Conservationists who helped mana whenua push for new 'no-take' zones in Northland waters are optimistic fishers will stick to new rules.
An Environment Court ruling in November supported a ten-year rāhui around Mimiwhangata Peninsula, as well as Deepwater Cove and Oke Bay in the Bay of Islands.
Another court decision finalising rāhui details was expected in February.
The case challenged the Northland Regional Council's Regional Plan, which did not include fishing controls, and was first publicly notified in 2017.
It used the precedents established in the Bay of Plenty, which ruled that regional councils can protect significant native biodiversity in the sea out to 12 nautical miles.
Karen Field - a committee member for the environmental group Fish Forever - told RNZ: "The rocky reefs around Northland and here in the Bay of Islands, they should be heaving with fish, they should be teeming with fish. And they're just not. And as the years unfold, we'll see that abundance return."
She has been closely involved in the Te Tai Tokerau Environment Court case, and said in particular, she had been concerned about "a very low abundance of crayfish and snapper".
"That means that they're mostly really small. If you've got really low abundance, they all pretty much get caught the minute they're illegal, and so you don't get the really big ones. And it's the big ones that eat the kina. And without the kina being eaten, they just absolutely proliferate and go crazy and mow down all the kelp forests."
Field said Te Tai Tokerau had large patches of "kina barrens".
"It's kind of just like a desert under the ocean really. All the kelp is gone, all the sponges are gone, all the things that create structure and habitat for the little fish in the crabs and the other invertebrates to settle into and grow into, all that cover is gone."
She said it was normal to have opposition when new 'no take zones' were established, but she had seen the sentiment change, in past examples.
"It's one of those things where the really hardcore people who like fishing, they feel as if their life is going to end if they're not allowed to fish absolutely anywhere whenever they want. And so they really fight it hard.
"And then what happens is the no-take area goes in, their life doesn't end, they've still got 99 percent of the ocean to fish in ... and then after a few years as the no-take area gets replenished, you see them all lining up on the boundary because that is the best place to fish. And some of the most hardcore opponents will turn into people who are the best supporters."
Fish Forever was supporting hapū Ngāti Kuta and Te Uri o Hikihiki who first initiated the mahi for the protected areas.
The Environment Court decision also prohibited bulk harvesting of fish around Rakaumangamanga (Cape Brett) to a depth of approximately 100 metres. The area starts immediately north of Maunganui Bay, to end just north of Te Akau (Elliott Bay).
Ngāti Kuta kaumātua Matu Clendon said in a media release: "Decade after decade we saw the mauri of the moana literally disappear.
"We don't want to pass this on to the next generation. We know recovery is possible when the fishing pressure is taken off. Our aim is to provide safety for the breeding grounds to recover, the seaweed forests and work-ups to come back, for the mauri o tangaroa to return in these areas, as once was."
Forest and Bird's Northland conservation manager Dean Baigent-Mercer said: "These kina barrens along Northland's coastline have led to generations of people thinking a depleted sea and almost empty reefs are normal."
The Northland Regional Council has said the rule changes will have significant implications for council as the regulation of recreational or commercial fishing locations was not a function it has undertaken previously.
In a press statement this month, chairperson Tui Shortland said: "This decision will come as a surprise for those used to fishing in these areas and we know many will feel affected by the changes. We are committed to providing clarity around what the new rule changes mean for our community and will be working with tangata whenua and all stakeholders to make sure the new rules are well understood and communicated."
Dr Roger Grace's 2007 research along the Mimiwhangata coast, between Mōkau and Whananaki, revealed 1.74 legal-sized crayfish per hectare, compared with 800 legal-sized crayfish per hectare at Tāwharanui Marine Reserve.
