Innovation & Technology

This Startup Aims to Restore the Ocean’s Power to Store Carbon

Gigablue’s ‘AI-optimized CDR’ approach is designed to re-create the optimal conditions for phytoplankton to play their part in oceanic carbon sequestration, with a goal to sequester 1Gt of CO₂ annually by 2030.

By Scarlett Buckley | Published 1 month ago | About a 7 minute read

Image: FotoshopTofs

The ocean is the most efficient carbon dioxide-removal (CDR) and -storage system we have, absorbing around 30 percent of the CO2 emitted each year. However, the process of transferring carbon from the surface waters to the deep ocean — where it can be safely stored for centuries — is becoming less effective. This is due to changes in ocean conditions including acidification — which inhibits the amount of CO2 absorbed — and temperature and circulation patterns, which make it harder for carbon to sink to the necessary depths.

Phytoplankton — microscopic organisms vital to oceanic carbon sequestration — absorb CO2 from the atmosphere through photosynthesis, turning it into biomass as they grow and reproduce. Though they make up only 1-2 percent of total global plant carbon biomass, they are responsible for capturing about 40 percent of the total CO2 absorbed by the ocean; when phytoplankton die and sink to the ocean floor, they carry atmospheric carbon with them.

Despite their natural efficiency in capturing carbon, this can be inhibited by a deficiency of key nutrients such as iron — which is essential for phytoplankton growth and photosynthesis. In nutrient-poor areas of the ocean, where iron is scarce, phytoplankton’s carbon-absorption capacity is reduced — making it harder for the ocean to effectively sequester it.

To maintain the ocean’s ability to store carbon, we must help move as much carbon as possible from the upper layers — where it interacts with the atmosphere — to the deeper layers, where it can be stored long term.

Enter Gigablue: The New York-based startup specializes in what it calls “AI-optimized CDR” — using advanced AI analysis and biogeochemistry to re-enable the optimal conditions for oceanic carbon sequestration: The company’s geo-specific engineered substrates restore phytoplankton carbon-absorption ability and ensure its descent to the necessary depths for long-term storage. The goal is to sequester one gigaton of CO₂ annually by 2030 by restoring the ocean’s natural capacity as a carbon sink.

Launched in 2022, Gigablue’s four founders — Dotan Levy, Guy Shafran, Sapir Markus-Alford and Ori Shaashua — were united in their vision of amplifying the power of Earth’s most efficient carbon sink to combat climate change on a massive scale, by tapping into the photosynthetic abilities of phytoplankton. They explored, tested and refined numerous concepts before arriving at Gigablue’s unique approach.

“The inspiration was nature itself and its robust mechanisms to attain balance,” CTO Sapir Markus-Alford told Sustainable Brands® (SB). “The ocean is the largest carbon sink in the world, and phytoplankton are some of the most efficient photosynthetic agents in the world. Our vision is to work harmoniously with nature to reverse climate change, and keep our processes safe and respectful to the environment.”

Gigablue’s technology and process

Gigablue’s substrates are tailored to local ecosystems, with a nutrient shell and a weighted core that help phytoplankton grow and sink to the deep ocean, where the carbon they capture can be stored safely for centuries. The substrates are deployed to nutrient-depleted areas called “high nutrient, low chlorophyll” (HNLC) zones to provide the missing nutrients necessary for phytoplankton to effectively absorb and store carbon. The company’s AI prediction engine learns from thousands of deployments and oceanography studies to predict the optimal particle composition for the most favorable locations.

The substrates are produced at Gigablue’s facility in New Zealand and transported by specialized ships to designated deployment zones, at least 100 miles from shore. Once released into the ocean, the substrates help phytoplankton grow and reproduce while ensuring that the carbon they capture sinks to the deep ocean for long-term storage.

Gigablue says one of the benefits of its approach is that the phytoplankton physically attach to the substrate, preventing them from being consumed by larger organisms — such as zooplankton — which typically feed on freely-floating phytoplankton. The substrates are too large for phytoplankton’s predators, essentially creating a “tiny floating farm” where phytoplankton can thrive and continue capturing carbon. This intervention prevents the loss of carbon that would naturally occur through predation, ensuring that more carbon reaches the depths.

Gigablue tracks the substrates from release to the ocean floor — collecting over 50 data points per deployment. The team says the gradual release of CO2 back into the ocean’s cycle stays within its natural capacity — ensuring a safe, controlled process that won’t overwhelm ecosystems. After each deployment, Gigablue allows the targeted areas to restore balance — giving the ocean time to replenish itself before further interventions.

In addition to underwater monitoring, Gigablue conducts global modeling to assess the broader ecological impacts of its interventions. The team studies how nutrient availability might shift in distant ecosystems, like the Mid-Pacific, to ensure their actions in New Zealand won’t disrupt marine life elsewhere. This sets Gigablue’s approach apart from the controversial practice of ocean iron fertilization.

Based on decades of research into how carbon behaves in the deep ocean, Gigablue claims its carbon sequestration has a durability of 1,000 years. Unlike the faster carbon cycle in surface waters, the deep ocean’s slow cycle allows carbon to be stored for centuries to millennia — with dissolved carbon taking hundreds to thousands of years to return to the surface. The company’s approach has been reviewed by New Zealand’s National Institute of Water and Atmospheric Research and is currently under ISO review with Deloitte.

Challenges of scaling

Bringing Gigablue’s carbon-removal technology to market is no small task. It requires a multidisciplinary approach, from scientific research to engineering, and involves navigating a complex regulatory landscape. The company must experiment with materials, refine its processes, and build trust with both customers and regulators.

“Quantifying the entire process and building the protocol to know exactly what we’ve removed is a major challenge. We have to build trust with customers that what we’re doing is real,” Matan Rudis, Gigablue’s Director of Business Development, told SB.

‘Nature’s carbon credit’

While emphasizing that effective climate action requires reducing emissions at the source as much as possible before turning to carbon-removal solutions, Gigablue offers carbon credits through offtake agreements, typically ranging from 50,000 to 200,000 tons per agreement, at 35 percent lower prices than other carbon-removal methods. To verify its carbon removals and issue carbon credits, Gigablue works with leading standard setter and registry Puro.earth.

Earlier this year, global firms Clear Sky and RAIN partnered with Gigablue to accelerate ocean-based carbon removal, scale Gigablue’s technology and manage the distribution of generated carbon credits — particularly for aviation and other hard-to-abate sectors. Earlier this month, SkiesFifty — an investment company dedicated to sustainability in aviation — expanded its partnership with Gigablue to sequester 200,000 tons of CO₂ over the next four years.

“We’re determined to reach a megaton scale in three years and aim for a capacity of 130 million tons per year by 2030,” Rudis asserted. “This gives us hope: The primary resources we’re utilizing are the ocean, gravity and sunlight — all of which are abundant and free. Looking ahead, the global capacity for this methodology is estimated to be between one and 1.5 billion tons annually, if we combine all the different sites where it can be applied.”