Doc #44 — Fishing Gear: Maintenance, Production, and Substitution

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RECOMMENDED ACTIONS (BY ACTUAL URGENCY)

First weeks (happens naturally via other priorities)

1. Fishing communities continue fishing with existing gear. No specific government intervention required immediately — the gear exists and the fishers know how to use it.

First months

2. Include fishing gear in the national asset census (Doc #8). Inventory all commercial fishing gear held by fishing companies, independent fishers, chandleries, and marine supply retailers. Classify by type: netting (mesh size and material), monofilament line, braided line, hooks (size and type), floats, sinkers, wire rope, pots and traps. Establish the actual stock.
3. Issue gear maintenance and preservation guidance to all fishing operators. Specific instructions for extending the life of synthetic nets, lines, and hardware (see Section 3). The cost of this guidance is near zero; the payoff is months to years of extended gear life.
4. Engage iwi and hapu with traditional fishing knowledge. Maori customary fishing traditions include net-making (kupenga), hook-making (matau), trap construction (hinaki, pouraka), and fisheries management (rahui). These are living traditions held by coastal iwi. Begin knowledge documentation and partnership arrangements for training programmes.
5. Establish priority allocation for fishing gear. Commercial operations providing the highest food yield per unit of gear should receive replacement gear first. Recreational gear supply is a lower priority.

First year

6. Begin harakeke fiber production for fishing applications. Coordinate with the national harakeke fiber programme (Doc #100) to ensure that fishing-grade fiber — specifically fine, high-strength muka suitable for net twine — is included in production targets. Fishing applications require the highest-quality fiber: long staple, clean, well-processed.
7. Commission prototype net-making from harakeke twine. Engage kairaranga (Maori weavers) and experienced net-makers to produce trial kupenga using traditional and adapted techniques. Begin field testing: catch trials, durability assessment, comparison with degrading synthetic nets.
8. Begin hook fabrication from NZ Steel wire. Wire drawing (Doc #105) to produce suitable gauge wire, followed by bending, pointing, and heat treatment in regional blacksmithing operations (Doc #92). Establish hook production at 3–5 regional workshops.
9. Begin hinaki (eel trap) and pot production. These require only locally available materials — willow, manuka, wire mesh from existing stocks or NZ-drawn wire — and traditional or adapted designs. Trap fishing is gear-efficient: one trap fishes continuously with minimal wear.

Years 2–3

10. Scale harakeke net production to supplement depleting synthetic nets. Target: 5,000–20,000 m^2 of netting per year by Year 3 (see Section 5 for production estimates).
11. Establish net-making workshops at 5–10 coastal centres (Northland, Hauraki Gulf, Bay of Plenty, East Cape, Wellington, Nelson/Marlborough, Canterbury, Otago, Southland). Each workshop trains local net-makers and produces nets for the regional fishing fleet.
12. Develop net preservation treatments. Pine tar, tannin-based bark extracts, and tallow treatments to extend harakeke net life in saltwater (see Section 5.5).
13. Establish a hook recycling and resharpening programme. Every lost hook is irreplaceable in the near term. Hooks recovered from caught fish, broken lines, and beach salvage should be collected, resharpened, and redistributed.

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ECONOMIC JUSTIFICATION

Why fishing gear matters

NZ’s marine fisheries are a significant protein source. Pre-event commercial catch was approximately 400,000–430,000 tonnes per year, with an additional 15,000–25,000 tonnes of recreational and customary harvest.² Under nuclear winter conditions, ocean productivity will change — likely declining in some respects (reduced phytoplankton growth from reduced sunlight) and potentially increasing in others (cooler water temperatures may benefit some southern species). The net effect is uncertain, but NZ’s fisheries will remain a substantial food resource.

At roughly 800–1,200 kcal per kg of whole fish (species-dependent), NZ’s pre-event commercial catch represented approximately 320–520 billion kcal per year — enough to provide roughly 175–285 kcal per person per day for NZ’s population of 5 million.³ This is not the entire diet, but it is a critical protein and micronutrient supplement that pastoral farming and cropping cannot easily replace.

The cost of losing fishing capability

If fishing gear depletes and is not replaced, NZ’s marine harvest declines toward what can be caught by shore-based methods alone — a fraction of the current catch. The practical alternative is to replace most marine protein with terrestrial protein — which means more livestock, more pasture pressure, and more competition for agricultural land that is already constrained under nuclear winter (Doc #76, Doc #74). In caloric terms, the fishing sector’s output is equivalent to roughly 400,000–700,000 additional sheep — animals that NZ may not have pasture to support under reduced growing conditions.

Investment required

The gear production programme described in this document requires:

• Harakeke fiber: Approximately 50–200 tonnes of fishing-grade muka per year once at scale (a fraction of the national harakeke program’s target output, Doc #100)
• Steel wire for hooks: Approximately 5–20 tonnes per year (a minor draw on NZ Steel output, Doc #70)
• Labour for net-making: An estimated 100–300 full-time equivalent net-makers at scale, plus 50–100 hook fabricators. Net-making is a skill that can be taught in weeks and practiced by people who cannot do heavy physical work — it was traditionally practiced by both men and women, and by elderly community members.
• Workshop infrastructure: Net-making requires minimal equipment — a loom frame (timber), shuttles (timber or bone), and a gauge stick. Hook-making requires basic blacksmithing tools and a heat source.

Breakeven: The investment pays back as soon as the first net or hook is used — every unit of gear produced domestically extends NZ’s fishing capability beyond what depleting synthetic stocks alone would permit. The labour and material costs are modest relative to the caloric and nutritional return from continued fishing, provided the gear is allocated to productive fishing operations.

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1. NZ’S CURRENT FISHING GEAR STOCKS

1.1 Commercial fishing fleet gear

NZ’s commercial fishing fleet operates approximately 1,200–1,500 vessels, ranging from small inshore trawlers and longliners to large deepwater vessels.⁴ The fleet collectively holds:

• Trawl nets: Heavy-gauge nylon and polyethylene netting, wire rope trawl warps, steel otter boards. Each trawler carries 2–4 complete nets plus repair netting. Trawl nets are subject to heavy wear and typically last 6–18 months of regular use before requiring major repair or replacement.⁵
• Seine nets: Large nylon nets for purse seining and Danish seining. Similar material to trawl nets but different construction.
• Set nets (gillnets): Lighter monofilament nylon netting. Used extensively by inshore fishers. A single commercial set-netter may operate 1,000–3,000 metres of net.
• Longline gear: Monofilament mainline, snoods (branch lines), and thousands of hooks per vessel. A large longliner may set 10,000–30,000 hooks per trip.⁶
• Pots and traps: Steel-framed wire mesh pots for crayfish (rock lobster), primarily on the South Island west coast and around the Chatham Islands. Wooden and wire mesh traps for various species.

1.2 Recreational and customary gear

NZ has an estimated 600,000–900,000 recreational fishers.⁷ Collectively they hold large but diffuse stocks of:

• Monofilament and braided fishing lines (millions of spools)
• Hooks of all sizes (tens of millions)
• Lures, sinkers, floats, swivels, and terminal tackle
• Small nets (cast nets, landing nets, set nets in some regions)
• Recreational pots and traps

This dispersed stock is difficult to inventory but represents a significant national reserve, particularly of hooks and monofilament line.

1.3 Chandlery and retail stocks

Marine supply retailers (Burnsco, Marine Deals, Hunting & Fishing NZ, independent chandleries) hold commercial stocks of netting, line, hooks, and hardware. Wholesale distributors hold additional inventory. The total retail and wholesale pipeline probably represents 3–6 months of normal sales volume — but “normal” consumption will change dramatically under recovery conditions.

1.4 Depletion timeline estimates

Depletion rates depend heavily on the intensity and type of fishing conducted:

Gear type	Estimated NZ stock	Normal replacement rate	Estimated managed life	Key failure mode
Trawl netting	Thousands of nets on vessels + repair stock	6–18 months per net	2–5 years with repair	Abrasion, UV, chafe
Set net (gillnet)	Extensive commercial and recreational stocks	1–3 seasons per net	3–7 years with reduced use	UV degradation, tangles, bio-fouling
Monofilament line	Millions of spools dispersed nationally	Continuous consumption	3–10 years (rationed)	UV embrittlement, abrasion
Hooks	Tens of millions nationally	Continuous loss	5–15 years (with recovery and resharpening)	Corrosion, loss, breakage
Wire rope (trawl warps)	On vessels + marine supplier stocks	1–3 years per set	3–8 years with reduced use	Fatigue, corrosion
Pots and traps	Thousands nationally	2–5 years per pot	5–15 years with repair	Corrosion, structural failure

Important caveat: These are rough estimates. Actual depletion depends on fishing intensity, which depends on food demand, fuel availability (for powered vessels), and the transition to sail and smaller-vessel fisheries. If deepwater trawling ceases due to fuel depletion (likely within 1–3 years under fuel rationing, Doc #143), the heaviest gear consumers — large trawlers — stop operating, and the national gear stock lasts substantially longer. The shift toward inshore fishing with smaller boats, set nets, and longlines is gear-efficient relative to trawling.

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2. NZ FISH SPECIES AND GEAR REQUIREMENTS

Understanding which species NZ will target under recovery conditions determines what gear is needed. The fishery will shift dramatically from the pre-event pattern.

2.1 The shift to inshore

NZ’s pre-event fishery was heavily weighted toward deepwater species — hoki, orange roughy, squid, jack mackerel — caught by large fuel-intensive trawlers operating hundreds of kilometres offshore.⁸ Under fuel rationing, these fisheries become inaccessible within months. The fishery contracts to inshore and coastal species accessible by small boats, sail vessels (Doc #53), and shore-based methods:

High-priority inshore species (accessible with simple gear):

• Snapper (Pagrus auratus): NZ’s most important recreational and inshore commercial species. Caught by hook and line, longline, and set net. Present throughout northern NZ, primarily above the Chatham Rise.⁹
• Tarakihi (Nemadactylus macropterus): Widespread inshore, caught by trawl, set net, and longline.
• Blue cod (Parapercis colias): Important in the South Island, caught by potting and hook and line.
• Flatfish (various species): Set net, trawl (small-scale inshore trawl is feasible from small boats).
• Kahawai (Arripis trutta): Caught by hook and line, seine net. An undervalued species that is abundant and highly catchable.
• Mullet (Mugil cephalus): Caught by net, especially in harbours and estuaries. Historically an important Maori food fish.
• Eel (tuna — Anguilla spp.): Freshwater, caught by traps (hinaki), lines, and spears. Subject of extensive Matauranga Maori (see Section 6).
• Crayfish / rock lobster (Jasus edwardsii): Caught by pots. High food value per unit of effort.

Shore-based and estuary species (no boat required):

• Shellfish: mussels, oysters, paua, pipi, cockles, kina (see Doc #81 for aquaculture)
• Surfcasting species: kahawai, trevally, snapper (northern regions), gurnard, school shark
• Whitebaiting (seasonal, inanga and other Galaxias species): traditional fine-mesh net fishery in river mouths

2.2 Gear implications

The shift to inshore fishing favours gear types that NZ can produce domestically:

• Set nets (for snapper, flatfish, mullet, tarakihi): netting is the most material-intensive requirement. Harakeke netting can substitute for nylon with a performance penalty.
• Hook and line (for snapper, kahawai, blue cod, tarakihi): requires hooks (steel, producible) and line (harakeke twine or residual monofilament). Simplest gear type to produce locally.
• Pots and traps (for crayfish, blue cod, eels): constructible entirely from NZ materials. The most durable and gear-efficient fishing method per unit of catch.
• Seine nets (for mullet, kahawai, herring): larger netting requirement but proven traditional Maori technique using harakeke kupenga.

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3. EXTENDING SYNTHETIC GEAR LIFE

Before NZ needs to produce replacement gear, it should extract the maximum useful life from existing synthetic stocks. Proper maintenance can extend gear life substantially — by an estimated 50–200% depending on the gear type, current maintenance practices, and use intensity — based on general experience in fisheries where gear is maintained vs. not maintained.¹⁰

3.1 Nylon netting

Nylon (polyamide) netting degrades primarily through UV exposure and abrasion.¹¹

UV protection:

• Store nets out of direct sunlight when not in use. A tarpaulin, net shed, or even draping nets under a tree canopy significantly reduces UV degradation.
• Where available, commercial net-dipping compounds (tar-based or resin-based) protect nylon from UV. Existing stocks should be requisitioned and allocated to commercial fisheries.
• After commercial UV protectants are exhausted, pine tar (from charcoal production, Doc #102) or tannin-rich bark extracts (from manuka, kanuka, or radiata pine bark) provide partial UV protection. These are not as effective as commercial treatments but are better than nothing.

Abrasion reduction:

• Avoid dragging nets over rough seabed where possible. Modify fishing methods to reduce bottom contact.
• Inspect nets after each use. Repair small tears and abrasion damage immediately — a small tear becomes a large hole if left unrepaired.
• Rotate nets to distribute wear evenly.

Bio-fouling removal:

• Marine growth (algae, barnacles, tube worms) on nets increases drag, reduces catch efficiency, and accelerates degradation. Clean nets regularly by scrubbing or pressure washing (where water pressure equipment is available). Drying nets in the sun between uses kills fouling organisms and slows regrowth — but balance against UV damage by limiting sun exposure to the minimum needed for drying.

Saltwater management:

• Rinse nets with fresh water after each use if practical. Salt crystals attract moisture and accelerate degradation during storage.

3.2 Monofilament line

Monofilament nylon line degrades through UV exposure, abrasion, and repeated stress cycling.¹²

• Store unused line in cool, dark conditions. UV is the primary degradation mechanism for stored line.
• Inspect line regularly. Monofilament that has become milky, brittle, or shows surface cracks should be downgraded to less critical applications (not discarded — even degraded monofilament is valuable).
• Discard (or repurpose) the first few metres of line on a reel after each trip — this section absorbs the most UV and mechanical stress.
• Re-spool line periodically to relieve memory coils, which concentrate stress at bends.
• Consider converting monofilament set net material to longline snoods when the netting becomes too degraded for net use — the material may still have years of useful life in a different application.

3.3 Hooks

Hooks are small, simple, and last a long time if not lost. The primary loss mechanisms are: snagging on the seabed (by far the largest source of hook loss), corrosion, and breakage.

• Reduce snag losses: Use circle hooks (which set in the jaw, reducing deep hooking and enabling easier retrieval). Avoid fishing over foul ground where possible. Use sacrificial sinker rigs that release the sinker before the hook when snagged.
• Corrosion prevention: Rinse hooks with fresh water after use. Store dry. Oil or grease hooks in storage (tallow or lanolin — Doc #34 — are effective rust preventives).
• Resharpening: A small file or whetstone restores hook points. This extends useful life indefinitely for hooks that are not structurally compromised.
• Recovery: Establish a culture of hook recovery — hooks found on beaches, in caught fish, or in discarded gear should be collected and redistributed. Every hook has value.

3.4 Wire rope and hardware

Stainless steel and galvanised hardware (swivels, snaps, rings, thimbles) lasts for years with basic maintenance. Freshwater rinse and dry storage are sufficient. Wire rope for trawl warps and heavy applications should be inspected for broken strands and fatigue — standard maritime practice (Doc #52).

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4. HOOK FABRICATION FROM NZ MATERIALS

4.1 Materials

Fish hooks require a material that is strong, hard enough to hold a point, and workable into the required shape. Options from NZ materials:

Mild steel wire (from NZ Steel Glenbrook, Doc #70, via wire drawing, Doc #105): The most practical option. NZ Steel’s Glenbrook works produces steel from domestic ironsand via electric arc furnace, and the output includes wire rod that can be drawn to hook-gauge wire (approximately 1–4 mm diameter depending on hook size) using wire drawing equipment (Doc #105). Mild steel hooks must be case-hardened or through-hardened to hold a point and resist bending open under load. The dependency chain runs: ironsand (west coast NZ beaches) to steel billet (Glenbrook) to wire rod (Glenbrook rolling mill) to drawn wire (regional wire drawing) to finished hook (blacksmith workshop).

Spring steel (from salvaged vehicle springs, machinery springs): Higher-carbon steel that holds a point and resists deformation better than mild steel. Requires hot forging to shape and careful heat treatment (hardening and tempering — Doc #70).

Stainless steel: NZ does not produce stainless steel, but existing stainless steel stocks (cutlery, wire, marine hardware) can be reworked into hooks. Limited supply.

Bone and shell (traditional Maori matau): Maori fish hooks were made from bone (including human bone, whale bone, and moa bone historically), paua shell, and wood composite construction. These materials work — they caught fish for centuries — but they are more fragile than steel (bone hooks break under loads that a steel hook of equivalent size would sustain), cannot be barbed as effectively, are limited in minimum practical size, and require more skill to produce in sizes suitable for larger species.¹³ Bone hooks remain relevant for light-line fishing and as a supplement to steel production.

4.2 Steel hook production process

Step 1 — Wire preparation:

Draw NZ Steel wire rod to the required diameter using wire drawing equipment (Doc #105). For general-purpose hooks comparable to modern sizes 1/0 to 6/0, wire of approximately 2–3 mm diameter is required. For smaller hooks (sizes 4–10), wire of 1–2 mm. The wire should be annealed (softened) after drawing to allow bending.

Step 2 — Cutting and bending:

Cut wire to length (approximately 50–100 mm per hook depending on size). Bend to shape using a jig — a steel or hardwood form block with pins that define the hook profile (shank, bend, gape, point). A simple bending jig allows a trained worker to produce hooks at an estimated rate of 50–200 per hour depending on size and complexity — the lower end for large barbed hooks requiring individual filing, the upper end for small simple hooks in batch production.¹⁴ The eye (or spade end) is formed by bending the shank end into a loop or flattening it.

Step 3 — Pointing:

Grind or file the hook point to a tapered, sharp profile. For barbed hooks, a small triangular cut is filed behind the point before final sharpening. Pointing is the most time-consuming step for quality hooks.

Step 4 — Heat treatment:

Heat the finished hook to cherry red (~800°C) and quench in oil or water to harden. Then temper at 200–300°C (draw to a straw or blue colour) to reduce brittleness. The temper is critical — too hard and the hook snaps under load; too soft and it bends open. This is standard blacksmithing practice (Doc #92) but requires attention and consistency for fish hooks, which must balance flexibility with point retention.¹⁵

Step 5 — Corrosion protection:

Without chromium plating or stainless steel, NZ-made hooks will corrode in saltwater. Options:

• Tallow or lanolin coating (Doc #34): provides short-term protection; must be reapplied.
• Tinning (tin plating by dipping in molten tin): if tin is available (from recycled tin cans — the tin coating on steel cans is recoverable). Provides good corrosion resistance.
• Acceptance of corrosion: Historically, uncoated steel hooks were standard in many fisheries. They corrode, but a hook that lasts one season before significant corrosion is still useful. Frequent sharpening addresses minor surface corrosion.

4.3 Production scale

A small workshop of 3–5 workers with a forge, wire drawing capability, and bending jigs could produce 500–2,000 hooks per day depending on size and quality standards. NZ’s national need is uncertain but substantial: pre-event recreational and commercial hook consumption was probably in the range of 10–30 million hooks per year, though this included many hooks lost on the first use (snag losses).¹⁶ Under recovery conditions with reduced fishing intensity but zero imports, an annual production of 1–5 million hooks from 5–10 regional workshops seems a reasonable initial target. This is achievable within the first year if wire supply and workshop capacity are allocated.

4.4 Matau — traditional Maori hooks

Maori matau (fish hooks) represent centuries of refined design, optimised for NZ species and fishing conditions. Several designs are relevant:¹⁷

• Pa kahawai: A composite hook-and-lure designed for kahawai, incorporating a carved bone or shell point lashed to a wooden or bone shank with a feather or fiber lure attached. Highly effective for trolling and casting.
• Circular/curved bone hooks: Made from a single piece of bone, ground and polished to shape. Used for bottom fishing and set-line applications.
• Composite hooks with bone points and wooden shanks: The bone point provides the barb and hook action; the wooden shank provides length and is expendable.

These designs are documented in museum collections (Te Papa, Auckland Museum, Canterbury Museum) and in ethnographic literature.¹⁸ More importantly, some are still made and used by practitioners in Maori fishing communities. The practical value for recovery is that bone and shell hooks can supplement steel hook production, particularly for lighter fishing applications, and the design principles — particularly the pa kahawai trolling lure — are directly applicable to steel hook design. Knowledge documentation is urgent: some matau practitioners are elderly, and their design knowledge — including species-specific optimisations not captured in museum collections — should be documented through video and detailed written instructions as a Phase 1 priority. The same urgency applies to kupenga (net-making) and hinaki (eel trap) construction knowledge held by iwi practitioners.¹⁹

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5. HARAKEKE NET PRODUCTION

5.1 Fiber requirements

Net-making requires the highest-quality harakeke fiber: long staple, fine, clean, consistent, and strong. The muka extraction process described in Doc #100 produces suitable fiber, but net twine demands the top grade — Grade A fiber by the grading system proposed in Doc #100, Section 10.

Net twine specifications (estimated, to be confirmed by testing):

• Diameter: 1–3 mm for gillnet twine; 3–6 mm for seine net twine; 6–12 mm for trawl net twine
• Breaking strength: Minimum 15–30 kg for gillnet twine; 50–150 kg for seine twine; 200+ kg for trawl-grade twine (these are targets based on equivalent nylon net twine specifications, scaled for the lower strength-to-weight ratio of natural fiber)
• Twist: Tightly twisted two- or three-ply construction for dimensional stability and knot security

Fiber quantity per net:

A gillnet of 100 metres length and 3 metres depth, with 100 mm mesh, requires approximately 5–10 kg of finished twine.²⁰ A larger seine net for mullet or kahawai (200 metres long, 10 metres deep, 50 mm mesh) might require 50–100 kg of twine. These are rough estimates that will be refined through prototype production.

5.2 Net construction

Nets are made by knotting twine into a mesh of uniform size. The tools are simple:

• Net shuttle (or netting needle): A flat, elongated tool (timber, bone, or plastic) wound with twine, used to pass twine through the mesh and form knots. Carved from a single piece of hardwood in minutes.
• Mesh gauge: A flat stick or bar of the desired mesh width. Each row of knots is formed around the gauge to ensure uniform mesh size.
• Frame or hanging line: The finished net is hung from a head rope (with floats) and weighted at the bottom (lead line or stone-weighted foot rope).

The knotting technique — the sheet bend knot, universally used in net-making worldwide — is simple to learn and can be taught in hours. Speed comes with practice: an experienced net-maker can tie 15–30 knots per minute, producing approximately 1–3 square metres of net per hour depending on mesh size.²¹

5.3 Kupenga — Maori net-making tradition

Maori net-making (kupenga) is one of the most directly applicable Matauranga Maori traditions for recovery. Large seine nets for communal fishing were among the most important items of material culture produced by coastal iwi.²²

Historical kupenga:

• Seine nets of 100–300+ metres in length were constructed from muka (harakeke fiber) twine for communal fishing of mullet, kahawai, herring, and other schooling species.
• Production was a communal effort — whole hapu participated in fiber extraction, twine spinning, and net construction. A large kupenga might take weeks to months of collective work.
• Net mesh sizes were varied according to target species — finer mesh for small fish, coarser for larger species. This reflects sophisticated understanding of fisheries selectivity.
• Nets were treated with preservatives — tannin-rich bark infusions were used to treat muka nets, extending their saltwater life.²³
• Kupenga were taonga (treasured possessions) that were named, maintained over years, and passed between generations.

Living knowledge: While large-scale kupenga construction is not currently practiced, the knowledge of net-making techniques exists within Maori fishing communities and is documented in ethnographic records. Te Papa Tongarewa holds historical kupenga in its collections, and some iwi maintain net-making as a cultural practice. Engaging these knowledge holders is essential to the recovery net-making programme.

5.4 Production rate estimates

Production stage	Rate per worker	Workers needed for 10,000 m^2/year
Muka extraction (hand)	0.5–1.0 kg/hour	~50–100 (fiber production)
Muka extraction (machine, Doc #100)	100–500 kg/day per machine	2–5 machines with crews
Twine spinning	0.5–2.0 kg/day (hand); 10–50 kg/day (machine)	10–40 (hand spinning) or 1–4 machines
Net knotting	1–3 m^2/hour (experienced)	20–50 full-time net-makers
Finishing (mounting, treatment)	Variable	5–10

Assumption: 10,000 m^2 of finished netting per year is a rough target that might support NZ’s inshore commercial fleet at reduced intensity. This is an estimate — actual requirements depend on fleet size, fishing intensity, and net replacement rate (which depends on how well harakeke nets hold up in service, a critical unknown).

Labour total for net production at scale: Approximately 40–100 full-time equivalent workers for the netting programme alone, plus fiber production labour shared with other harakeke applications (Doc #100). Net-making is labour-intensive but requires relatively little physical strength — historically, net-making was done by men, women, and older community members.

5.5 Net preservation and durability

Untreated harakeke netting in saltwater will degrade through a combination of bacterial action, abrasion, and UV exposure. Service life without treatment is uncertain but probably measured in weeks to months of regular use — significantly shorter than nylon net life of 1–3 years.²⁴

Preservation treatments to extend life:

• Tannin bark treatment (traditional Maori practice): Soaking nets in bark infusions from tannin-rich species — manuka (Leptospermum scoparium), kanuka (Kunzea ericoides), or totara (Podocarpus totara) bark — deposits tannins in the fiber that inhibit bacterial growth and provide modest UV protection.²⁵ This is the most immediately available treatment and can be applied using NZ-native materials without any industrial processing.
• Pine tar treatment: Dipping or painting nets with diluted pine tar provides water resistance and anti-fouling protection. Pine tar is a byproduct of destructive distillation of resinous pine wood (radiata pine is suitable) in charcoal kilns (Doc #102) — the tar condenses from wood smoke during charcoal production and is collected as a liquid. Pine tar was the standard treatment for natural fiber nets and ropes in European fisheries for centuries.²⁶ The treatment adds weight and stiffness — a trade-off against durability.
• Tallow treatment: Rubbing or dipping in melted tallow (Doc #34) provides some water resistance but is less effective than tar for nets because it washes off more readily in active fishing use.
• Drying between uses: The single most effective maintenance practice. Harakeke nets that are thoroughly dried between fishing trips last significantly longer than nets stored wet. This requires net drying racks at landing sites — simple timber frame structures.

Realistic service life (treated harakeke net): With bark or tar treatment and thorough drying between uses, a harakeke gillnet might last 2–6 months of regular fishing use before requiring significant repair or replacement. A heavier seine net, used less frequently, might last 6–12 months. These are estimates — actual performance data must be established through the field testing programme recommended in Action 7. For comparison, nylon gillnets typically last 1–3 seasons (6–18 months) under similar use patterns.²⁷

The performance gap is real but not disabling. Harakeke nets require 2–4 times more frequent replacement than nylon nets, which means producing 2–4 times more netting material per year. This is a significant increase in labour and material demand, but it is feasible given NZ’s harakeke resource.

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6. TRAP AND POT CONSTRUCTION

Traps and pots are the most gear-efficient fishing method available to NZ. A well-constructed pot fishes continuously, requires no operator presence (only periodic checking and rebaiting), loses no hooks or line, and lasts for years with maintenance. They are also constructible entirely from NZ materials.

6.1 Crayfish pots

NZ’s crayfish (rock lobster, Jasus edwardsii) fishery is one of the highest-value inshore fisheries. Pre-event, it used welded steel-frame pots with galvanised wire mesh:

NZ-producible design:

• Frame: Mild steel rod (6–10 mm) bent and welded into a rectangular or D-shaped frame (approximately 600 mm x 400 mm x 300 mm). NZ Steel wire rod (Doc #70) provides the material; welding (Doc #94) or riveting joins the frame.
• Mesh: Galvanised wire mesh (existing stocks or NZ-drawn wire, Doc #105). Alternatively, woven harakeke cord in a coarse mesh pattern — less durable than wire but functional for inshore use.
• Entrance: Conical funnel entrance formed from wire mesh or woven fiber. The funnel design allows entry but impedes exit.
• Bait holder: Wire or woven basket inside the pot to contain bait.
• Rope and buoy: Harakeke rope (Doc #100) connects the pot to a surface float (timber, cork, or sealed container).

A competent welder or blacksmith can fabricate a steel-frame crayfish pot in an estimated 2–4 hours, depending on design complexity and available tooling. Wire mesh covering takes an additional 1–2 hours. Estimated production rate: 2–4 pots per worker per day — this is an engineering estimate based on the fabrication steps involved, not measured production data.²⁸

6.2 Hinaki (eel traps)

Traditional hinaki are woven from flexible plant material:²⁹

• Material: Supplejack vine (Ripogonum scandens) is the traditional preferred material — flexible, strong, and rot-resistant. Manuka branches, willow withies, and harakeke stems are also used.
• Construction: A cylindrical body (approximately 300–600 mm diameter, 600–1,200 mm long) is woven by interlacing flexible rods around a frame of longitudinal stakes. A conical entrance funnel is woven separately and inserted into one or both ends.
• Bait: Earthworms, offal, crushed mussel, or dead fish.
• Setting: Placed in streams, rivers, or lake margins, anchored with stakes or rocks, oriented with the entrance facing downstream (eels travel upstream to feed).

A practitioner experienced in hinaki construction can make one in 2–4 hours from gathered materials. The traps last 1–3 seasons in freshwater depending on material and water conditions.

6.3 Blue cod pots

Blue cod (Parapercis colias), important in southern NZ, is effectively caught with small pots similar to crayfish pots but lighter in construction:

• Frame: Light steel wire or bamboo/manuka framework
• Mesh: Wire mesh or woven cord
• Size: Smaller than crayfish pots (approximately 400 mm x 300 mm x 200 mm)
• Production: Simple enough for community workshop production at rates of 4–8 per worker per day

6.4 Fyke nets

A fyke net is a hoop-and-mesh trap set in shallow water — essentially a net version of a pot, with a series of conical funnels leading into progressively smaller mesh chambers. Fyke nets are used for eels, flatfish, and other bottom-dwelling species in estuaries and rivers. They can be constructed from harakeke netting stretched over bent willow or manuka hoops. A fyke net is more complex to construct than a simple pot but covers more area and can be highly productive in the right habitat.

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7. LINE PRODUCTION

7.1 Harakeke fishing line

Harakeke twine can serve as fishing line for many applications, though with significant performance differences from monofilament:

Property	Harakeke twine (2-ply, ~1.5 mm)	Nylon monofilament (0.4 mm / ~30 lb)
Breaking strength	~15–30 kg	~13.5 kg
Diameter for equivalent strength	~3–5× larger	Baseline
Visibility in water	High (opaque)	Low (translucent)
Water absorption	Significant (heavier wet)	Minimal
Stretch	Low (2–5%)	High (15–25%)
Abrasion resistance	Good	Good
Knot strength	~50–60% of line strength	~70–80% of line strength
UV resistance	Good	Moderate
Production difficulty	Moderate (hand spinning or machine)	Impossible (requires petrochemical feedstock)

Key trade-offs:

• Visibility: Harakeke line is opaque and visible in water. For line-shy species (snapper in clear water, for example), this reduces catch rates compared to monofilament. For less selective species (kahawai, mullet, eels) and for potting/trapping applications where the line is not near the bait, visibility matters less.
• Diameter: The larger diameter of harakeke line for equivalent strength increases drag in water and reduces the number of hooks that can be carried on a longline of given weight.
• Stretch: Low stretch means more transmitted shock from a fighting fish — hooks pull more easily. But it also means better bite detection for hand-line fishing.

Assessment: Harakeke line is adequate for longline mainlines, set-line fishing, pot warps, and general-purpose applications. It is inferior to monofilament for finesse applications (light-line snapper fishing, fly fishing, surfcasting where distance matters). The practical approach is to reserve remaining monofilament for applications where it provides the greatest advantage (light-line, species-selective fishing) and use harakeke for everything else.

7.2 Twisted horse hair and gut leaders

For the lightest and most transparent natural fishing leaders (the short section of line between the hook and the main line), historical options include:

• Horse hair: Twisted or braided horse tail hair was the standard fly-fishing leader material before nylon. NZ has a substantial horse population. Horse hair leaders are fine, relatively transparent, and moderately strong (a three-hair braid breaks at approximately 3–5 kg). Suitable for trout and light saltwater species.³⁰
• Gut (catgut): Processed animal intestine (sheep or cattle gut) can be drawn into a translucent, strong leader material. This is the “gut” of traditional fly-fishing leaders. Production requires careful processing — cleaning, stretching, and drying — but the raw material is abundant in NZ (Doc #117 discusses catgut for surgical suture from the same material).

These are niche applications, but they matter for light-line fishing where line visibility directly affects catch rates — particularly for trout (an important freshwater food source in the South Island).

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8. FLOATS, SINKERS, AND ANCILLARY GEAR

8.1 Floats

• Cork: NZ does not grow cork oak. Existing cork stocks (wine corks, industrial cork) can be repurposed.
• Timber: Small blocks of light, buoyant timber (e.g., balsa is not NZ-native, but totara heartwood, dry pine, or whau — Entelea arborescens, NZ’s lightest native timber — are usable).³¹ Shaped and sealed with tallow, lanolin, or pine pitch.
• Sealed containers: Repurposed plastic bottles and containers make effective floats.
• Traditional Maori floats: Gourd (hue, Lagenaria siceraria) floats were used traditionally on kupenga. Gourd cultivation is feasible in northern NZ.
• Glass floats: If glass production develops (Doc #98), glass net floats — standard in Japanese and NZ fisheries before plastic — are durable and effective.

8.2 Sinkers and weights

• Lead: Recycled lead from batteries, roofing, and plumbing is readily cast into sinker molds (low melting point, ~327°C, castable over a wood fire). NZ’s lead stocks are finite but substantial.
• Stone: Historically universal. Smooth river stones tied to nets with cord.
• Concrete: Small cast-concrete weights for pot anchoring and net weighting.
• Steel: Scrap steel bolts, nuts, and offcuts can serve as sinkers.

8.3 Net needles and tools

All net-making and repair tools are producible from NZ materials:

• Shuttles/needles: Carved from hardwood (totara, beech, puriri) or bone
• Mesh gauges: Flat timber sticks cut to the desired mesh width
• Sail needles (for heavy net repair): Forged steel (Doc #92)
• Marlinspikes and fids: For splicing harakeke rope — turned hardwood or forged steel

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9. CRITICAL UNCERTAINTIES / KEY RISKS

Uncertainty	Why it matters	How to resolve
Total NZ fishing gear stock	Determines depletion timeline and urgency	National asset census (Doc #8)
Harakeke net durability in saltwater under commercial use	Determines net replacement rate and therefore total fiber demand	Field testing programme (Action 7) — begin Year 1
Effectiveness of bark/tar preservation treatments on harakeke nets	Determines achievable net service life	Comparative treatment trials — begin Year 1
Catch rate of harakeke nets vs. nylon nets	Determines whether more netting or different fishing methods are needed to maintain catch levels	Side-by-side fishing trials
Nuclear winter effect on NZ inshore fish stocks	Determines how much fishing effort and gear is needed	Fisheries monitoring programme (MPI/DOC)
NZ Steel wire quality for hooks	Determines hook performance (point retention, fatigue life)	Hook production trials and field testing
Number of practitioners with kupenga and hinaki construction knowledge	Determines training capacity and pace of knowledge transfer	Survey through iwi networks and the National Maori Weavers Collective
Hook loss rate under recovery-era fishing practices	Determines annual hook production requirement	Establish through harvest reporting data
Willingness of iwi to partner on industrial-scale fishing gear programme	Affects access to Matauranga Maori knowledge	Early, genuine engagement — partnership not extraction

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CROSS-REFERENCES

• Doc #1 — National Emergency Stockpile Strategy (gear requisition and allocation)
• Doc #8 — National Asset and Skills Census (fishing gear inventory)
• Doc #34 — Lubricant Production (tallow and lanolin for corrosion protection)
• Doc #70 — NZ Steel Glenbrook (wire rod for hooks and pot frames)
• Doc #78 — Food Preservation (smoking, salting, drying fish — complementary to catching it)
• Doc #81 — Aquaculture (mussel, oyster, and eel farming — complementary to wild-capture fisheries)
• Doc #89 — Hunting and Wild Harvest (marine harvest management framework)
• Doc #91 — Machine Shop Operations (fabrication of net-making equipment)
• Doc #92 — Blacksmithing (hook forging and heat treatment)
• Doc #94 — Welding Consumables (pot and trap fabrication)
• Doc #100 — Harakeke Fiber Processing (fiber supply for nets and lines)
• Doc #102 — Charcoal Production (pine tar for net preservation)
• Doc #105 — Wire and Fencing (wire drawing for hook-gauge wire)
• Doc #138 — Sailing Vessel Design (fishing vessel design and rigging)
• Doc #160 — Heritage Skills Preservation (traditional fishing knowledge documentation)

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FOOTNOTES

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1. Harakeke fiber tensile strength is in the range of 440–990 MPa, comparable to manila hemp (400–980 MPa). See: Carr, D.J., Cruthers, N.M., Laing, R.M., and Niven, B.E., “Fibre from Three Cultivars of New Zealand Flax (Phormium tenax),” Textile Research Journal, Vol. 75(2), 2005, pp. 93–98. https://doi.org/10.1177/004051750507500201 — Also see Doc #100 for comprehensive fiber property data.↩︎

2. NZ commercial fish catch data from Fisheries New Zealand (part of the Ministry for Primary Industries). https://www.mpi.govt.nz/fishing-aquaculture/ — NZ’s total allowable commercial catch (TACC) across all quota management areas is approximately 400,000–430,000 tonnes. Recreational harvest is estimated at 15,000–25,000 tonnes based on MPI survey data, though this figure is uncertain.↩︎

3. Caloric content of fish varies by species and fat content. Lean white fish (snapper, tarakihi, blue cod) provides approximately 800–1,000 kcal per kg of whole fish. Fattier species (kahawai, trevally) provide 1,000–1,200 kcal per kg. Population figure of approximately 5 million from Stats NZ. https://www.stats.govt.nz/↩︎

4. NZ fishing vessel registry data from Fisheries New Zealand. The fleet includes approximately 1,200–1,500 registered commercial fishing vessels, ranging from small (<6 m) inshore dinghies to deepwater trawlers and longliners exceeding 40 m. The number varies as vessels enter and leave the register.↩︎

5. Trawl net service life depends on towing hours, seabed type, and net construction. Industry sources indicate that heavy-use trawl nets require significant repair after 300–500 towing hours and are typically replaced after 1,000–2,000 hours. Source: FAO technical papers on fishing gear technology. https://www.fao.org/fishery/↩︎

6. Longline hook counts from NZ commercial longline fishery data. Large pelagic longliners targeting tuna and swordfish may set 2,000–3,000 hooks per line; bottom longliners targeting snapper and hapuku may set 500–2,000 hooks per line. Multiple lines may be set per trip.↩︎

7. NZ recreational fishing participation from MPI recreational fishing surveys. The 600,000–900,000 estimate is based on survey data indicating approximately 15–20% of the NZ population fishes recreationally at least once per year. See: MPI, “National Panel Survey of Marine Recreational Fishers,” various years.↩︎

8. NZ’s deepwater fisheries are described in detail in NZ Seafood Industry reports and MPI fishery assessments. Hoki, squid, and jack mackerel together account for the majority of NZ’s commercial catch by volume. See: Seafood New Zealand, Industry Profile. https://www.seafood.co.nz/↩︎

9. Snapper distribution and fishery: MPI stock assessment data. Snapper is the most important inshore finfish species in northern NZ (Fishery Management Areas 1, 2, 7, 8, and 9). Stock status varies by area — the Hauraki Gulf / Bay of Plenty stock (SNA 1) has been the subject of extensive management and rebuilding efforts. https://www.mpi.govt.nz/↩︎

10. The 50–200% life extension estimate is based on general fisheries engineering literature on the effect of UV protection, rinse practices, and repair discipline on nylon netting and monofilament service life. See: Klust, G., “Netting Materials for Fishing Gear,” FAO Fishing News Books, 1982, which documents the effect of maintenance on synthetic net durability. The wide range reflects the difference between poorly maintained gear (minimal gain from formalising already-good practices) and gear currently receiving no maintenance at all (where basic UV protection and repair can double or triple useful life).↩︎

11. Nylon netting degradation: Herrmann, B. et al., “Netting materials for trawls and their effect on selectivity,” Reviews in Fish Biology and Fisheries, 2016. UV degradation is the primary aging mechanism for stored nylon; abrasion dominates in active use. Well-maintained nylon netting in NZ inshore conditions typically lasts 1–3 seasons of regular use.↩︎

12. Monofilament degradation: nylon monofilament loses approximately 10–20% of its strength per year under NZ UV conditions when stored in sunlight. Stored in darkness, degradation is much slower — line may remain functional for 5–10+ years. Source: general polymer science literature on nylon UV degradation. See also: fishing tackle manufacturer technical specifications.↩︎

13. Maori matau (fish hooks): Best, E., “Fishing Methods and Devices of the Maori,” Dominion Museum Bulletin No. 12, Government Printer, Wellington, 1929 (reprinted 1977). Extensive documentation of hook types, materials, and construction. Also: Furey, L., “Maori Fishing,” Auckland War Memorial Museum, 1996. Archaeological collections at Te Papa, Auckland Museum, and Canterbury Museum include hundreds of matau spanning centuries of development.↩︎

14. Hook production rate estimate is based on analysis of the fabrication steps (cut, bend, point, heat-treat) and the time each requires with hand tools and jigs. No published production rate data for hand-forged fish hooks in a modern workshop context was identified. The estimate should be validated through the prototype workshop programme recommended in Action 8. Historical industrial hook production (machine-made) achieved far higher rates but is not relevant to the hand-fabrication context described here.↩︎

15. Fish hook heat treatment: standard blacksmithing practice. The balance between hardness (for point retention) and toughness (to prevent snapping) is achieved by quench-hardening followed by tempering to approximately 250–300°C. See: Weygers, A.G., “The Making of Tools,” Van Nostrand Reinhold, 1973 — Chapter on tool tempering. Also: Andrews, J., “The Edge of the Anvil,” Skipjack Press, 1994.↩︎

16. NZ hook consumption data is not publicly reported as a discrete figure. The estimate of 10–30 million hooks per year is inferred from recreational fisher numbers (~600,000–900,000 active fishers using an average of 10–30 hooks per year) plus commercial longline and recreational set-line use. Actual figures should be established through the asset census.↩︎

17. Maori matau (fish hooks): Best, E., “Fishing Methods and Devices of the Maori,” Dominion Museum Bulletin No. 12, Government Printer, Wellington, 1929 (reprinted 1977). Extensive documentation of hook types, materials, and construction. Also: Furey, L., “Maori Fishing,” Auckland War Memorial Museum, 1996. Archaeological collections at Te Papa, Auckland Museum, and Canterbury Museum include hundreds of matau spanning centuries of development.↩︎

18. Maori matau (fish hooks): Best, E., “Fishing Methods and Devices of the Maori,” Dominion Museum Bulletin No. 12, Government Printer, Wellington, 1929 (reprinted 1977). Extensive documentation of hook types, materials, and construction. Also: Furey, L., “Maori Fishing,” Auckland War Memorial Museum, 1996. Archaeological collections at Te Papa, Auckland Museum, and Canterbury Museum include hundreds of matau spanning centuries of development.↩︎

19. Maori fishing traditions: Best, E., “Fishing Methods and Devices of the Maori,” 1929 (see [^12]). Also: Paulin, C.D., “Perspectives of Maori Fishing History and Techniques,” Tuhinga: Records of the Museum of New Zealand Te Papa Tongarewa, No. 18, 2007. Documentation of kupenga, matau, hinaki, pa tuna, and associated tikanga.↩︎

20. Net twine requirements are calculated from mesh geometry: a net of dimensions L × D with mesh size M requires approximately L × D / (M × M) × 4M of twine length (each mesh consists of four half-sides). The weight depends on twine diameter and density. These calculations should be refined based on actual harakeke twine specifications.↩︎

21. Net knotting rates from FAO technical manuals on net-making. An experienced hand net-maker using a shuttle and gauge can tie approximately 15–30 sheet bend knots per minute. Production rates of 1–3 m^2 per hour are typical for medium-mesh netting. See: FAO, “Netting Materials for Fishing Gear,” FAO Fisheries Technical Paper No. 139, 1975.↩︎

22. Maori fishing traditions: Best, E., “Fishing Methods and Devices of the Maori,” 1929 (see [^12]). Also: Paulin, C.D., “Perspectives of Maori Fishing History and Techniques,” Tuhinga: Records of the Museum of New Zealand Te Papa Tongarewa, No. 18, 2007. Documentation of kupenga, matau, hinaki, pa tuna, and associated tikanga.↩︎

23. Bark treatment of harakeke fiber: traditional practice documented in Best, 1929 (see [^12]), and in Pendergrast, M., “Te Aho Tapu: The Sacred Thread,” Reed Books, Auckland, 1987. Tannin-rich barks (particularly manuka, Leptospermum scoparium) were used to treat nets and cordage for extended marine service life. The tannin acts as a preservative and antimicrobial agent — the same principle used in leather tanning.↩︎

24. Natural fiber net durability in saltwater: historical records from European fisheries indicate that tarred natural fiber nets (hemp, flax, cotton) lasted approximately 2–6 months of regular fishing use in temperate waters, compared to 12–36 months for untreated nylon. Source: March, E.J., “Sailing Trawlers,” David and Charles, 1970 — includes discussion of net treatment and service life in pre-synthetic fisheries. Untreated natural fiber nets deteriorated much faster.↩︎

25. Bark treatment of harakeke fiber: traditional practice documented in Best, 1929 (see [^12]), and in Pendergrast, M., “Te Aho Tapu: The Sacred Thread,” Reed Books, Auckland, 1987. Tannin-rich barks (particularly manuka, Leptospermum scoparium) were used to treat nets and cordage for extended marine service life. The tannin acts as a preservative and antimicrobial agent — the same principle used in leather tanning.↩︎

26. Pine tar for net preservation: Stockholm tar was the standard treatment for fishing nets throughout northern Europe for centuries. The tar deposits a water-resistant, antimicrobial layer in the fiber. See: Svensson, S.O., “Traditional Fishing Methods in Scandinavia,” various publications. Also: Hjulstrom, B. and Isaksson, S., “Identification of activity area signatures,” Journal of Archaeological Science, 2009 — discusses tar use in historical contexts.↩︎

27. Nylon netting degradation: Herrmann, B. et al., “Netting materials for trawls and their effect on selectivity,” Reviews in Fish Biology and Fisheries, 2016. UV degradation is the primary aging mechanism for stored nylon; abrasion dominates in active use. Well-maintained nylon netting in NZ inshore conditions typically lasts 1–3 seasons of regular use.↩︎

28. Crayfish pot fabrication time estimate is based on the component steps: frame bending and welding (~1–2 hours), mesh cutting and attachment (~1–2 hours), entrance funnel fabrication (~30–60 minutes), and finishing. Actual production rates will depend on workshop setup, tooling, and worker experience. Pre-event commercial pot manufacturing used jigs and semi-automated processes achieving higher rates; the estimate here assumes basic workshop equipment.↩︎

29. Hinaki construction: Best, E., “Fishing Methods and Devices of the Maori,” 1929 (see [^12]). Also: Hiroa, Te Rangi (Sir Peter Buck), “The Coming of the Maori,” Whitcombe and Tombs, Wellington, 1949 (reprinted Maori Purposes Fund Board, 1982) — Chapter 12 (Fishing) describes hinaki construction in detail. Contemporary hinaki-making is practiced and taught at wananga (learning events) organised by iwi and cultural organisations.↩︎

30. Horse hair fishing leaders: the traditional material for fly-fishing leaders before nylon, documented in fishing literature from Izaak Walton’s “The Compleat Angler” (1653) onward. A three-strand horse hair braid produces a leader of approximately 3–5 kg breaking strength. NZ’s horse population (estimated 60,000–80,000) provides ample raw material. Source: Hills, J.W., “A History of Fly Fishing for Trout,” Philip Allan, 1921.↩︎

31. Whau (Entelea arborescens): NZ’s lightest native timber (specific gravity approximately 0.2–0.3 when dry), used traditionally by Maori for fishing net floats and for raft construction. Grows in coastal and lowland forest throughout the North Island and northern South Island. See: Brooker, S.G., Cambie, R.C., and Cooper, R.C., “New Zealand Medicinal Plants,” Heinemann, Auckland, 1981. Also: Te Ara — The Encyclopedia of New Zealand, entry on whau.↩︎