Baie ny Carrickey in Port St Mary will be closed to the majority of fishing from Friday.
For King and Queen Scallops that's going to be in place for 20 years, although that will be reviewed after five years.
It'll also be closed to fishing for crabs and lobsters, for three years, except for the Baie ny Carrickey Crustacean Fishery Management Association and 'hobby pot' fishermen.
The Department of Environment, Food and Agriculture says the move follows a public consultation over the summer.
DEFA Minister Phil Gawne admits the move hasn't proven popular with everyone, though:
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