Source: Radio New Zealand
An international start-up has been pushing for regulation changes to allow it to carry out controversial marine carbon storage in New Zealand waters.
The company, Gigablue, says its technology could be game-changing for the climate, with the potential to store ‘gigatons’ of carbon in the deep ocean and create local jobs.
Its latest trial off the Otago coast is underway right now.
But experts in marine science and law are urging New Zealand to proceed with caution, saying that type of technology is hard to prove, hard to measure, and, at worst, unsafe for the environment.
The company says it needs to be able to carry out ocean research to build its evidence base – but wants to be able to generate carbon credits, in order to fund its work.
It says commercial viability is essential but for now it is prioritising the generation of scientific evidence.
Documents released to RNZ under the Official Information Act show that in meetings with the Ministry for the Environment last year, Gigablue proposed changes to marine regulations that would allow it to go ahead without consents.
The company was assisted in its lobbying by former climate change minister James Shaw, who told RNZ the climate crisis was bad “and we should explore all scientific options that might help us to stop it getting even worse”.
Privately, though, officials appeared frustrated as their questions about gaps in the research and evidence base, and how these would be filled, went unanswered for months.
That frustration was shared by the Environmental Protection Agency (EPA), which turned down two applications from the company to carry out research within New Zealand’s exclusive economic zone in late 2025.
It had previously allowed two much smaller sea trials to go ahead.
In documents provided to RNZ, the EPA concluded that Gigablue’s plans to deploy 1000 tonnes of its proprietary particles into the ocean amounted to dumping, which is illegal under domestic and international law.
The agency was also concerned about the environmental effects, and not convinced that the company’s plans amounted to scientific research – for which an exemption can be granted.
However, earlier this year it agreed to “a significantly modified activity”, which began in March and will finish later this week.
Co-founded by four Israeli entrepreneurs, Gigablue says its ‘microalgae carbon fixation and sinking’ (MCFS) technology stimulates a natural cycle where tiny organisms in the water, called phytoplankton, absorb carbon dioxide from the surface ocean through photosynthesis.
When these microalgae die, some sink – taking the carbon into the deep ocean, where slow-moving currents mean it can stay stored for decades, centuries or longer.
In turn, this allows the surface ocean to suck more climate change-inducing carbon dioxide from the atmosphere.
Phytoplankton are at the beginning of the marine food chain and need light and nutrients to grow. Dick (@willapalens), CC BY-NC-SA 2.0, via Flickr
It is one type of marine carbon dioxide removal (mCDR), a growing field of research that proponents say could help to limit or even reverse global warming.
The company said its technology had undergone comprehensive scientific review, and was “measurable, scalable, and environmentally responsible”.
It intends to sell carbon credits for the extra carbon it manages to store, and has already signed an agreement with aviation services provider SkiesFifty to sequester 200,000 tonnes of CO2 by 2029.
However, marine and climate scientists and maritime law experts who spoke to RNZ expressed similar concerns to those voiced by officials.
They said that, based on publicly-available documents, the technology was indistinguishable from ocean fertilisation, a type of carbon removal that involves encouraging algal blooms and is currently commercially prohibited under international protocols.
Gigablue said its technology was neither ocean fertilisation nor marine dumping, and that it had the backing of local scientists.
It claims it can “responsibly scale its technology toward gigaton-level impact”.
But experts said that even if the company could legally go ahead, proving that any marine carbon removal technology actually worked was fraught with difficulty.
They also pressed the need for updated regulations, but said efforts should be focused on allowing genuine research, not commercialisation.
“In theory, it can sequester carbon,” University of Tasmania marine biologist Lennart Bach said. “We have lots of model studies that can show that.”
The difficulty was proving it.
“Whenever I hear gigaton, I’d be very careful.
“I think it needs to be shown [for] one tonne, 1000 tonnes, 10,000 tonnes. And if you show a million tonnes is reasonably feasible, then maybe you can start talking about a gigaton.”
Current regulations a ‘hindrance’
Gigablue first began operating in New Zealand in 2024, when the EPA gave it permission to conduct two small-scale ocean trials to test how its particles would drift and then sink.
It chartered a vessel from crown research institute NIWA (now part of Earth Sciences New Zealand) to carry out the second trial and also contracted the institute to review its methodology.
However, by 2025 it was looking for a more permissive way to conduct its activities, with an eye to selling carbon credits to businesses wanting to offset their emissions – known as the voluntary carbon market.
As well as the contract with SkiesFifty, it recently raised US$20 million (NZ$35m) in venture capital.
ESNZ (formerly NIWA) vessel Kaharoa II was used in Gigablue’s second trial, in October 2024. Supplied / NIWA
The company first met with senior MfE officials, including the ministry’s chief of staff, in early March 2025.
In a follow-up letter, Gigablue co-founder and chief technology officer Sapir Markus-Alford said the current regulations were “a hindrance” to marine carbon removal, because it was so new that it was not recognised in New Zealand’s system.
The company’s suggestion was to make it a new type of ‘permitted activity’ under EEZ regulations, meaning Gigablue’s activities would not need a consent. Further regulatory changes could follow in future.
But officials had identified a problem.
What Gigablue was proposing sounded extremely similar to ocean fertilisation, in which iron (and sometimes other nutrients) is added to areas where it’s scarce – including large parts of the Southern Ocean – to encourage more phytoplankton to grow.
Other than for “legitimate scientific research”, ocean fertilisation is prohibited under international law, via a 2013 amendment to the London Protocol, the main international agreement governing marine dumping.
In 2023, a protocol meeting agreed that ocean fertilisation “has the potential to cause deleterious effects that are widespread, long-lasting or severe”, such as harmful algal blooms and affecting marine food chains.
New Zealand has not ratified the amendment, but agreed to it, and is a member of the protocol. Under domestic EEZ laws, marine geoengineering and marine dumping are also not allowed.
“However, marine scientific research is considered a permitted activity,” one official noted. “The EPA has allowed Gigablue to undertake research in line with these requirements.”
Gigablue says there are crucial differences between its methodology, and ocean fertilisation, and gave RNZ a document prepared by Tonkin + Taylor outlining the distinctions.
Instead of adding iron directly to the ocean, it is ’embedded’ in small particles designed to accumulate the microalgae as it grows – therefore containing and controlling that growth.
The substrate is then meant to sink quickly to the ocean floor before the algae can decay or be eaten.
Gigablue says this method will store much more carbon than just encouraging free-floating phytoplankton blooms.
University of Canterbury law professor Karen Scott, who specialises in marine law, said the description was “clearly ocean fertilisation” under the protocol.
The ban remained non-binding, Scott said. “But it is arguably persuasive in terms of how states should respond to it.”
University of Canterbury marine law professor Karen Scott University of Canterbury
Efficacy evidence ‘top of the list’ – ministry request
In May 2025, MfE officials and Gigablue met for a two-day series of in-person meetings, with Gigablue executives flying in from overseas, joined online by James Shaw and Gigablue’s advisors for Māori engagement.
Personal notes taken by one adviser were punctuated with sceptical remarks about some of the science and environmental claims the company made: “questionable”, “skimmed over” – even “lol”.
Following the meeting, the company provided a summary of the scientific methodology review from ESNZ, along with some studies the company had commissioned from the Nelson-based Cawthron Institute.
After reviewing the documents, the same adviser emailed colleagues with a long list of gaps and assumptions she had identified, for both the environmental effects and for how much carbon would be stored, for how long.
ESNZ had found that the methodology was “scientifically sound and consistent with current scientific understanding of marine carbon dioxide removals”, but stated it had not considered the regulatory framework, environmental thresholds, or the operational scalability, she said.
The Cawthron studies on environmental safety noted “low statistical power” and that the trends should be “interpreted with caution”, she wrote.
Notes from a May meeting with Gigablue show some ministry officials were still sceptical of the company’s claims. RNZ / Kate Newton
There were other ocean-based mCDR start-ups operating overseas, using various different technologies, but they provided “much more public documentation of their methodology and research”, she said.
Not all her colleagues were so sceptical. In emails debriefing the meetings, one senior adviser said she found Gigablue “very inspiring”.
“It’s a cool idea and I found myself very persuaded.”
More emails and phone calls followed, with officials pressing the need each time for further information about existing and planned research.
In early July, a senior official emailed Markus-Alford a page-long list of what the ministry wanted, including high-priority items that officials felt were “unsighted to peer review”.
“The efficacy evidence is top of the list for us,” the official said.
In mid-September, the adviser who had reviewed the initial documents asked her manager if Gigablue had provided “any of the information we requested a few months ago”.
No, he replied. “At this stage until they share anything with us I don’t think we need to be doing anything.”
EPA turned down larger trial
At the same time that Gigablue was engaging with ministry officials, it was also seeking permission from the EPA to go ahead with a much larger trial offshore from Otago, starting in late 2025.
Marine scientific research can go ahead without a consent, but the agency still has to assess whether it meets the criteria for a “permitted activity”.
In Gigablue’s pre-activity notice filed in February 2025, it said the volumes of particles it had used in its two previous field trials – a few tonnes each – had been too small to track into the deep ocean.
This time, it wanted to release up to 1000 tonnes of particles, in five lots.
Modelling showed that by the time the particles made it to the seafloor, they would be “a scant, scattered presence” and were not expected to smother any sea life, the application said.
“Adverse effects on seabirds, fish, zooplankton and marine mammals are also unlikely.”
The authority asked for further information, including a more detailed environmental impact assessment.
The company finally provided a draft summary assessment in late September, but the authority was unmoved.
In a formal notification, the EPA’s compliance manager said the company’s plans – including a second trial it filed details of in August – could not proceed as permitted activities, because the disposal of particles fell within the definition of dumping.
The authority was also concerned the environmental effects were underestimated, and not satisfied that the proposal fell within the definition of marine scientific research.
“That was not the response we were hoping for,” a Gigablue executive wrote back. The planned research would have to stop, “with a significant cost”.
EPA told RNZ its discussions with Gigablue were “ongoing” and the company submitted a “significantly modified activity” in January this year.
That activity was given permission to go ahead, “strictly in accordance with the description provided and that all mitigation measures are fully implemented and adhered to”.
Instead of the 1000 tonnes it proposed releasing last year, the smaller trial involved just 55kg of substrate, contained within ‘pens’ that would drift up to 180km before being collected.
No change – for now
Although it has only so far applied to carry out research, the MfE documents make it clear that Gigablue wanted to start verifying carbon credits.
An early discussion between officials shows some uncertainty about how to define the company’s activities: “Are they still classified as research or have they shifted to commercial?”
In July, Markus-Alford shared its legal advice with officials “to help us understand the legal state of using the data from a scientific experiment activity for the registration of credits”.
In an interview with RNZ, she said all of Gigablue’s planned activities were still research, but it was “essential” to get carbon credits verified to fund voyages, equipment and expertise.
“These are all research activities that need to still be somehow paid [for].”
It was up to New Zealand to decide how to classify that.
“Our conversations with the New Zealand government is to figure out what the regulator in New Zealand will think is most appropriate, and we will follow it.”
Senior marine scientist James Kerry has been following Gigablue’s progress for several years and believes the company should be focusing on smaller-scale, contained trials. Supplied / James Cook University
James Kerry, a senior marine scientist at European NGO OceanCare and adjunct research fellow at Australia’s James Cook University, said there were plenty of much smaller-scale lab or tank-based studies the company should be doing to demonstrate the basics of its approach before it moved to any kind of open ocean trials.
“It’s certainly possible to begin to gain confidence in your claims or in your expectations without going to what was proposed in one of the requests for a permitted activity, which was to deposit a thousand tons of particles in the ocean.”
An MfE spokesperson told RNZ there was no current work happening to change EEZ legislation or to develop a regime for marine carbon dioxide removal.
There had been communication with Gigablue since October over a proposed visit, and the company had provided some further information, which the ministry was reviewing.
The ministry did not have a position on the efficacy or environmental safety of Gigablue’s technology, nor whether it met the definition of either marine geoengineering or ocean fertilisation, a spokesperson said.
Despite the delayed voyages, the benefit for Gigablue of operating in New Zealand – apart from access to the Southern Ocean – was one of perception.
“We actually came to New Zealand because of its strict environmental approach,” Markus-Alford told RNZ.
Gigablue’s website and public material still lean heavily on the involvement of New Zealand agencies.
The website features photos of the ESNZ vessel at sea during the 2024 voyages, and chief oceans scientist Mike Williams – who declined an interview with RNZ – appears in a promotional video.
A sub-heading says Gigablue’s activities are “Permitted by the EPA”.
Gigablue told officials there were added benefits to New Zealand, too, “including job creation, infrastructure investment, and enhanced global positioning”.
James Shaw told RNZ he saw a clear benefit from allowing Gigablue to continue its activities here.
“If the science proves out … then New Zealand will be well-positioned to take an early lead on removing CO2 from the atmosphere in the ocean as well as on land,” he said.
Why New Zealand?
New Zealand was not the only country that Gigablue was interested in operating in, Markus-Akford told RNZ.
“There are countries out there that promote and even have in place already regulatory frameworks to be able to host those activities and to act as leaders in this space.”
However, the company had found “amazing partners” in New Zealand.
“We found here really a treasure of people and communities that we are really enjoying working with.”
Gigablue CTO and co-founder Sapir Markus-Alford says the company was attracted to New Zealand because of its “strict environmental approach”. Supplied / Gigablue
Among them is Cherie Tirikatene (Ngāi Tahu), the Rekohu/Chatham Islands general manager for Māori-led carbon farming organisation Tāmata Hauhā.
Now also Gigablue’s strategic and iwi engagement manager, she got involved when the company sought help consulting with iwi.
What the company wanted to do was “super exciting”, but it was their open and early engagement that won her over.
“I’ve attached my whakapapa to this because I do believe in it and I believe in their authenticity.”
There were huge opportunities from allowing the company to operate in New Zealand, including local jobs and research opportunities for young people, she said.
However, that could all be lost “if this gets too hard”.
“If we were to lose this off our shores and they go to another country to operate, I would be gutted.”
Tirikatene believed the technology was “a game-changer”.
“What we’re proving now is the scale.”
Robust research and monitoring essential – experts
Late last year, in collaboration with the carbon removals monitoring, reporting and verification (MRV) company, Puro.Earth, Gigablue published a 170-page methodology for microalgae carbon fixation and sinking.
That would require field-based measurements at each stage of every deployment, Markus-Alford told RNZ.
“The measurement of this technology is based on ground-truth data, not on modelling.”
Helene Muri, a senior scientist at Norwegian climate and environmental research institute NILU, co-authored a European report late last year into MRV for marine carbon dioxide removal.
“We concluded that no mCDR method today has a sufficiently robust, comprehensive MRV system to support safe, large-scale deployment or crediting,” she said.
“We are still in the knowledge-building phase, not in a stage where large volumes of credits from marine interventions can be considered high-confidence climate solutions.”
Gigablue’s contract to deliver 200,000 carbon credits by 2029 was therefore “very ambitious and, from a scientific standpoint, most likely premature”, Muri said.
Norwegian climate scientist Helene Muri says there is no mature system to monitor, report and verify any kind of marine carbon dioxide removal yet. Stig Larssæther/NTNU, CC BY-SA 4.0, via Wikimedia Commons
The ESNZ scientific review and the Puro.Earth methodology were both important steps, but not sufficient on their own, Muri said.
“They are not a substitute for public, peer-engageable evidence, independent third-party verification, and regulatory judgment on environmental acceptability and legal consistency.”
Gigablue has not yet published any research, though it provided RNZ with the same one-page summary of the ESNZ review that was supplied to MfE, together with the unpublished study from the Cawthron Institute.
It also supplied a full version of the environmental impact assessment it gave to the EPA in draft form, which said the adverse environmental effects were “expected to be low to negligible”.
Last month, it presented at the Ocean Sciences Meeting, the flagship conference for ocean sciences, and Markus-Alford said it had a research paper going through the review process.
She said the company agreed with the need for published research – which is why Gigablue wanted to scale up its activities in New Zealand.
“We are really eager to create those evidence-based results, to be in the ocean, and to prove to anyone … that our activity is safe.”
James Kerry said the collaboration with institutions like ESNZ was positive, but the underlying research and reports had not been made available.
“That makes it difficult for the wider scientific community to assess what was actually evaluated, under what conditions, and how far the conclusions can really be taken,” he said
From what he could see, the research so far had been limited to small-scale field trials and a small set of “relatively limited” lab studies, he said.
“Each of these can provide useful insights, but none of them individually or collectively are anywhere near sufficient to demonstrate that the approach works as intended or is environmentally safe.”
What next?
Markus-Alford said for now, the company was able to proceed with its immediate research plans under the current EEZ regulations.
It still wanted to verify carbon credits, but the timeline for that was “a matter of the developments with the regulations”.
Karen Scott said New Zealand should allow mCDR research to take place in its waters, but it should do it in line with the London Protocol.
That provided “quite a robust international framework” for assessing which research activities could go ahead, which New Zealand should follow.
“That’s not to say that you need to ban it altogether, because there is potential within this,” she said.
“But … we’re a very long way from the stage where you could convincingly deploy it.”
University of Tasmania marine scientist Lennart Bach Supplied / Lennart Bach
Helene Muri said New Zealand and other states should take a “staged and precautionary approach” to any mCDR projects, and resist rapid commercialisation.
Lennart Bach said governments should “constructively regulate” marine carbon dioxide removal.
He believed there was a place for start-ups to be involved, because they were more inclined to test boundaries.
“Working in the space myself academically … we don’t necessarily overthink it, but we also are hesitant to make the next steps,” he said.
The risk was that an “unhinged” start-up could move too fast. “The intent is good. [It’s] the regulation that is missing.”
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– Published by EveningReport.nz and AsiaPacificReport.nz, see: MIL OSI in partnership with Radio New Zealand