The unmanaged fisheries of the Hauraki Gulf Marine Park

In New Zealand, we have 75 fish populations that are supposed to be managed sustainably. The main way we do this is by setting limits on how many fish can be caught, known as the Total Allowable Catch (TAC). We don’t keep regular track of the fish caught by recreational and cultural fishers. The only annual numbers are for commercial fishing, which has a limit called the Total Allowable Commercial Catch (TACC).

What’s puzzling is that for many fish populations, the TACC is set way higher than what’s actually being caught, and it’s been like that for years without any change. To me, this means these fish aren’t really being managed at all. Of the 75 in Aotearoa there are 16 fish populations in the Gulf that stand out as ‘unmanaged’ due to their TACC being significantly higher than the actual catches.

I had high hopes for the new Fisheries Management Plan for the Gulf, thinking it might sort out these unmanaged populations. I tried to get some answers by writing to the minister, and when that didn’t work, I filed an Official Information Act request. The reply came from Simon Lawrence at Fisheries New Zealand, but it wasn’t what I hoped for. They’re only planning to review four out of the 16 unmanaged populations this year – Flatfish, Rig, Blue cod, and Red cod. That leaves Pipi, Horse mussel, Paddle crab, Anchovy, Sprat, Pilchard, Jack mackerel, Pōrae, Leatherjacket, Trumpeter, Longfin eel and Spiny dogfish unmanaged. Four of these fish are at the bottom of the food web and are critical for the Gulf ecosystem function. Horse mussels are endemic (found only in New Zealand) and aggregations dense enough to be called beds are now extinct in the Gulf, Longfin eel are also endemic and going extinct.

So here we are, with a fisheries plan that talks a big game about moving towards an ‘ecosystem-based fisheries management‘ approach, but we’re not even effectively managing individual fish populations.

Anchovy Engraulis australis kokowhaawhaa
 Jack mackerel Trachurus declivis Trachurus novaezelandia Trachurus murphyi Haature
New Zealand pilchard Sardinops sagax Mohimohi
New Zealand sprat Sprattus muelleri Kupae
Smooth leatherjacket velvet leatherjacket Meuschenia scaber Kokiri
Trumpeter Latris lineata Kohikohi
Porae Nemadactylus douglasii Morwong
Spiny dogfish Squalus acanthias snow fillets Makohuarau Pioke
Longfin eel Anguilla dieffenbachii Tuna
paddle crab  Ovalipes catharus Pāpaka
horse mussel Atrina zelandica Hururoa
pipi  Paphies australis

LegaSea’s displacement argument

LegaSea are asking their supporters to object to the Hauraki Gulf Marine Protection Bill due to concern’s about displacement.

“We do not believe the proposed protection measures go far enough to restore fish abundance and biodiversity in the Hauraki Gulf. Marine protection and fisheries management controls need to go hand-in-hand, otherwise all we will do is shift current fishing effort into our neighbour’s waters. We want 100% of the Hauraki Gulf seafloor protected from destructive, mobile fishing methods including bottom trawling, Danish seining and dredging. And, we want Ahu Moana, a joint iwi/hapū and community driven solution to resolve local depletion issues.” (Full email published here).

If we forget about the many non-fishing benefits of marine protection, then also forget about the fisheries benefits of marine protection (nursery and spillover) then forget about the fisheries plan which aims to rebuild stocks including Ahua Moana we are left with LegSea’s naïve argument over a limited amount of fish. Does it stand up?

No, the recreational losses for all species fished in the HPAs total 293 tonnes, the proposed commercial reductions from the corridors will total between 632-1017 tonnes.

Update January 2024. Marine scientists at the University of Auckland have done some excellent work looking at the displacement argument.

Math + references:

Calculating the weight of recreational catch lost to HPAs

Recreational fishers harvested 2,068 tonnes of snapper from the HGMP in 2017/18 fishing year. 9.58% of the recreational fishing effort is in the proposed High Protection Areas. The HPAs will reduce recreational fisheries catch of snapper by 198 tonnes. 

Recreational fishers harvested 517 tonnes of kahawai from the HGMP in 2017/18 fishing year. 9.58% of the recreational fishing effort is in the proposed High Protection Areas. The HPAs will reduce recreational fisheries catch of kahawai by 50 tonnes. 


These two species represent 82% of the fish (by weight) caught in the Gulf in the 2017/18 fishing year. 


Recreational catch in the HPAs for the 2017/18 fishing year = 248 + 18% (45) = 293 tonnes. 

Calculating the weight of commercial catch lost to trawl corridors

Option 1 would result in an estimated reduction in landings of approximately 632 tonnes of fish per year. Option 4 would result in an estimated reduction in landings of approximately 1017 tonnes of fish per year.


Untangling the conservation and ethical dilemmas of big game fishing

Marlin hooked, fish feel pain

This summer many people asked me about a front page article on the New Zealand Herald about a large black marlin that was killed off the coast of Northland. They wanted to know what I thought about it because they knew I would disapprove. The article did not include other views on the anglers “monumental effort” which took 10 hours. People posted negative reactions to the article on Facebook calling it animal torture but there was a shortage of facts about conservation and moral concerns.

Is marlin fishing sustainable?

In Aotearoa New Zealand the fishery of marlin is 100% recreational since 1988. Billfish caught overseas should not be bought to eat because bycatch from this fishery is going extinct (whales & dolphins, sharks, seabirds and turtles). Our commercial catch of billfish is not targeted due to a Memorandum of Understanding Between Commercial & Recreational Fishing Interests October 1996. However there is a targeted commercial Swordfish fishery. Commercial landings have fallen dramatically over the last 10 years indicating a change in fish population, fishing methods or reporting, the former is most likely and concerning *. The 126 tonnes of landed in the most recent year represents more than 1,000 fish, more than the number of animals reported in the recreational tag and release programme. Other billfish like marlin are released whether the animal is alive or dead upon capture. Cameras on all commercial surface longline fishing boats would tell us how many of these animals are being released (alive or dead).

Commercial landings of swordfish in the Aotearoa / New Zealand EEZ

The population trend and conservation status of each species is assessed by the International Union for the Conservation of Nature (IUCN). This is how they categorise the threat of extinction for all species on our planet.

How the International Union for the Conservation of Nature (IUCN)categorise the threat of extinction for all species on our planet

Here is how our billfish populations are doing in 2023 with recent catch data from the tagging program.

Black marlin population trend
Striped marlin population trend
Swordfish population trend
Blue marlin population trend
Shortbill spearfish population trend
Note that catch from the 2019-2020 was impacted by the Covid 19 pandemic so I have used the previous years which is more indicative of average catch.

Most of the recreationally caught animals are striped marlin, although they are categorised as Least Concern, the population in the Southwest Pacific is overfished with an estimated decline of 25% between 2001 to 2016.

Aotearoa New Zealand participates in the Western and Central Pacific Fisheries Commission to manage broadbill populations. This 26 member commission is slowly making progress towards sustaining the world’s biggest tuna fishery, but failing to manage bycatch including billfish. The commission meets just once a year to make decisions via consensus. Aotearoa New Zealand is responsible for a very small percentage of the fishery. We have the moral high ground and are well positioned to argue for changes to stop these species from going extinct.

While commercial billfish bycatch in Aotearoa New Zealand is unknown, recreational fishers both target and land billfish. Because our fisheries are recreational, reporting on how many billfish are caught is voluntary. The latest report on the tagging programme notes an increase in the number of boats and a probable increase in unreported catch. This needs to change and more information would help us with our questions about the conservation status of these species. Climate change will push billfish populations towards the poles, increasing catches in Aotearoa New Zealand and masking our ability to detect population decline here.

The sports fishing industry awards and celebrates the capture of the largest fish. Large old fish produce more eggs and sperm than younger fish. Female billfish are larger than males. This means the most productive members of the population are landed for records, trophies and prizes. A large blue marlin at a weigh-in station does not represent a gain of 500kgs of freezer meat, but a loss of millions of eggs which could have helped rebuild the population. The situation is just as important for our striped marlin which have lost 94% of their spawning biomass since 1960’s.

Marlin batch spawn in tropical waters.
Marlin batch spawn in tropical waters.

As our culture evolves fishing is becoming less about machismo and more about connecting with the environment. Recreational fishing industry leaders could do more to discourage fishing techniques that target species that are going extinct. They also need to find ways to land less big fish. It won’t be easy for them, change may take a generation. Is catch and release the solution?

Is catch and release helping conserve billfish in Aotearoa New Zealand?

About 800 of our billfish are caught, tagged and released every year. The tagging programme is voluntary for recreational and commercial fishers. On average only three of these are recaptured per year. The other 797 plastic tags (which cost $5 each) end up in the ocean. Some tags fall out, some sink to the bottom of the ocean with the exhausted fish.

Many billfish are released, all of them injured. The fish are vulnerable to shock, disease and predation.

Marlin released with or without tags are vulnerable to shock, disease and predation.
Marlin released with or without tags are vulnerable to shock, disease and predation.

Overseas studies have found survival is not great with one in seven released fish dying. Fishers gamble with the lives of these animals every time they put a hook in the water. The ‘catch and release’ practice makes a significant contribution to the sustainability of our share of the fishery – if its stopping those fish from being landed and killed. However it’s unquestionable that the fish would be better off without being caught at all.

The small number of recaptures have shown where our fish travel, but much more information could be gained by using satellite tags. Genetic sampling techniques are better conservation tools and have existed for more than five years.

With so little conservation value in the tagging programme, is it worth it?

Is catch and release humane?

Sportfishing is practiced by humans who primarily hunt for fun rather than food. It’s a blood sport where wild animals are stressed and wounded for the pleasure of the hunter. In 2003 scientists found that fish have the biology to perceive pain and demonstrate behaviours associated with pain. The science was controversial for more than a decade, but now seems settled and researchers have now moved on to what kind of painkillers to give fish in laboratory experiments.

Marlin hooked, fish feel pain
Marlin feel pain.

Billfish respond to a hook in the mouth, throat or guts by trying to move away from the source of the pain. Fishers call this the ‘fight’. The amount of fight a fish will put up to reduce its suffering is extended by international game fishing rules. These rules are endorsed with additions from Legasea / The New Zealand Sports Fishing Council. They encourage fishers to try and land game fish on lighter line classes. This is thought to give fish a “sporting chance” as heavier fish can more easily break lighter lines. This makes the fights (which the fisher instigates for their own enjoyment) longer, it’s not uncommon for fights to last hours. This is done at the expense of the fish. Longer fights prolong the suffering of billfish and increase the chances of post release mortality due to physiological stress.

The New Zealand Society for the Prevention of Cruelty to Animals (SPCA) opposes big game fishing for sport due to the prolonged pain, injury and distress on the fish involved. SPCA advocates for a ban on the use of “light tackle” to catch big game fish.

The New Zealand Animal Welfare Act 1999 recognises fish as sentient animals. The activity recklessly ill-treats animals (an offence under section 28 A) it also contravenes other sections of the act (30A1-3). There is a NAWAC guideline on how to deal with practices which are inconsistent with the spirit of the Animal Welfare Act. The guideline asks ‘Is the suffering necessary’? It is not necessary and undeniably inhumane.

There is enough conservation and moral evidence to take the precautionary approach and stop the sport today, but I think it should be phased out, like big game hunting overseas.

Big game fishing is being compared to (less socially unacceptable) big game hunting

What should we do?

Aotearoa New Zealand should show leadership by pushing for global population estimates using genetic tools. We need to do a better job of arguing for changes to international fisheries methods and quota. We can also show more leadership by mandating the reporting of caught billfish (both landed and released, commercial and recreational) and developing a Code of Welfare for sports fishing which will identify standards to prevent pain and distress.

* UPDATED APRIL 2024. Phil Clow (president of the Whitianga and Coromandel Peninsula Commercial Fisherman’s Association) pointed out that the drop in commercial swordfish catch is due to fishers targeting tuna instead. I looked into it and it does look like that accounts for 50% of the drop. Annotated graph below.

The enchanted gardens of North Eastern New Zealand

Photo Auckland Libraries Heritage Collections NZG-19071116-0009-03

I was horrified by this photo I found in the Auckland Libraries Heritage Collection. It was taken 116 years ago in 1907. The caption reads ‘beautiful but profitless’ and describes a haul of corals and sponges undertaken by a research trawler. One large Black coral is remarkably intact, a tragic loss. The caption describes the scene “A haul as this—which in trawling parlance is “muck”—though useless is a glorious sight. This one in particular was gorgeous. The fish were a brilliant rose-pink, and all the hues of the rainbow were to be found in the strange dwarf trees, and other growths which came up in the net.”

The photo was from an article published in New Zealand Graphic which can be found in Papers Past, a second part to the article was published the following week.

The story is written about a single trip which started in Auckland on the 17th of October, the end is not mentioned in the article but based on the fisheries scientist’s report (from 1907 on PapersPast, there is also a 1901 report in the same National Library archive ) they went to the North Cape and back, making 23 trawls in 11 to 55 fathoms (20-100 meters). There are notes on all 23 trawls, the photo is likely from one of these:

Station 177: The net was shot again at 9.55 a.m., 6 miles N.W. £ W. of Channel Island, depth 25 fathoms, bottom mud and sand. As soundings indicated rough bottom, the net was only towed an hour and hauled up in 27 fathoms, bottom coral and shell. The result of this haul, poor both as regards the quantity and variety of fish.

Station 178: From last station steamed 5 miles S. x E., and shot the net at 12noon, 4miles S.S.E. from Little Barrier, depth 28 fathoms, bottom mud and sand. Hauled up 4J miles W. \S. of the Little Barrier in 28 fathoms, bottom coral and shell. This was also a short haul, and the results were as poor as the previous one.

Station 183: Left Russell at 6 a.m. for Great Exhibition Bay, near the North Cape. Arrived there and shot the net at 3 p.m. in 32 fathoms, the soundings made showing sand and shell; but the net had only been towed ten minutes when it fouled, and. when hauled up it was found that the foot-rope was cut through, showing plainly that it had come in contact with rocky bottom.

Station 191: After hauling up from station 190 several soundings were taken, and showed a risky bottom, so we steamed south 17 miles, and shot the net at 4.30 p.m. off Takau Bay in 35 fathoms, bottom fine sand. Towed S.E. 2 miles, and hauled up from the same depth and character of bottom as we shot in. This was a very poor haul as regards fish-taking : the net came up with large quantities of marine vegetation. After hauling up we steamed into Russell, and anchored for the night.

They lost a £lOO net on “foul ground” and they were constantly mending nets. The author describes the seafloor based on the bycatch “places must be like a fairy grove, or one of those enchanted gardens in the Arabian Nights”. He goes on to describe a particular haul from the Bay of Islands in detail:

“There were several dwarf trees about three or four feet high, which realised one’s idea of the sort of thing that grew in the garden of the Princess Bulbul. They had evidently been torn from the solid rock. The branches were covered with feathery leaves of a most delicate form, coloured cream-brown, and attached to them were all manner of things just like a Christmas-tree. From a short distance off, it was difficult to say that it was not hung with all manner of vivid-hued fruits—bananas, grapes, tomatoes, and what not—anu round the branches at intervals were twined starfish in knots resembling what sailors call “Turk’s Heads.” They were not spiked like ordinary star-fish, but smooth and bright as a Japanese lacquered box. Some were cream with maroon stripes, others a rich golden yellow, others crimson, and on no two was the marking the same. From one branch depended a cluster of things half prawn, half sea-horse, and from different points swung shark’s eggs—a semi-transparent lyre-shaped bag of the same colour and quality as celluloid (from which it was difficult to distinguish it), some four inches in attached to the shrub by cartilaginous tendrils, whose spirals seemed intended by wonderful Mother Nature to catch in such growths and find a safe hatching place. One branch minus leaves, if one could so term the feathery growth, looked exactly like a frond of coral, the colour a rich crimson-lake, with the tips of the countless excrescences lighter in tint. On a closer examination the branch was found to be sheathed with a gelatinous substance, quite soft to the touch, which soon dried and lost its exquisite colour.

Some of the shells were very strange and interesting, particularly one that seemed to be very plentiful. It was an ordinary-looking spiral shell as big as a man’s hand, but round the base was ranged a number of smaller shells, forming a sort of base which would apparently keep the shell off the ground, like a house on piles. They were stuck on with some kind of cement, and in other specimens small stones or pebbles were used in a similar way.

Sponges, and fungoid growths of many colours and fantastic shapes—umbrellas, hats, bowls, etc.—were common, and some of them weighed half a hundredweight and more. Star fish, squids, molluscae, medusae, seaweed and yards of gelatinous transparent stuff as thick as leather and marked with red spots were brought up at nearly every haul. They would no doubt be greatly prised by the naturalist, but are shovelled over without the slightest compunction by the business-like fisherman.”

By 1907 there were many trawlers operating around the country, many purchased with government subsidies. There had been much public outcry about the method and one area in the Gulf protected (temporarily) but only after it had been trawled. In 2023 commercial bottom trawlers and Danish seiners will repeatedly deploy their gear thousands of times within the Hauraki Gulf Marine Park alone.

The image is a stark reminder of what’s been directly lost to mobile bottom impact fishing. The industry like to say they only trawl on ‘sand or mud’ but we know that our mud and sand once supported more complex habitats. Examples of biogenic habitats that associate with soft sediments include horse mussel beds, scallop beds, dog cockle beds, green-lipped mussel beds, seagrass, sponge gardens, tubeworm mounds and rhodolith beds. Our poorly protected corals and other epibenthic fauna like sea squirts attach to hard structures created by these habitats, enriching and expanding these ‘enchanted gardens’. All of these habitats are easily destroyed by mobile bottom impact fishing.

To this day NIWA carry on this tradition of ‘scientific’ bottom trawling for the government, even in areas protected from bottom trawling. Some tows are stoped due to ‘foul ground’. When will we stop all mobile bottom impact fishing and begin to restore our ‘enchanted gardens’?

My experience in designing ‘trawl corridors’

Unlike the Sea Change 2017 marine spatial plan that sought to phase out bottom impact fishing from the Hauraki Gulf Marine Park the governments response (Revitalising the Gulf 2021) was to create ‘trawl corridors’. Bottom trawlers do not have a public license to keep smashing the seafloor, a 2021 Horizon Research poll had 84% support for a banning the practice. I love the seafloor and volunteer for an organisation that restores damage done to it by bottom impact fishing. I’m completely opposed to trawling as a fishing method but I put my hand up to help limit its impact in the Gulf using a science based process by joining the Hauraki Gulf – Benthic Spatial Planning Advisory Group (HG-BSPAG).

This was my first experience in a collaborative decision making process run by the Government with industry representatives. I represented an environmental Non-Government Organisation (eNGO), there were three eNGO participants, everyone else was either from NIWA, central & local govt or the fishing industry. The process was chaired and controlled by Fisheries NZ. The other two eNGO participants were awesome and I learnt a lot from them.

I particularly liked the data first approach to marine spatial planning, Zonation is a great tool and I liked the way it starts by removing the human impacts then making an economic case for re-introducing them. Unfortunately some data that would have been useful was not quite complete.

Fisheries NZ controlled the outputs by defining what is in scope. Here is a list of requests that were disregarded:

  1. Ground truthing the modelling work (out of scope).
  2. Modelling the distribution of Unwanted Organisms (UOs) . We know from NIWA surveys that trawl nets catch UOs in the HGMP, transporting UOs is an offence under Section 52 of the Biosecurity Act 1993. By excluding UO’s from the study FNZ failed to protect native benthic habitats from UO’s which can be spread by bottom impact fishing (see appendix for more details).
  3. Infauna (animals that live in the sediments) that are sensitive to bottom impact fishing were excluded from the modelling due to technicalities.
  4. Mobile species that contribute biogenic habitat like tipa / scallops (see appendix) and burrowing animals like ghost shrimp and crabs were excluded because they were mobile which did not suit their definition of biogenic habitat. This is ridiculous as the smallest grid size is 250m and previously mentioned adult animals are unlikely to move more than 10m.
  5. Important habitats for fish (like spawning and nursery areas) were not considered (out of scope).
  6. The indirect effects of bottom impact fishing. Sediment plumes from bottom impact fishing choke and kill filter feeding animals and smother photosynthesising plants. These effects were not included but have been discussed at the end of the report.
  7. Climate change impacts (e.g. CO2 released from resuspending sediments and heart urchins moving deeper as water warms) also not included but have been discussed at the end of the report.
  8. Modelling the economic benefits of excluding bottom impact fishing to other fisheries that don’t impact the seafloor, this could have dramatically altered the findings (out of scope).
  9. Monitoring changes in the money made in an area over time during the transition from one fishing method to another, I think it’s critical this is done with any changes to bottom impact fishing.
  10. Using the regulations, not existing fishing effort, as the starting point for limiting Danish seining (see appendix on Danish seining regulations). Despite multiple requests FNZ would not even put the existing regulations on the maps.
  11. Protecting the deeper areas of the HGMP (see appendix).

We did not discuss substrate. Is it better to trawl on sand which emits a smaller plume but may transition to mud with intensified disturbance, or mud which has a larger sediment plume? We know repeated bottom impact fishing alters the chemistry of the seafloor.

The narrow scope of the project was frustrating because there is an aspiration for Ecosystem Based Management of the Hauraki Gulf Marine Park. Once all the environmental effects of bottom trawling and Danish seining are considered, the fishing methods should be banned everywhere.

I have some sympathy for fisheries managers, they have specific deliverables and get pushed around by industry. I did think their approach was often callous, in the face of uncertainty they often chose the status quo rather than taking a more precautionary approach. One member of the Hauraki Gulf Fisheries Management Plan Working Group HG-FMPWG that will finish the corridor design work has publicly criticised the process.

There were no opportunities for feedback on the corridors the scenarios produced. Final trawl corridor design will be Fisheries NZ’s responsibility and will get input from the HG-FMPWG. Other than the above I have no criticisms of the process, it just needs bigger budgets and managers who care more about te taio. I learnt a lot and am happy to volunteer my time again to use scientific modelling in a spatial planning process to protect the environment.

One difficulty I had was proposing trawl corridors. I decided not to volunteer a low impact scenario because the process had already generated a near zero impact scenario which I thought was reasonable (Similar to Figure 14C in the published report – 90% of recovery potential habitat and current trawl footprint & current/proposed protected areas and 100% of current distribution of biogenic habitat (minimising impacts on trawl fishery.) This meant I was left very unhappy with the scale of the proposed scenarios. It was obvious that the scenarios would need work before Fisheries NZ could designate corridors, however I may end up regretting that decision.

I hope Fisheries NZ will monitor recovery (which may take centuries) the data gained could help ground truth this model and develop more robust models in future.

You can read the published report on the design process here: Exploring the use of spatial decision support tools to identify trawl corridors in the Hauraki Gulf Marine Park

Advice for the Hauraki Gulf Fisheries Management Plan Working Group

The outputs of the process will be used by the Hauraki Gulf Fisheries Management Plan Working Group to design bottom trawling corridors in the marine park. Here are some key points they should be aware of:

  • Because the process is not ground truthed and does not account for secondary impacts, important habitats for fish or climate change impacts a precautionary approach should be taken. (I suggested massive buffers but they were deemed out of scope).
  • Danish seining impacts have not been included in the model. This skews the impacts, recovery in areas where this fishing method is practiced has been understated.
  • The corridors should be much deeper (further from the coast) to avoid the illegal transport of Unwanted Organisms.
  • Consider the existing Danish regulations as the starting point, not the area where the fishing method is currently practiced.
  • Protect the deeper areas of the Gulf because they are included in the Hauraki Gulf Marine Park (see appendix).
  • Include monitoring (fisheries method transition) in any recommendations.
  • Take special note of the sediment resuspension impacts detailed on page 68 of the report which were excluded from the study.


Avoiding tipa / scallop beds

Running heavy trawl gear over tipa / scallop beds is incredibly damaging and foolish behaviour. It not only damages the tipa including juveniles, but also the settlement substrates the tipa use as part of their lifecycle. The Review of Sustainability Measures for New Zealand scallops (SCA 1 & SCA CS) for 2022/23. 3.1.18 states that:

“Within the Hauraki Gulf Marine Park, overlap between trawl activity and scallop beds will be considered as part of the proposal to establish defined ‘trawl corridors’ that will limit the areas where bottom trawling can continue to operate. With the introduction of electronic reporting and Global Position Reporting (GPR) on commercial fishing vessels, Fisheries New Zealand has the ability, through fine scale data, to monitor any notable overlap between fisheries and methods.”

It was frustrating that even though tipa are the most surveyed biogenic habitat in the Gulf the fisheries scientists decided that instead of identifying them they would just model their associated habitats. In the paper they literally say they ‘hope’ that this would mean the beds would be avoided rather than just mapping them out. Only the small beds that remained open at the time of the study (the fishery has since collapsed with bottom impact fishing implicated as a key stressor) were removed from the study area.

The rationale for the exclusion of tipa was that they are very mobile. This is ridiculous given the grid size of the study is 250m. Adult tipa and burrowing animals are unlikely to move more than 10m in their lifetime. For adult tipa mobility see Morrison, M. A. (1999). Population dynamics of the scallop Pecten novaezelandiae in the Hauraki Gulf (Doctoral dissertation, ResearchSpace@ Auckland).

Danish seining regulations

The restrictions prescribed in fisheries regulations for Danish seining define a different area than what is currently applied by Fisheries NZ. The State of our Gulf 2020 quotes Fisheries  NZ as ‘committed to reviewing this discrepancy as part of management actions put forward in a fisheries plan for the Hauraki Gulf’. The discrepancy is not recorded in the final report.

Protecting the deeper areas of the HGMP

The deeper areas of the HGMP were excluded from the final scenarios. I asked that they be protected because:

  1. The edges of continental shelves are biodiversity hots spots. Predicted diversity along the depth incline is one of the reasons for excluding the area from the model.
  2. This process was designed to protect biodiversity.
  3. This is the only deep water area in a marine park in New Zealand.

Unwanted organisms discussion document

Here is the discussion document on an unwanted organism (Mediteranean fanworm) I prepared for the working group, similar logic could have been applied to other species including the two recently introduced Caulerpa species.


The report details protection measures proposed by Sea Change 2017 but omits the most important benthic protection measure, “the phase out of all bottom trawling, Danish seining and scallop dredging from the Hauraki Gulf, with all such methods excluded by 2025” It’s a strange omission that reads like an attempt to exclude the measure from the history books.

Dredged to death

Fridays closure of the last two tipa / scallop beds in Aotearoa / New zealand will mark an historic moment for our fisheries. It signals the collapse of more than a fishery but an entire ecosystem. 

The last commercial mussel was dredged out of the Hauraki Gulf in 1966, after 56 years there are no signs of recovery. We don’t yet know what the fate will be for tipa. The fishery at the top of the South Island has been closed since 2017. If the tipa beds do not recover it will be the best evidence of ecocide in Aotearoa / New Zealand this century.

We need to change our ways. Both recreational and commercial dredging must be banned as per the Hauraki Gulf 2017 marine spatial plan that the government has still not acted on. These fishing methods damage the habitat that the animals grow in.

The result is:

  • Dead and damaged non target species and juvenile tipa
  • Lost biodiversity and water clearing animals
  • Lost habitats for fish especially juvenile fish
  • Long term changes to seafloor chemistry

The same impacts are created by other bottom impact fishing methods like bottom trawling and Danish seining which were also to be banned in the marine spatial plan. Short term fisheries closures are not good enough, we need a total ban on these methods.

Central government management actions to date have been irresponsible. Auckland Council did not take action when it was asked.

If the tipa beds do not recover naturally who will pay to restore them?

How to manage dogs in banned areas

Note this was written from the perspective on an average sized white male in his 40’s, you may need different tactics. The number one rule here is to never put yourself in danger.

Scenario 1. The dog is off-lead and there are threatened breeding birds in the area.

Chase after the dog. This shows the owners that something is really wrong, especially if you don’t look like the kind of person who likes to run. In my experience the dog usually returns to the owner, you can then have an (out of breath) conversation about why it’s important not to have dogs in the area.

Scenario 2. The dog is on a lead, there are no threatened breeding birds in the area.

Introduce yourself to the dog owners like you are an old friend. Be warm and in their face. This shows you are not somebody to be ignored but also not threatening. I like to shake their hand and tell them what I do here, my name, I also ask for theirs. Kindy explain to them that they must have missed the no dogs sign and send them back the way they came. It’s a good idea to walk with them as this shows how serious you are. Asking them about their dog(s) helps you come across as relatable, it’s also useful to find out if they are a local.

Scenario 3. Dealing with repeat offenders.

I have actually never had this problem but I received this advice from Auckland Council after having an argument with a local who was determined he was allowed to walk his dog somewhere where he was not.

1. Record the offenders details.

  • Ideally you already have their name from Scenario 2, if not ask for it again in a friendly way and apologies for forgetting.
  • Get a description of the dog (its breed, colour, sex, size etc and a description of the collar).
  • If the dog is not with its owner and it is safe to do so you might be able to get its tag details, for this you want the tag number and expiry date.
  • You might be able to get a photo of the owner or dog.
  • You might also be able to follow them to their car or house to record a license plate or address – but never put yourself in danger.

2. Report the details to Auckland Council (09) 301 0101 with the time, date and location. You will also need to report your contact details.

If Council officers are able to locate the owner an infringement may be issued. Keep a record of the incident for yourself. If there are regular incidents you can ask Council to do monitoring. In this case someone from the animal management team will visit the reserve. My understanding is that they can issue infringement notices on the spot.

Unprofessional editorial

An open letter to Keith Ingram.

In your July / August 2022 issue of Professional Skipper you ran an editorial titled How important are marine reserves?. You made a bunch of incorrect statements that I thought someone else would correct but I’m told the latest issue does not include any retractions. I have corrected them here:

“Recent statements by prominent yachties Peter Burling and Blair Tuke on Behalf of Living Ocean calling for 30 percent of the Hauraki Gulf to be under marine protection by 2030 are totally ill-founded”

The organisation is called Live Ocean not Living Ocean.

The statement is well founded by the 30×30 goal and the Hauraki Gulf Forums 30% goal which would leave 70% of the Gulf for fishing.

You go on to criticise the marine reserve proposed for Northwest Waiheke without pointing out a single problem with the application. You also ask what this group has in mind. Here is the application.

You claim there was “secrecy” but according to this statement from the Friends of the Gulf the application process was in plain sight and far from secret.

[After submitting the draft application for the Hākaimangō – Matiatia Marine Reserve to the Director-General of DOC and simultaneously to the two Ngāti Paoa Trust Boards a month was allowed for their unlobbied consideration. FOHG then went public with presentations to the Waiheke Local Board, The Local Piritahi Marae, Hauraki Gulf Forum, neighbouring property owners, other community organisations both on and off-island and articles, letters and advertisements in the Waiheke local newspapers The Gulf News and The Weekender and widely published on social media, national news media and radio. Following 10 months of pre-notification consultation, the revised application was lodged, advertised in all the main centre daily newspapers and distributed with two months allowed for public submissions or objections. This drew 1,303 public submissions. 1,183 were in full support.]

“Charterboat catch data is hugely valuable in showing how productive the gulf is at the moment and what it was like over the past 20 years, which I suggest is very different to the negative assessments of the state of the Hauraki Gulf that the environmentalists typically publish”

It’s not logical to decide the state of an ecosystem the size of the Hauraki Gulf Marine park using a single source of data like ‘charterboat catch’. The state of the environment reports are required every three years under the Hauraki Gulf Marine Park Act. They cover a broad range of indicators and massive data sets.

“Some recent nasty marine invaders that have adapted to our waters include the Asian paddle crab, the Chinese mitten crab, Stela clava. the Mediterranean tube worm. the Asian nesting clam, Caulerpa taxifolia and Undaria (Japanese kelp).”

There are no Chinese mitten crabs or Asian clams in Aotearoa / New Zealand, if you do find either of these species please phone Biosecurity NZ (0800 80 99 66) immediately.

You say: “Locking up marine areas won’t solve these problems” Marine reserves are more resilient to climate change impacts including invasive species because there are no gaps in the ecosystem created by overfishing. They can also help overfished areas recover after a pollution or climate event because they have more old animals that make a disproportionate contribution to recruitment. Here are some graphics I produced to explain the concepts.

Marine heatwaves are creating local extinctions The role of MPA's in climate change
It takes thirty six 30cm snapper to make the same amount of eggs as one 70cm snapper.

Let me know if you need more examples.

“Marine Protected Areas are not a fisheries management tool.”

I agree MPAs are a conservation tool, but MPA’s can also have fisheries benefits. For example this research from the University of Auckland and NIWA estimates that spawn originating in the small Marine Reserve at Leigh contributed “commercial fishery of $NZ 1.49 million catch landing value per annum and $NZ 3.21 million added from recreational fishing activity associated spending per annum” (Qu et al. 2021). The short term loses are offset by future gains. It will be interesting to see if Fisheries New Zealand take a long term view of the proposal in their impact assessment. I suggest you read this great article by Good Fishing which looks at the proposed High Protection Areas.

“The marine reserve legislation administered by DoC prohibits … the movement of vessels carrying flora and fauna through MPAs or reserves.”

This is inncorrect.

“An amendment to the Fisheries Act could provide for… the same result as Marine Reserves”

Unfortunately this won’t help as the agency has been captured by industry. One new tool we can use is the RMA which gives areas a break from fishing 10 years at a time. It’s disappointing that Legasea have not embraced the tool, which can stop bottom impact fishing once it is in discrete areas (for example ‘corridors’).

“We need honest, sound and reasonable leadership in this debate”

Agreed, if you want help fact checking any future editorials about marine biodiversity I would be happy to help.