About 10 per cent of Lyme Bay from West Bay to Beer Head will be permanently closed to scallop dredgers and bottom trawlers which drag nets along the seabed, to safeguard the area’s rich marine life and habitats.
Lyme Bay is home to world-renowned reefs as well as important species including pink sea fans, sunset cup corals and several rare sponges.
After public consultation and a full assessment of the impacts, the government has ordered that the area be closed from early July.
Fishing using nets nearer the surface or static nets and lines will still be allowed, as will diving for scallops, scuba diving and sea angling.
Environment Secretary Hilary Benn said: "Lyme Bay is one of Britain’s richest marine 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 environmental benefits will be huge, and species under threat will be able to recover and thrive."
Marine and Fisheries Minister Jonathan Shaw said: "A lot of work has gone into assessing the impacts, and this is just the kind of major decision about managing and protecting our seas that the government’s Marine Bill will help us take in future.
"The decision to protect Lyme Bay’s wildlife shows that we are committed to protecting the marine environment. I want to work with people all around our coast to establish a national network of marine conservation zones to help protect the richness and diversity of life in our seas."
The recovery of species and habitats in the closed area, as well as social and economic impacts, will be monitored closely.
Ministers Act to Protect Lyme Bay Sea Life
UK - Ministers have banned damaging types of fishing in 60 square nautical miles of sea off the South West coast to protect threatened sea life.