60 square miles of Lyme Bay will be off limits to scallop dredgers
A ban on fishing in one of Britain's "richest" marine environments is to be implemented to protect its wildlife and seascape.
About 10% of Lyme Bay off Dorset and East Devon is to be permanently closed to scallop dredging and bottom trawling from July, Defra has announced.
The bay's reefs are home to an abundance of sea life including rare sponges, corals and starfish.
Conservation groups have welcomed the ban but some local fishermen are angry.
Environment Secretary Hilary Benn said: "Lyme Bay is one of Britain's richest environments, and the measures we have announced today will protect the reefs and the wildlife that depends on them from the most damaging fishing methods."
The fishing ban will cover 60 square nautical miles of Lyme Bay, from West Bay in Dorset to Beer Head in Devon.
The area will be off-limits to fishing boats which drag nets along the seabed. Wildlife groups had argued this was damaging the environment.
Dr Jean-Luc Solandt of the Marine Conservation Society said: "In the end, most fishermen and conservationists want the same thing - sustainable fishing which has limited impact on the marine environment."
Fishing organisations said they were furious and felt betrayed that a gentleman's agreement to allow them to fish in certain parts of the bay and leave others alone had been rescinded by the Government.
Nick Prust from the South West Inshore Fishing Association said: "It's catastrophic for inshore fishing. We feel let down, disappointed and disgusted."
Jim Portus from the South West Fish Producer Organisation said: "I'm devastated, it will mean a £3m annual loss for the local economy. It's not a happy day for inshore fishing."
More marine reserves are likely to be announced in the forthcoming marine bill.