Fishing has been banned for two years in Maunganui Bay in the Bay of Islands, which includes Deep Water Cove - final resting place of the former Navy frigate Canterbury.
The closure, ordered by the Ministry of Fisheries, starts on December 1 and lasts for two years.
The ban applies to all
fish, aquatic life and seaweed, with kina the only exception.
Rawhiti hapu Ngati Kuta and Patukeha placed a rahui over the bay in March last year amid concerns over depleted fish stocks.
Yesterday's announcement adds official clout to the rahui, and the prospect of stiff penalties for those caught fishing in the bay near the tip of Cape Brett peninsula.
HMNZS Canterbury, New Zealand's last steam frigate, was sunk in Deep Water Cove in November 2007 and has since become a Mecca for divers and marine life.
The Ministry said kina were excluded from the ban because they were abundant in the area.
The closure has been welcomed by the bay's diving fraternity.
Northland Dive's Shane Housham - who began the campaign to bring the Canterbury to the Bay of Islands - said the closure would protect the wreck from being fouled by hooks and lines.
His business gave diving clients a chance to sign a submission calling for a fishing closure and not one had been against it, he said.
Patukeha spokesman Richard Witehira said the hapu would have been just as happy with a voluntary ban - but a high-profile area like the Bay of Islands attracted a lot of visitors who did not always respect or understand the rahui.
It was unfortunate the closure had to be made official, "but that's probably the way things are these days". The rahui was prompted by people fishing directly over the wreck within weeks of the Canterbury's sinking, tangling lines and creating diving hazards.
The original idea was a 200m exclusion zone around the wreck but closing the whole bay gave fish a place to breed and spread out into the rest of the Bay of Islands, he said.
"That's got to be good for everyone," he said.
The bay will be patrolled by fishery officers enforcing the closure, with a maximum fine of $100,000 for anyone caught breaching it.
