Hauraki Gulf / Tīkapa Moana / Te Moananui-ā-Toi. State of the environment report 2026

Executive summary

Tīkapa Moana / Te Moananui-ō-Toi / the Hauraki Gulf is a place of deep significance. For mana whenua, it is not separate from who they are, but part of their identity, whakapapa, and existence. For many others, it supports livelihoods, recreation, and everyday experiences. It is also one of the most heavily used and impacted marine environments in Aotearoa.  

This report brings together what we know about the state of our Gulf, with a focus on how it has changed over the past three years. It assesses progress toward integrated management and the priority issues identified by the Forum, including marine habitats, water quality, fisheries, biodiversity, and biosecurity. Independent research commissioned by the Forum values ecosystem services provided by the Gulf at $5.14 billion a year. Without more ambitious investment from central government, that value will diminish and the ecosystem will fail. Coordinated action is emerging, but it remains mana whenua and communities – using their own time and resources – who continue to defend the Gulf.

What has changed

Over the past three years, activity across the Gulf has increased and become more coordinated, including:

• establishment of 19 new marine protected areas
• fisheries closures, changes in fisheries management and ongoing reform, including closure of the inner Gulf to commercial and recreational kōura harvest from April 2025
• whole-catchment restoration increasingly coordinated across the Gulf, including largescale riparian fencing and planting projects reconnecting wetlands to the coast
• restoration, protection, and monitoring led by mana whenua alongside communities and agencies
• more rigorous monitoring and analysis on marine biosecurity following the spread of exotic Caulerpa. 

Together, these actions signal a shift from describing decline to actively responding to it.

There is also greater alignment between iwi, agencies, and communities. Ki uta ki tai, or catchment-to-coast approaches, are becoming more common, reflecting a clearer understanding that the health of the moana is shaped by what happens on land and in freshwater systems.

What remains under pressure

Despite this progress, the Gulf remains under significant, and in some cases increasing, pressure.

Sediment and contaminants from land-based activities continue to affect water quality and seafloor habitats. Auckland Council assessments found only 2% of monitored estuary sites in excellent condition. Every monitored estuary showed at least moderate impacts from excess land-derived sediment. The Firth of Thames was declared a degraded water body in 2025, with the Waihou and Piako among New Zealand’s most nitrogen-loaded rivers.

Marine biodiversity remains under stress, with ongoing loss or degradation of habitats that support the wider food web. Some fish stocks and shellfish populations continue to show decline or slow recovery. This is evident in the request from three iwi within Pou Rāhui, Ngāi Tai Ki Tāmaki, Ngāti Tamaterā and Ngāti Paoa, for two-year extensions to their existing Section 186A Applications with Fisheries New Zealand supporting rāhui over shellfish species within their rohe.

New pressures are also emerging. The spread of exotic Caulerpa and the increasing frequency of marine heatwaves are affecting ecosystems in ways that are not yet fully understood, but already frightening.

For many people, these changes are experienced over time in what is caught, what is seen, and what is no longer there.

Climate change is intensifying the system

Climate change is no longer a future pressure. It is already influencing the Gulf.

Warmer waters, more frequent extreme weather events, and changing ocean conditions are increasing stress on ecosystems and compounding existing pressures. In some areas, change is occurring faster than recovery.

Marine heatwaves offer a clear illustration. During heatwave conditions pakahā / fluttering shearwater are forced to travel further to find food, with foraging trips doubling in length, reducing breeding success and leaving adults and chicks in poorer condition.

Response is increasing, but not yet at scale

Action across the Gulf is more visible, coordinated, and collaborative than in the past. Mana whenua continue to uphold their responsibilities as those with whakapapa to the rohe, exercising mana and rangatiratanga through efforts to restore and revitalise Te Tīkapa Moana / Te Moananui-ā-Toi. Community involvement is growing. Investment from philanthropy, policy change, and collaboration are enabling a broader range of responses.

While actions are increasing, the overall picture remains uneven.

With much of the directorial effort landing relatively recently, it is too soon to see measurable outcomes from this investment and decision-making. It will need to translate into consistent, system-wide improvement at the scale required for positive impacts to be explicitly seen.

The key issue is not whether effort is underway, but whether it is occurring at the pace and magnitude needed for lasting regeneration. For example, the designation of High Protection Areas in 2025 and manual removal of kina can kickstart recovery, but this requires reduced fishing pressure across the wider environment, so that natural predators like tāmure and kōura can keep kina in check, and healthy, productive ecosystems can be sustained long term.

Overall state of the Gulf: Mauri heke / Under pressure

Te hurihanga tai – a turning tide.

Three years ago, the last report found a system under pressure, with water quality, habitat condition, and key species already degraded or variable. This report finds the same indicators, but the pressure has not eased. It has compounded.

At the same time, there are visible signs of response, including restoration activity, closures in line with the Hauraki Gulf Fisheries Plan, and localised recovery in some areas, such as the return of kiwi to Waiheke, and the reestablishment of tīeke / saddleback on Rakitū Island after more than 50 years.

The direction of change is not yet fixed. There is still time to restore mauri, but the window is narrowing. With a warming climate and unpredictable weather systems setting in, every lever within our control must be pulled to regenerate and maintain a resilient system, or the next report will be painting a much starker picture.

Looking ahead

The response is becoming more deliberate, better equipped, and broader in reach, but the outcome is not guaranteed.

The future health of the Gulf will depend on whether current efforts are accelerated, aligned and sustained over time.

It will require continued partnership between mana whenua, agencies, communities, and decision-makers, and commitment to acting at the scale needed to support recovery.

The science and mātauranga generously provided over the lifetime of the State of our Gulf reporting has been clear and robust throughout. We have the information we need, we just need to get on with it; for the moana, for the mauri and for us all.

Hauraki Gulf Forum, July 2026

See also

Previous years' reports

Hauraki Gulf Forum