He said the wreck of the navy frigate HMNZS Canterbury was resting inside the designated rahui area.
"That's a real drawcard for the bay. It brings in the fish and then the dolphins and the boaties," he said.
"Maunganui Bay has always been an important customary fishing area for our people. We consider that this further temporary closure will assist with regeneration of fish stocks in the area, not only for customary purposes but also for the benefit of the wider community."
David Scranney, spatial allocations manager at MPI, said kina were excluded from the rahui because information showed they are abundant in Maunganui Bay.
Fishery officers will continue to patrol and enforce the temporary closure. Fines up to a maximum of $100,000 apply to anyone caught breaching it.
Members of the public are encouraged to call 0800 4 POACHER (0800 476 224) if they see anything suspicious at Maunganui Bay, or elsewhere.