Motukorea / Browns Island is a visual icon of the Hauraki Gulf, but beneath its green slopes lies a history of heavy modification. Farmed for the better part of the last century, the island’s terrestrial habitats are now dominated by Kikuyu grass—a thick, aggressive mat that chokes out diversity and leaves little room for native flora to gain a foothold.
Recently, we began work at the southern tip of the island with a specific goal in mind: creating roosting and nesting habitat for endangered shorebirds. To do this, we sprayed back the Kikuyu grass, the first attempt with brush cutters was not successful.
As the grass died back, weeds quickly sprung up in the newly cleared earth. But while I was out there clearing these weeds, I looked closer at the ground and found something surprising.
Hidden gems in the weeds
Among the weeds were the unmistakable seedlings of native trees. I found two different types of Coprosma and a few young Karo plants. This sparked a bit of an ecological mystery. Where did they come from?
Aerial image of Motukorea in 1940. Source Geomaps / Auckland Council.
“There is no evidence of the island ever being forest-clad. It was cultivated for kumara and taro in the 1820s when visited by Samuel Marsden and RA.” – Esler, A. E. (1993). Plant Life of some Inner Hauraki Gulf Islands. Horticulture in New Zealand (Journal of The Royal New Zealand Institute of Horticulture), 4(2).
It is highly unlikely that these seeds survived more than 200 years in the soil bank. The most logical transport method is avian delivery—birds flying in and dropping seeds.
The unusual suspects
Usually, when we talk about forest regeneration in New Zealand, we look to our native pollinators and seed dispersers, like the Kererū or the Tūī.
However, on Motukorea, native fruit-eating birds are scarce. It is rare to spot a Tūī on the island and I can’t recall ever seeing a Kererū. So, who is doing the reseeding?
The island is, however, home to large populations of non-native birds like Feral Rock Pigeon, Starling and House Sparrows.
Feral rock pigeon on Motukorea
A novel restoration method
The theory is simple but fascinating. The clearing of the Kikuyu created a roosting and feeding area. As weeds fruited on the flats, the Pigeons and Starlings flocked in to feed. While they were there, they deposited seeds they had consumed elsewhere—perhaps from the few stands of mature native trees remaining on the island’s cliffs or even from the mainland.
It is a strange irony of conservation. We generally view feral pigeons and starlings as pests, yet in this highly modified landscape, they appear to be acting as the primary ecological engineers, bridging the gap that our absent native birds usually fill.
Thanks to our unexpected volunteers helping us replant the forest—one dropping at a time.
Following an amendment to Hauraki Gulf / Tīkipa Moana Marine Protection Bill last month I made an Official Information Act (OIA) request to Fisheries New Zealand (FNZ) asking for data on customary fishing inside the 12 proposed High Protection Areas (HPAs).
Customary fishing data (2022–present) – including authorisations, catch returns, or summaries.
Any reports or analyses (since 2022) assessing the potential biodiversity impacts of customary fishing inside HPAs.
The reason for this request was simple: without knowing how much customary fishing occurs in these areas, it is impossible to assess whether the HPAs will deliver the biodiversity outcomes the public has been told to expect. I asked for and received this data in 2022 but it was in poor shape.
They stated that under current regulations, authorised representatives are not required to report what they have approved or what has been caught under a customary authorisation.
Some representatives voluntarily provide authorisation records, but FNZ treats this information as confidential. The request was declined under section 9(2)(ba)(i) of the OIA, which allows withholding to protect information supplied in confidence.
FNZ confirmed that it has not produced any internal or external reports or analyses quantifying the biodiversity impacts of customary fishing in the HPAs. This part of the request was refused under section 18(e) – on the basis that no such documents exist.
In short: FNZ does not hold comprehensive customary catch data for the Gulf HPAs and has not assessed the biodiversity implications of customary fishing in these areas.
What has changed in the law
Originally, the Marine Protection Bill required biodiversity objectives for HPAs, and customary fishing had to align with them. That safeguard was contained in Clause 66 and Section 19.
But in July 2025, the Government amended the Bill. The amendment removed the link between biodiversity objectives and customary fishing. Customary non-commercial fishing in HPAs will now be regulated solely under the Fisheries Act 1996, with no requirement to align with biodiversity objectives (AP No 260).
This means biodiversity objectives will no longer manage customary fishing at all.
I think the changes create a serious gap in marine protection:
Unknown fishing pressure: We do not know how much customary fishing will take place in HPAs because reporting is not mandatory.
No biodiversity safeguard: There is no mechanism to ensure customary fishing aligns with biodiversity objectives for HPAs.
No impact analysis: FNZ has done no work to estimate the ecological effects of customary fishing within these areas.
Public confidence undermined: HPAs are promoted as “high protection,” yet the level of protection is uncertain and potentially weak.
The bottom line
The Gulf desperately needs effective marine protection. But protection must be real, not just symbolic. Right now, FNZ cannot say how many fish will be removed from HPAs, nor what impact that removal will have on biodiversity.
Worse, the recent amendments to the Bill mean biodiversity objectives—the very tool designed to ensure ecological recovery—no longer apply to customary fishing.
That is deeply disappointing. If HPAs are to succeed, they must be based on evidence, transparency, and enforceable biodiversity objectives. Anything less risks creating “protected” areas in name only.
Together with the allowance for commercial fishing in two of the HPAs, the reality falls far short of what the public expects from “high protection.” As MP Lan Pham put it in the House this week:
“My proposed amendment is to actually replace the definition of ‘High Protection Area’ with ‘Compromised Protected Area’.”
Commercial landings of kōkiri / leatherjacket in the Gulf have crashed by more than 80 percent in the past decade, yet Fisheries NZ says the population must be growing because new trawl gear lets more fish escape!
If you are not seeing more kōkiri then the catch decline is more likely indicating a population crash, and our friendly sea-squirt chompers are getting rarer while the catch limit stays sky-high. I’ve lodged a submission asking for a five-year closure of the LEA 1 fishery so these fish, and the reefs and mussel lines they keep clean, can recover.
Unless you’ve witnessed a sudden kōkiri boom yourself, please add your voice.
I was inspired by Professor Murray Cox (who had done some simulation work on exotic Caulerpa growth) to make a tool that predicts exotic Caulerpa coverage based on some currently unknown variables. Here is a link to my exotic Caulerpa simulator. Please feel free to email me if you have any new data which would make it more accurate.
Logging where and when I have been looking for the exotic Caulerpa species that have been recently introduced to Aoteroa New Zealand.
28 June, Low tide walking, 2hrs. This seagrass meadow near the Half Moon Bay Marina is vulnerable. Good coverage but a drone would be more effective. Checked the high tide line on my return.11 July, High tide scuba /snorkel 2hrs. This bay is north east of the Kawau Bay incursion. Dive report here.12 July, Low tide walking, 2hrs. This bay is north of the Kawau Bay incursion. Very calm and I could see a few meters under the water. Checked the high tide line on my return.25 July. High tide walking 2hrs. Beach cast seaweed on high tide line checked. 26 July. Low & Mid tide walking. Beach cast seaweed on high tide line checked. 26 July. High tide walking. Beach cast seaweed on high tide line checked. This marina is a vector.23 August, High tide scuba for 30 minutes around rock (swimming fast). Free dived at two other locations in the bay. This bay is north east of the Kawau Bay incursion
There have been decades of korero about marine protection in the Hauraki Gulf / Tīkapa Moana / Te Moananui-ā-Toi. Everyone knows we urgently need more protection but the Governments proposals are too small, experimental, slow and ignore Waiheke Island.
The only concern I have about the Hākaimangō – Matiatia Marine Reserve (Northwest Waiheke Island) application is the lack of published support from iwi authorities. My understanding is that the applicants and the Department of Conservation continue to engage iwi (nine months to date), but while iwi authorities at this stage have not committed their support they are interested in dialogue and importantly they have not opposed the application. Two leading descendants of 19th century Waiheke Ngāti Paoa chiefs, Moana Clarke and Denny Thompson have expressed open support. Iwi politics in the Treaty settlement era are complex and difficult for me as a pakeha to understand. I am concerned about the considerable expectations put on Māori. If we limit our support to co-designed or iwi led marine reserve applications we would be burdening iwi with a responsibility for marine heath they do not seem to be resourced to implement. There are no published concerns about the proposal from iwi. 77% of Māori support 30% marine protection in the Gulf (Hauraki Gulf Forum Poll 2021). I hope that the iwi leaders will put the mauri / lifeforce of the HGMP first and support the application. In the meantime the cautious approach of iwi authorities is no reason not to support the application. If any iwi do have concerns we should take great care to hear and work through those concerns, they have significant rights as mana moana.
UPDATE 28 February. A local iwi body the Ngāti Paoa Trust Board are supporting the application.
1. We don’t have enough protection. A tiny 0.33% of the Hauraki Gulf Marine Park (HGMP) is fully protected from fishing, the governments Revitalising the Gulf plan will hopefully increase this area to 0.575% by late 2024 (Revitalising the Gulf 2021). The other forms of protection suggested in the plan all involve some kind of fishing. We need places where with intact ecosystems where our taonga and heritage don’t get eaten. The proposed Hākaimangō – Matiatia Marine Reserve is a significant addition at 0.195% of the HGMP. All the proposed protections need to be actioned as soon as possible to reverse the decline of biodiversity and abundance in the HGMP (State of our Gulf 2020). If all the proposals are accepted only 6.7% of the HGMP will be protected from fishing (excluding cable zones which are not designed to protect biodiversity). We will need many more proposals to meet the Hauraki Gulf Forums goal of 30% protected.
2. It’s long term. Rāhui enacted through section 186 of the Fisheries Act only last for two years. This is not the right tool to use to sustain large breeding animals live for more than 50years. Tāmure / Snapper can live to at least 60 years of age (Parsons et. al. 2014).
3. It’s big. For decades scientists have been telling us that our marine reserves are not big enough to protect wildlife from the edge effect. If approved at 2,350 ha Hākaimangō – Matiatia would be the largest marine reserve in the HGMP.
4. It’s in a great spot. The site covers an ecological transition zone between the waters of the inner and outer Gulf. The inner Gulf is slightly cooler, more turbid, shallower, low energy (sheltered by a screen of islands including Waiheke Island) compared to the outer Gulf which is deeper, warmer, clearer and comparatively high energy marine environment. The site was select by marine biologist Dr Tim Haggitt after doing extensive surveys around Waiheke Island in 2015. The area is geologically remarkable for its extensive underwater platforms and terraces, the diversity in physical habitat is reflected in the flora and fauna.
5. There are plants and animals left worth protecting. Functionally extinct species like Kōura / Crayfish (Jasus edwardsii & Jasus verreauxi) are still found in the area so the recovery time here will be faster than other overfished areas of the HGMP.
6. We need more baby fish. It takes thirty six 30cm Tāmure / Snapper to make the same amount of eggs as one 70cm fish (Willis et. al., 2003). This marine reserve would dramatically increase egg production in the HGMP. Marine reserves make a disproportionate (2,330% Tāmure / Snapper in the reserve at Leigh) larvae spillover. Adult Tāmure / Snapper within the reserve at Leigh were estimated to contribute 10.6% of newly settled juveniles to the surrounding 400km2 area, with no decreasing trend up to 40km away (State of our Gulf 2020).
A 40km radius from the centre of the proposed marine reserve.
7. Fishing on the boundary will be awesome. The proposed marine reserve is big enough for people to fish the borders with a clear conscience. Fishing here will be popular with many big fish leaving the area (See Halpern et. al. 2009 on spillover).
8. People want marine reserves. Marine reserve support is strong and getting stronger. On island support for marine protected areas from island residents was 67% with off-island ratepayers at 54% in 2015. A 2021 poll by the Hauraki Gulf Forum shows general support for 30% protection at 77% with only 5% opposition. The poll showed no difference in support from Māori.
9. It’s a great cultural fit. Most people who live on Waiheke Island really care about the environment. Conservation values are strong across the different local communities.
10. It will be great for education. The marine reserve will create much richer outdoor education opportunities for the young and old people of Waiheke and Auckland. Rangitahi in particular will benefit from being able to experience an intact marine ecosystem. Te Matuku Marine Reserve is less suitable for education because the water clarity is dramatically impacted by sediment.
Left: Diver at high tide in the Te Matuku Marine Reserve. Right: Wheke / Sydeny Octopus at high tide in the proposed marine reserve. Photos by Shaun Lee.
11. Resilience to climate change. By maximising biodiversity and abundance the marine reserve will protect the HGMP from climate change impacts, particularly heatwaves, invasive species and ocean acidification. Marine reserves are like insurance against uncertainty.
12. Improving the economy via commercial fisheries. Juvenile Tāmure / Snapper leaving the Cape Rodney to Okakari Point (Goat Island/Leigh) Marine Reserve boosted the commercial fishery by $NZ 1.49 million per annum (Qu et. al. 2021). Auckland University found 10.6% of juvenile snapper found throughout the Gulf – up to 55 km away were sourced from this one marine reserve. The researchers found economic benefits to the recreational fishery are even more substantial. There are other commercially fished species in the area. The proposed marine reserve is four times bigger than the Goat Island reserve.
13. A benchmark. No harm marine reserves provide a reference point for assessing the impacts of our activities elsewhere. “As kaitiaki in the broadest sense, we have an obligation to preserve natural examples of marine ecosystems” – State of our Gulf 2020. Data obtained from marine reserve monitoring compliments fisheries information and matauranga Māori to help us understand environmental change.
14. Science. Marine reserves are a natural laboratory. They have contributed massively to our understanding of marine ecology and ecological processes. Many of our leading marine scientist studied and conducted research in marine reserves at Leigh, Tāwharanui, Hahei and elsewhere. Of course the Marine Reserves Act expressly recognises the scientific importance of marine reserves. Scientific research is an over-riding priority in the Act,
15. Tourism benefits. The marine reserve will add to the growing ecotourism opportunities on Waiheke Island. It complements the $10.9 million dollar investment in Predator Free Waiheke (Predator Free 2050 Limited 2021) which has a vision to become the world’s largest predator-free urban island. The marine reserve will be much cheaper to create and maintain and will deliver a mountains to the sea nature experience.
16. Return on investment. The Cape Rodney to Okakari Point Marine Reserve (Goat Island) generated $18.6 million for the local economy in 2008 at a cost of about $70,000 for the Department of Conservation (State of our Gulf 2020).
The Hauraki Gulf / Tīkapa Moana / Te Moananui-ā-Toi can not afford to have this application sit on a shelf waiting for stronger political leaders. Please start the process of creating the Hākaimangō – Matiatia Marine Reserve and healing the wider area as soon as possible.
Parsons DM, Sim-Smith CJ, Cryer M, Francis MP, Hartill B, Jones EG, Port A Le, Lowe M, McKenzie J, Morrison M, Paul LJ, Radford C, Ross PM, Spong KT, Trnski T, Usmar N, Walsh C & Zeldis J. (2014). Snapper (Chrysophrys auratus): a review of life history and key vulnerabilities in New Zealand, New Zealand Journal of Marine and Freshwater Research, 48:2, 256-283, https://doi.org/10.1080/00288330.2014.892013
Qu et. al. (2021). Zoe Qu, Simon Thrush, Darren Parsons, Nicolas Lewis. Economic valuation of the snapper recruitment effect from a well-established temperate no-take marine reserve on adjacent fisheries. Marine Policy. Volume 134. https://doi.org/10.1016/j.marpol.2021.104792
Willis, T.J., Millar, R.B. and Babcock, R.C. (2003), Protection of exploited fish in temperate regions: high density and biomass of snapper Pagrus auratus (Sparidae) in northern New Zealand marine reserves. Journal of Applied Ecology, 40: 214-227. https://doi.org/10.1046/j.1365-2664.2003.00775.x
Halpern, B., Lester, S., & Kellner, J. (2009). Spillover from marine reserves and the replenishment of fished stocks. Environmental Conservation, 36(4), 268-276. https://doi.org/10.1017/S0376892910000032
How to identify Australian Winged Wētā / (Pterapotrechus sp) which have been introduced to New Zealand.
Update February 2025: Orthopterist Danilo Hegg has identified the Australian Raspy Cricket to a species level, it’s called Pterapotrechus salomonoidesso
