protect and improve shellfish waters for an expanding industry - that is what we mean by sustainable development.

"The consultation launched today identifies over 80 possible new areas, potentially increasing almost four-fold the number of designated waters."

The minister said the sites had been chosen after discussions with the Scottish Environment Protection Agency, the three water authorities and the industry.

She went on: "It is vital to protect the water quality to ensure that the industry does not have to tackle the pollution caused by others.

'Environmental protection'

"The quality of our water environment is a key marketing factor in the promotion of the industry's products world-wide.

"Increasing the number of waters designated as shellfish waters will ensure that the vast majority of Scotland's shellfish growing is carried out under strict environmental protection."

She said the move also demonstrated the Executive's commitment to "supporting and strengthening this country's shellfish industry".

Under the EC Shellfish Waters Directive, member states have to protect waters which sustain shellfish life to improve the quality of the catch.

The proposals to increase the number of designated waters, currently 33 in Scotland, was also based on data from the Fisheries Research Service.