After a decade of consultation and compromise on the Hauraki Gulf / Tīkapa Moana Marine Protection Bill the government is proposing last minute changes to allow commercial ring net fishing in two areas. I have provided ministers analysis showing the proposal would compromise the objectives of the marine protection areas. I also asked Fisheries New Zealand for data on ring net fishing. They replied 49 working days later with a partial response, two days after the bill was debated in the house and I had complained to the Ombudsman.
The data provides factual information to support new arguments against the proposal to allow commercial ring net fishing in the proposed protection areas.
Commercial ring net fishers in the Hauraki Gulf catch an average of $26,588 worth of fish in the proposed protected areas, which is only 6.8% of their total Gulf catch (averaging $366,213 annually). In weight, this equates to 17,616 kg or 12.5% of their total catch. This demonstrates that the proposed protected areas account for a small percentage of their overall income, especially considering these fishers also operate on Auckland’s west coast.
The average annual catch from the proposed protected areas is 17,616 kg worth $26,588, which is small compared to the natural variability in catch outside these areas. For example, the catch outside protected areas fluctuates by 35,103 kg and $141,801 across years, far exceeding the potential loss from protection.
2019-2020
2020-2021
2021-2022
2022-2023
Average
Inside protected areas (kgs)
28,051
23,125
9,575
9,713
17,616
Outside protected areas (kgs)
120,961
119,841
108,851
143,954
123,402
Inside protected areas ($)
$28,383
$47,838
$16,280
$13,852
$26,588
Outside protected areas ($)
$297,053
$376,722
$352,221
$438,854
$366,213
Commercial ring net fishing in proposed protected areas of the Hauraki Gulf
The ecological imbalance caused by overfishing kōura (spiny rock lobster) in CRA 2 has led to the proliferation of kina barrens, devastating kelp forests along Northland’s east coast.
Kelp forests in the Hauraki Gulf could be worth up to USD 147,100 per hectare annually, far exceeding the $10.17 million export value of CRA 2. Kina barrens, by contrast, provide no ecological or economic value.
Fisheries New Zealand’s reliance on biased data, such as Catch Per Unit Effort (CPUE), underestimates kōura depletion. Independent research shows kōura populations, even in marine reserves, are well below natural levels.
The proposal to close commercial and recreational kōura fishing in the inner Gulf for 10 years is the largest fisheries closure ever suggested for the Hauraki Gulf Marine Park. However, fisheries independent data shows it’s not enough.
A new biomass target is precedent-setting and a significant step for Ecosystem-Based Management initiated by Sea Change – Tai Timu Tai Pari. A 3x BR target is essential to control kina populations, halt the spread of kina barrens, and restore productive kelp forests.
Independent data must be prioritised, and a precautionary approach adopted, including a full closure of the CRA 2 fishery. Further delays will only worsen environmental and economic losses.
Recreational fishing lobbyists LegaSea are making a last ditch effort to stop the Hauraki Gulf / Tīkapa Moana Marine Protection Bill. Here are ten reasons why Scott Simpson and other MP’s should support the bill as it stands:
eNGO Support for Increased Protection: Environmental groups have consistently asked for more protection than the bill currently provides, indicating that the bill is already a compromise aimed at balancing diverse interests.
Protection to Address Depletion and Habitat Damage: The bill addresses overfishing, habitat destruction, and declines in marine biodiversity in small areas. Lage scale bottom-impact fishing is being delt with through a different process.
Scientific Evidence Supports High Protection Areas (HPAs): While recreational fishers claim there is no evidence to support HPAs, scientific studies worldwide demonstrate that protected areas are fantastic for restoring fish populations and biodiversity.
Minimal Economic Impact on Recreational Fishing: Recreational fishers will still have access to 87.4% of the Gulf for fishing. The HPAs cover a small portion, reducing the impact on fishing activities while promoting long-term marine ecosystem health.
Displacement Concerns Are Overstated: The limited fishing restrictions introduced by the bill are offset by gains in fish abundance in nearby areas, as larger, reproductively mature fish spill over into fished zones, ultimately benefiting fish stocks outside HPAs.
Limited and Controlled Commercial Fishing: The bill may include ring-net fishing in two HPAs compromising their objectives. However, 10 high protection areas and the two marine reserve extensions will be unaffected by the amendment.
Ecosystem Benefits for Seabirds and Marine Species: High Protection Areas will help protect seabird foraging grounds and marine ecosystems, which directly impacts terrestrial food webs and biodiversity on islands in the Gulf.
A Balanced Approach to Sustainable Use: This bill offers a compromise between no-fishing reserves and managed-use areas, establishing a multi-use marine park with regions for both recreational fishing and high protection. This approach meets both conservation and fishing community interests without entirely prohibiting either.
I have asked Fisheries New Zealand for information regarding the proposed concession to allow commercial ring net fishing in two of the High Protection Areas in the Hauraki Gulf / Tīkapa Moana Marine Protection Bill. My understanding is that Ministers may need to debate the concession in the House before the information is available. So I have sent them an early impact analysis.
I don’t know how to solve this problem, so I am writing it up as a public brief for people smarter than me.
Brief for restoring extremely degraded seafloor ecosystems
Soft sediment marine ecosystems support diverse and productive biogenic habitats like shellfish beds, sponge gardens, tubeworm fields, and bryozoan mounds. Direct impacts such as mobile bottom contact fishing, and indirect impacts such as sediment pollution, reduce the function of these habitats. Stopping or reducing the impacting activities can help the habitats recover naturally over many decades. Active restoration (like mussel and oyster seeding) can be done in areas where the habitat is not recovering naturally; however, some environments can be too degraded for these methods.
Problem
In my opinion, at least tens of square kilometres of the Hauraki Gulf Marine Park are too degraded to restore with known techniques. In these extremely degraded areas, the seafloor is very soft, deep mud. It’s not lifeless; there are burrows and infauna present. But the areas would be more diverse and productive if the seafloor was less soft with less sediment in suspension. Even when pollution input has been reduced in these extremely degraded areas, legacy sediment is constantly resuspended – choking filter-feeding animals and smothering photosynthesising plants. It is difficult to visually convey the condition of these ecosystems, as visibility is usually less than 30 cm on a good day.
Solutions
To increase biodiversity in these areas, the benthic enhancement method must be low-cost at scale. This means traditional erect concrete and steel structures are not likely to be the solution. In my opinion, resurfacing the seafloor with demolition rubble or quarried aggregate is too extreme because it kills all the infauna. Anything heavy deployed will immediately sink into the mud, anything lighter than the mud will quickly be covered by sediment. A smarter solution might contain one of these elements:
Local pits or trenches to collect the most mobile sediment.
Dispersed erect artificial shellfish (think horse mussels) to slow benthic currents and allow sediment to fall out of the water column in fields or fences.
Regular deployments of waterlogged woody debris.
Biological concrete structures that grow using elements from the local environment.
Hardened local seafloor sediments (think mudbrick or mudcrete).
Growing dense algae at the surface which will 1) slow currents and surge to reduce resuspension 2) drop fragments for sequestration, feeding invertebrates, collecting sediment and seafloor hardening.
Caution
While these solutions will restore some ecosystem function they will not restore the original ecosystems. Hard surfaces will likely be first colonised by invasive species and the new habitat will offer more ecosystem services but be novel / new. We must first halt the destructive activities that degraded the seafloor ecosystems.
Artificial reefs have significant potential to boost fish populations, even surpassing pre-fished levels or what is possible in marine reserves. However they have a checkered history overseas, with many reefs:
Failing to restore native biodiversity to levels of those of conserved natural reefs (Bracho-Villavicencio et al. 2023).
Creating hard surfaces which are favoured by invasive species (these species often travel to new areas on hard structures) (Gauff et al. 2023).
Created as a convenient way to dispose of something which pollutes the marine environment (E.g. UnderwaterTimes.com 2006). They can also attract polluting activities (Zhang et al. 2019).
When considering building an artificial reef, it is crucial to determine whether it will provide additional habitat to support reef communities or merely function as a Fish Aggregation Device (FAD). Like artificial reefs, FADs are man-made structures which are attract fish to a specific area by providing habitat and shelter for marine life. The problem with FADs is that they decrease local fish populations by concentrating them in one area where they are easily targeted by fishers (Cabral et al. 2014) as illustrated below.
To define the size of the habitat required to avoid FAD functionality, you could base it on the home range of each fish species you want to increase. For example:
The most studied fish in the Hauraki Gulf is the tāmure / snapper, which show high site fidelity to reef habitats. Tāmure in deep soft sediment habitats are quite mobile, with a median distance of 19 km, and some movements up to 400 km. In contrast tāmure in shallow rocky reef habitats have restricted movements, with a median distance of 0.7 km (Parsons et al. 2011). You can see this in small marine reserves with shallow rock reefs, such as the 5 km² Cape Rodney – Okakari Point Marine Reserve (Goat Island), which effectively increase the size and abundance of this species. Additionally, tāmure around mussel farms have been found to be healthier than those in surrounding soft sediment habitats (Underwood 2023). The studied mussel farms were near rocky reefs and covered about eight hectares (200 x 400m).
This means fished artificial reefs should be deployed at hectare scales to avoid acting as population sinks. For tāmure, an area about the size of eight rugby fields is a considerable undertaking, but to avoid your reef functioning as a FAD for fishing, it is essential to spread your structure over a large area. If this sounds more like ‘habitat enhancement’ than an artificial reef, then perhaps that is a better way to frame your design. Of course, this consideration is unnecessary if your artificial reef is not fished.
REFERNCES
Bracho-Villavicencio et al., 2023 https://doi.org/10.3390/environments10070121 A Review of the State of the Art and a Meta-Analysis of Its Effectiveness for the Restoration of Marine Ecosystems. Environments.
Gauff et al., 2023 https://doi.org/10.1016/j.jembe.2023.151882 Unexpected biotic homogenization masks the effect of a pollution gradient on local variability of community structure in a marine urban environment.
Underwood et al., 2023 https://www.aquaculturescience.org/content/dam/tnc/nature/en/documents/aquaculture/AquacultureHabitatComparativeReport.pdf Habitat value of green-lipped mussel farms for fish in northern Aotearoa New Zealand
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.
“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.
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.
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.
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).
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.
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.
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.
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?
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.
