Gigablue announced the first close of its Series A at $20 million back in January — revealed at Davos, which tells you something about where the company is positioning itself. The round was led by Planet Ocean Capital, an ocean-climate-technology venture fund, with participation from additional VCs.
The New Zealand mCDR trial we covered earlier today is the same Gigablue. The $20M is funding both that research and a broader scaling push.
What Gigablue Is Building
Gigablue describes its approach as microalgae carbon sinking and fixation. The mechanism:
- Cultivate microalgae in controlled containment systems (their “flower” design — five containment pens around a central ring)
- The algae absorb CO₂ through photosynthesis as they grow
- The biomass — along with sequestered carbon — sinks to the deep ocean when the trial ends
The company’s particles are small cellulose balls embedded with iron and manganese, which serve as growth media and nutrient sources for the algae.
This is distinct from classic ocean fertilisation (adding nutrients directly to open water) in that the biomass is cultivated in a contained system rather than stimulating wild phytoplankton growth. Gigablue says this makes the process more controllable and measurable. Independent scientists say the distinction matters less than whether the carbon actually stays in the deep ocean long-term.
The Permanence Problem
This is the central open question, and it’s not a criticism — it’s the honest state of the science.
When microalgae sink to the deep ocean (below ~1,000m), carbon storage timescales can range from decades to centuries, depending on whether the organic carbon is remineralized by bacteria before it reaches permanent sediments. Deep ocean carbon cycling is complex and location-dependent.
For a carbon removal credit to be worth anything to buyers, permanence needs to be quantified — not assumed. The MMRV framework Gigablue is building (in-situ oceanographic data, environmental DNA sampling, water chemistry analysis, custom deep-sea monitoring tools) is designed to address exactly this. But it’s expensive, technically hard, and the methodology is still being developed.
This is why the New Zealand trial matters. It’s not commercial deployment. It’s data collection to understand whether the permanence and environmental safety case can be made rigorously.
The MRV Challenge at Sea
Measuring carbon removal in the ocean is fundamentally harder than measuring it on land. On land, you can take soil samples at fixed locations. At sea, you’re tracking carbon through a dynamic, three-dimensional system with currents, mixing, biological activity, and temperature gradients — all of which affect carbon fate.
The industry standard for marine CDR MRV doesn’t exist yet. Groups like the Ocean Visions CDR MRV Coalition and academic researchers at WHOI, MIT, and the University of Tasmania are working on it. Gigablue’s monitoring approach is part of this broader field development — their data contributes to the methodological knowledge base, not just their own projects.
Why the $20M Is Well-Spent
The funding isn’t going toward early commercial deployments. It’s going toward answering the questions that determine whether ocean CDR can become a credible, high-integrity market.
Planet Ocean Capital’s thesis, apparently, is that the permanence and MRV problems are solvable — and that getting there first, with robust data, creates significant competitive advantage when buyers eventually come to market.
That’s a reasonable bet. The prize is enormous: if ocean CDR works and can be verified, it’s the only CDR pathway with theoretically unlimited scale. The ocean has absorbed 25-30% of all human CO₂ emissions since the industrial revolution. Deliberately augmenting that capacity — carefully, with full monitoring — could be a significant piece of the climate solution.
Gigablue isn’t there yet. But the $20M is buying them the chance to find out if they can be.
Sources: Gigablue | ESG Today | Radio New Zealand