A New Protocol for Carbon Removal via Direct Ocean Capture & Storage

Isometric has released a draft protocol for carbon dioxide removal (CDR) via Direct Ocean Capture & Storage (DOCS) for public consultation. The protocol outlines requirements and procedures for CDR projects that use DOCS technologies.

The ocean is the world’s largest carbon sink, holding around 50 times more carbon dioxide than the atmosphere. Through a natural process called equilibration, the ocean continuously absorbs carbon dioxide from the air. DOCS leverages this process to durably remove carbon dioxide from the atmosphere.

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In DOCS, seawater is drawn into a facility where electrical currents or chemicals are used to separate the dissolved carbon dioxide present in seawater from the water molecules.

Decarbonized water is then returned to the ocean’s surface layer, where it absorbs more atmospheric carbon dioxide through equilibration. This is when carbon removal occurs. The carbon dioxide captured earlier in the process is permanently stored, preventing it from re-entering the atmosphere.

DOCS has significant scaling potential. It does not need large amounts of land, water or, mineral feedstocks. It harnesses the vast carbon storage capacity of the ocean and can also help address ocean acidification, potentially benefiting local marine ecosystems.

This industry-first protocol takes a scientifically rigorous approach to monitoring, reporting, and verification (MRV) for DOCS. To quantify carbon removal this protocol utilizes Isometric's Air-Sea Carbon Dioxide Uptake Module which uses on-site measurements combined with internationally-recognized ocean models to quantify the drawdown of carbon from the atmosphere.

DOCS suppliers can store the removed carbon in a number of ways, according to what best suits their process. Several carbon storage options are available under this protocol, including Saline Aquifers, In-Situ Mineralization, Ex-Situ Mineralization, Carbonation in the Built Environment, and Dissolved Inorganic Carbon in Oceans.

Leading DOCS suppliers Captura, CarbonBlue and, SeaO₂ provided extensive feedback during the development of the protocol.

Steve Oldham, CEO, Captura, said:

“Direct Ocean Capture has tremendous potential to deliver high-volume, low-cost carbon removal. By combining the precise measurability of engineered systems with the vast, natural scalability of the ocean, it offers a uniquely powerful solution. Now, with this first-of-its-kind MRV protocol, Isometric has established the scientific standards needed for third-party verification of carbon credits from Direct Ocean Capture with durable storage. At Captura, we’re proud to see our technology supported by a rigorous framework that gives buyers, investors, and policymakers the confidence to invest in this high-quality carbon removal pathway.”

Dan Deviri, CEO, CarbonBlue, said:

“Earth’s waters are the planet’s largest carbon sink, but rising atmospheric carbon dioxide levels are hindering their natural ability to regulate the climate. At CarbonBlue, we draw excess carbon dioxide out of water, restoring its capacity to absorb more from the atmosphere and enabling any water-utilising infrastructure to become a tool in the fight against climate change.“We’re excited to welcome Isometric’s Protocol for Direct Ocean Capture and Storage, an important step forward for scientific rigor and transparency in this pathway. This protocol will help ensure buyer confidence in DOCS credits and strengthen its position as a pivotal solution for scaling carbon removal.”

Ruben Brands, Founder & CEO, SeaO₂, said:

“Direct Ocean Capture is a highly promising approach to scaling carbon removal by leveraging our most powerful climate ally: the ocean. SeaO₂’s mission is to protect our planet from getting warmer by reducing the concentration of carbon dioxide in the ocean and, indirectly, in the air, while deacidifying our oceans.“We welcome the launch of Isometric’s Direct Ocean Capture and Storage Protocol. A transparent, science-led framework is essential to scaling DOCS responsibly and ensuring the ocean remains one of our greatest allies in the fight against climate change.”

This draft protocol was developed in line with the Isometric Standard and was created in collaboration between Isometric’s in-house Science Team and reviewers from Isometric’s independent Science Network of over 300 scientific experts. Comments on this protocol are welcome from interested buyers, suppliers, and scientists during the 30-day public consultation period which ends on June 27, 2025.