|Coast hope the "no take zone" will allow the sea bed to regenerate|
The "no-take zone" - banning fishing in a small area of Lamlash Bay - comes after a long-standing local campaign.
Conservationists from The Community of Arran Seabed Trust (Coast) lobbied ministers for the marine reserve, which has now been agreed.
Environment Secretary Richard Lochhead will announce plans in Lamlash later.
Coast believes the fishing ban will help protect the local fish and shellfish populations as well as the maerl seaweed beds, which support diverse marine life.