UP to 37 areas of Scotland's surrounding seas, totalling the size of the country's landmass, are to win special protection in order to support wildlife.
Fishermen and environmentalists are giving a qualified welcome to the move, but some retain reservations, particularly the RSPB.
The Scottish Government yesterday presented a report to MSPs proposing a network of potential Marine Protected Areas (MPAs) to help protect fish nursery grounds, marine wildlife and ecology.
The area MPAs cover extends hundreds of miles out into the Atlantic, the North Sea and waters far north of Shetland.
The move would almost double the 12% of Scotland's seas currently protected, bringing the total area to more than 20% of Scotland's waters, or around 32,000 square miles.
Scottish Natural Heritage and the UK-wide advisory body, the Joint Nature Conservation Committee, have put forward proposals for 33 MPAs.
A further four have also been identified to protect dolphins, whales and basking sharks, while proposals for protecting sandeels would enhance seabird conservation.
However, ministers have yet to decide how to manage MPAs when they come into force in 2016, and what restrictions should be put on fishing and development of renewable energy and oil.
Bertie Armstrong, chief executive of Scottish Fishermen's Federation, made clear that fishermen believed it was vital the MPAs were managed sensibly.
He said: "We have long recognised the protection requirements of the environment we work in every day. We have insisted from the start scientific evidence and common sense be used in determining the size and number of protected areas and what, if any, practical measures are required in each individual case.
"It is absolutely essential science guides the process, which must serve the requirements of the marine environment and of sustainable harvesting of sea food.
"If MPAs in Scottish waters are properly organised, the objectives should actively support each other. We are committed to that."
However, Stuart Housden, director of RSPB Scotland, regarded the proposals as failing to take account of the plight of seabirds in the MPAs.
He said: "[This] announcement, while a step in the right direction, is a massive missed opportunity. Despite Scotland being globally important for these species, seabirds have been almost completely marginal- ised in the identification of Scotland's new Marine Protected Areas
"These proposals offer precious little protection for Scotland's seabirds – iconic species like the puffin, razorbill and kittiwake."