Ministers asked SNH to investigate the possible aims, powers and running costs of a marine park off Scotland's coast.

SNH will report to ministers next March with plans for a new park, which should be created by 2008.

The public are being encouraged to give their views through an interactive message board on SNH's website.

The idea of a marine national park to protect Scotland's dolphins, whales, basking sharks and sea birds was first mooted in February 2000.

SNH chairman John Markland said it was a very exciting opportunity for Scotland to raise awareness of its rich and diverse coastal and marine heritage.

We are very much starting with a blank canvas John Markland SNH chairman

"National park designation is a great accolade and the selected area should benefit from an increased profile and the strengthening of management and associated resource inputs," he added.

"We are very much starting with a blank canvas and would encourage anyone with views on this issue to contact us and contribute their ideas over the coming months."

'Variety of species'

The new national park would be set up under the existing National Parks (Scotland) Act 2000, with the same four broad aims as the country's existing parks.

These are:

• Conserving and enhancing the natural and cultural heritage

• Promoting the sustainable use of natural resources

• Pushing access, enjoyment and understanding

• Driving the economic and social development of local communities.

Environment Minister Ross Finnie said Scotland's coastline and seas were a valuable natural, cultural and economic resource.

He added: "I would encourage as many people as possible to get involved in the debate which will enable us to find out more about our marine environment and indeed the variety of species which depend on it."