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OPINIONSocietyApril 12, 2023

The Hauraki Gulf is stuffed – and there’s a simple fix being wilfully ignored


The Hauraki Gulf, the big blue backyard to Auckland enjoyed by more than a million people, is suffering a catastrophic collapse of biodiversity. A network of marine reserves is the only way to save it, writes Alex Stone.

Imagine if New Zealand’s response to Covid – or to any other crisis for that matter – ignored a clear and unambiguous consensus of scientific recommendation. And instead chose to follow a long, slow (years-long) route that we know will not work. Even when we have the proof for this right here, in our own big blue backyard. And a discussion on foundations that have not been defined.

The crisis we’re talking about is the properly and fully acknowledged collapse of biodiversity in the Hauraki Gulf. The figures are stark; and have been confirmed by ongoing scientific research; and published regularly over 20 years by the State of our Gulf reports.

Put simply: the Hauraki Gulf is stuffed. And we’re not going to fix it this way.

The solution is equally simple: a network of marine reserves covering at least 30% of the gulf. Just like our Covid response plan, the design of this network should be based on four clear principles:

  1. Each reserve should be big enough to be a functioning ecosystem in itself (so far none in the Hauraki Gulf are)
  2. All the different habitat types should be represented (for example, surf beaches are a habitat too)
  3. There should be more than one reserve of each habitat type
  4. The reserves should be interlinked (by clear passages, or tidal or sea currents, say)

This is consistent with the cornerstone of contemporary conservation science, which views the restoration of entire habitats as the way to go. This also accepts the multivariate potentialities of the contribution of science – plus other considerations such as the right to life for all species and the ecosystems services they provide. 

The government and the Department of Conservation have some explaining to do. For at the UN conference on biodiversity in Montreal in December last year, the nations of the world agreed as an urgent priority the establishment of 30% of oceans and land as protected areas.

And on March 4 this year, Rena Lee, UN ambassador for oceans, brought down the gavel on the High Seas Treaty, which also aims to help place 30% of the seas into protected areas by 2030, to safeguard and recuperate marine biodiversity. “The ship has docked,” she said, echoing relief that 10 years of negotiations had been successfully concluded.

New Zealand signed up to both.

In New Zealand we already have 30% of our land area in conservation estate. But at sea and in freshwater conservation our record is dismal. We’ve got catching up to do – but it should be easy, given we already have a terrestrial head start.

An octopus and a nudibranch mollusc in the waters of the proposed NW Waiheke Hākaimangō-Matiatia Marine Reserve (Photos: Shaun Lee, supplied)

The Hauraki Gulf, the big blue backyard to Auckland enjoyed by more than a million people (and in the great majority for reasons other than fishing), is suffering a catastrophic collapse of biodiversity. This is undisputed; and accepted by everyone, including customary, recreational and commercial fishing people. 

Indicative of the accelerating ecological deterioration of the Hauraki Gulf, from an estimated virgin (unfished) biomass there has been:

57% decline in key fish stocks

67% decline in seabirds population

76% decline in kōura (crayfish)

83 % decline in tāmure (snapper)

86% decline in arara (trevally)

86% decline in mango (all shark species)

97% decline in whales and dolphins

[Source: State of our Gulf 2020]

This collapse has been caused by overfishing, both commercial and recreational. 

In fact, in the inner gulf (south of Hauturu o Toi/Little Barrier Island), the recreational take of tāmure/snapper is greater than the commercial take. 

Looking at the map of commercial fishing regulations in the entire Hauraki Gulf Marine Park (which extends out beyond the Coromandel), it’s clear that every inch of it has some restriction in place (below left).

Commercial fishing is restricted in most of the gulf (left), but recreational fishers have open access to around 95% of it (right)

There’s a tragically circular economy going down in this, too. According to the 2020 State of our Gulf report, the annual commercial harvest of pilchard from the Hauraki Gulf is 376 tonnes. All of the commercial pilchard take in New Zealand is marketed as bait for recreational fishers. We even import pilchards as bait from three other countries to meet this “need”. We’ve known for decades that a cause of mortality of kororā (little blue penguins) in the Hauraki Gulf, for whom pilchards are an important food source, is starvation. And recently there’s been much concern about signs of malnutrition in snapper (the white milky flesh). 

By contrast in the maps, recreational fishers have open access to around 95% of the gulf. The map shows tiny blue areas of marine reserves, plus the nominally restricted area of cable and shipping channels.

This urgent crisis has been formally debated since 2012 when the SeaChange project, jointly organised by the Auckland and Waikato Regional Councils, began. The SeaChange report released in 2017 recommended, among other measures, a network of  new marine reserves and other protected areas. DOC’s own scientists and every marine biologist agreed.   

In June 2021 DOC released a response to the SeaChange proposals, a document called Revitalising the Gulf.

It has no new marine reserves. 


It does suggest possible extensions to the already tiny Goat Island and Hahei marine reserves.

Instead, Revitalising the Gulf offers 13 new experimental “High Protection Areas” (HPAs) based on customary take. These are a regulatory tool yet to be legislated and are based on foundations yet to be defined. For example, what tonnage of take? What species (what fish and shellfish? Will marine mammals and seabirds be part of the take)? What methods (customary or contemporary)? What will be the hierarchy of take when there are competing and overlapping iwi interests, as is the case in most of the Hauraki Gulf?

The first of these HPAs will only be in place in late 2024. After parliament has passed a new law that will facilitate their creation. And there appears to be no set timeline for the discussion on the definition of customary take. It’s hinted that each area will have its own unique discussion about this. 

The HPAs are “limited take” areas which we know do not work. This is proven by the Poor Knights Islands, which were a limited take zone for over 50 years from the 1920s to 1981, with no significant improvement. It was only after they became New Zealand’s second marine reserve in 1981 that they blossomed into the world-famous dive destination they are today. Similarly, Mimiwhangata in Northland has been a limited take area for 50 years, monitored with no real improvement for most of that time by the late great marine biologist Roger Grace. Almost the entire Hauraki Gulf is in effect a limited take area, with only 0.03% in marine reserves. And how’s that working out? 

Even with the experimental HPAs in place, less than 5% of the gulf will be protected. Plus a further 6% of shipping channels and cable zones. Though the first of these allow dredging, and neither is designed or placed as a functioning marine reserve. 

Revitalising the Gulf also ignores the only new marine reserve proposal in the Hauraki Gulf for the past 20 years – the NW Waiheke Hākaimangō-Matiatia Marine Reserve. 

In 1,300 submissions about this proposal, 93% from around the country were in favour. And 95% of the Waiheke community. And 70% of all submitters who identified as Māori. And the officially designated mana whenua iwi organisation the Ngāti Paoa Trust board. These figures are historically high and unprecedented. (Almost all of the existing 44 existing marine reserves in New Zealand faced significant opposition and were 50:50 calls.) 

So it’s clear the people of New Zealand recognise the need to act. And fast.

The proposed NW Waiheke Hākaimangō-Matiatia Marine Reserve

It is proven beyond a shadow of doubt that marine reserves are far and away the most effective marine protected areas. They hold 670% more biomass than unprotected waters and more than double that of the next most effective MPA (Marine Protected Area – of which there are five types). 

Put simply, this is more than six times as many fish in the sea. We will all benefit from this – including recreational fishers, for marine reserves have no fences, and all have a positive spill-over effect. Being in an area of tidal stream, the Hākaimangō-Matiatia Reserve will have an ongoing positive effect over a far greater area, as larvae and small fish will be dispersed far outside the reserve.

Marine reserves are also of enormous benefit economically. A paper published last year by Zoë Que and other University of Auckland marine scientists showed that the benefits from one species alone (tāmure/snapper) from one tiny marine reserve (Goat Island, 480ha) amount to more than $10 million annually. 

They also help seabirds, marine mammals, seaweeds and all other underwater species recover.

Revitalising the Gulf has chosen to be wilfully blind to all this. 

And so have some lobby groups for recreational fishers. Who we know are a tiny – and declining – minority. The annual Active NZ survey has tracked recreational fishers as a percentage of the adult population (and defined as a person who may fish at least once a year) going from 15% in 2017 to 12% in 2021.

It’s curious that ginger groups for recreational fishing have chosen to actively resist the one proven thing that will help them. And all of us. The recent article by Legasea’s Sam Woolford on the milky-fleshed snapper asks for a change in the habits of everyone else – except recreational fishers. 

It’s curious too that we and our government can do so well in response to another crisis with our world-leading Covid response; and yet do so poorly in the realm of essential marine conservation.

We can do better. We must do better. For the sake of our mokopuna.

Alex Stone is the Waiheke Island-based founder of Friends of the Hauraki Gulf. He has sailed, researched and written about the Hauraki Gulf for over 30 years.

Keep going!