New restrictions will apply when the Marlborough Sounds re-opens for blue cod fishing next April, a year earlier than planned.
The fishery was closed in 2008 after concerns about rapidly declining numbers of blue cod.
Fisheries Minister Phil Heatley says new management measures will ensure the fishery's long-term sustainability.
A restricted season will be introduced from 20 December to the end of August.
Bag limits will be two cod per person, per day. Fish must be between 30 and 35 centimeres long, and there will be a no-take zone around Maud Island.
Recreational fishers welcome the reopening the Sounds to blue cod fishing but say some new rules are too tough, including the length of fish.
Marlborough Recreational Fishers Association president Tony Orman says that rule will mean over-fishing as people try to catch the right-sized cod.