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. 

– https://www.doc.govt.nz/globalassets/documents/getting-involved/consultations/2022/revitalising-the-gulf-2223/stage2-revit-gulf-economic-impact-assessment.pdf

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

– https://gulfjournal.org.nz/wp-content/uploads/2020/02/State-of-our-Gulf-2020.pdf

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.

– https://www.mpi.govt.nz/dmsdocument/58729-Discussion-document-Bottom-Fishing-Access-Zones-in-the-Hauraki-Gulf-Marine-Park

Submissions on the protections proposed by Revitalising the Gulf

I spent a few days going through the 7,550 submissions on protections proposed by Revitalising the Gulf. I’m estimating 77%-90% of the submissions were positive about the protection proposals. However huge numbers concerned about the continuation of bottom impact fishing outside the protected areas and cultural take inside them. So there is a general need for more protection. This level of public support for marine protection can be expected and can be seen in Polling from the Hauraki Gulf Form, Submissions on the recent Waiheke Marine Reserve Proposal and the Live Ocean Barometer 2023.

Most of the names were redacted from the submissions but the organisation names were left public. Here are the names of the organisations that made significant submissions.

OPPOSED PARTIALLY SUPPORT SUPPORT
Legasea
2xs Charters / Balmain Boating Services
Alan Seasprite Charters
CRA 2 Rock Lobster Management Co
Dr Hook Charters
Fisheries Inshore NZ
Kina Industry Council
Mercury Bay Game Fishing Club
NZ Rock Lobster Industry Council
New Zealand Charter Boat Association
New Zealand Sport Fishing Council
Paua Industry Council
Princess Carol Charters
Provider Adventures Ltd
Sea Urchin NZ Ltd
Seahawk Fishing Charters
Slipper Island Residents Association
Snap Attack
Specialty & Emerging Fisheries Group
Tairua Adventures Ltd / Artisan Fishing Co
Te Ohu Kaimoana
Te Ra Charters
The New Zealand Angling & Casting Association
Whitianga / Coromandel Peninsula Commercial Fisherman’s Association
Aldermen Islands Marine Reserve Group
Friends of the Hauraki Gulf
Mama Fish
Sanford Limited
Forest & Bird
Revive Our Gulf
Auckland City Centre Residents Group
Auckland Conservation Board
Auckland Council
Auckland Sea Kayaks
Auckland Sea Shuttles
Coromandel Marine Farmers Association
Devonport Yacht Club
Environmental Defence Society
Foundation North
Friends of Taputeranga Marine Reserve Trust
Goat Island Dive and Snorkel
Good Fishing
Hahei Residents and Ratepayers Association
Leigh Penguin Project
Live Ocean Foundation
Meadowbank School Marine team
Motuora Restoration Society
Mountains to Sea Conservation Trust
New Zealand Conservation Authority
New Zealand Geographic
New Zealand Marine Sciences Society
Ngāti Hei
Ngāti Manuhiri Settlement Trust
Ocean Voyages Inc
Pakiri Community Landcare Group
Pest Free Kaipātiki
Ports of Auckland Limited
Shakespear Open Sanctuary Society Inc
Sir Peter Blake MERC
Stet
Supporters of Tiritiri Matangi
Te Whanau o Pākiri
The Friends of Te Whanganui‐A‐Hei Marine Reserve Trust
The Glass Bottom Boat Whitianga
The Hauraki Gulf Conservation Trust
The Hauturu Supporters Trust
Tāmaki Estuary Protection Society
Tāwharanui Open Sanctuary Society Inc
Waiheke Marine Project
Waikato Regional Council
Wakatere Boating Club
Yachting New Zealand
Most of these submitters were upset about continued bottom impact fishing in the Gulf. Most of the Charter fishers all sent in the same submission. These submitters indicated support for marine protection but did not express that much support for the proposed measures: Most of these submitters wanted more protection than what was proposed and also wanted bottom impact fishing banned.

I have not published the names of many organisations who used the LegaSea form as those submissions contained dramatically less information than those from the above organisations. They were mostly small owner operator companies who are also keen fishers. The big Purse Sein operator Pelco NZ Ltd and Te Ahu wai o Tangaroa sustainable ecological aquaculture did make significant submissions but they did not speak to the protection proposal.

In response to the submissions the Department of Conservation has reduced the amount of protection. Submissions are now open on the Hauraki Gulf / Tīkapa Moana Marine Protection Bill.

P.S. These bottom impact fishing effort maps were made public by Fisheries Inshore NZ and are useful in considering the proposed ‘trawl corridoors’.

Submissions on the Hauraki Gulf Fisheries Management Plan

Over 10,000 submissions on the Hauraki Gulf Fisheries Management Plan are likely to be the largest data set of opinions on fisheries management in Aotearoa and definitely the largest in the Hauraki Gulf Marine Park.

This copy is displayed when asking for public submissions:


Submissions are public information
Note that all, part, or a summary of your submission may be published on this website. Most often this happens when we issue a document that reviews the submissions received.

People can also ask for copies of submissions under the Official Information Act 1982 (OIA). The OIA says we must make the content of submissions available unless we have good reason for withholding it. Those reasons are detailed in sections 6 and 9 of the OIA.

If you think there are grounds to withhold specific information from publication, make this clear in your submission or contact us. Reasons may include that it discloses commercially sensitive or personal information. However, any decision MPI makes to withhold details can be reviewed by the Ombudsman, who may direct us to release it.


I’m disappointed that Fisheries New Zealand has not released all the submissions citing section 18(f) of the OIA—that the information requested cannot be made available without substantial collation or research.

I’m going to read over the submissions provided (which are substantial) before asking for more detail.

My request

FNZ response

Submissions Part 1

Submissions Part 2

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.

Appendix

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.

Omissions

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.

Northern New Zealand dotterel productivity rates

Northern New Zealand dotterel are classified as a Conservation Dependent species, this means that without human help they will go extinct (usually because of predation from introduced predators like rats & cats). So how do you know if your local dotterel are going extinct or not?

Well first you need to work out their productivity rate. Productivity is measured by the average number of chicks fledged per breeding pair (per season). So if you had two pairs and they fledged one chick you can say the site averaged half a chick (0.5) per pair.

Management is considered effective if productivity values are greater than 0.5 for three consecutive years or longer (Dowding & Davis, 2007).

I help manage dotterel at three sites, I can not claim effective management and any of them. This means that over time these sites are a population sink. It’s important to track and share this metric to help conserve the species.