42 published companies work on Ocean CDR as their primary pathway (as of 2026-11-04). The full directory has every pathway; the data page has the files.
42companies
12countries
10in Europe
29Active
6Moderate
1Suspect
6Likely dead
Status is estimated from public signals (news, registry activity, job postings, web presence, funding) and re-evaluated regularly. Active recent signals of activity Moderate some signals, limited recent evidence Suspect few or no recent signals Likely dead no detectable activity, which may be wrong
Size: Company size classes follow the EU SME staff thresholds (micro under 10, small 10 to 49, medium 50 to 249, large 250 and more), derived from LinkedIn size bands; exact headcounts are not published.
| Company | Pathway | Method | Country | Status | Size |
|---|---|---|---|---|---|
| Banyu CarbonUses reversible photoacids activated by sunlight to release CO2 from seawater, enabling the ocean to reabsorb atmospheric CO2 while storing… | Ocean CDR | Direct Ocean Removal | United States | Likely dead | Small (10 to 49) |
| BlueGreenApplies proprietary Lake Guard® algaecide formulations to freshwater bodies to kill harmful cyanobacterial blooms, which the company claims… | Ocean CDR | Marine CDR (Other) | United States | Likely dead | Small (10 to 49) |
| BlueShiftMembrane-free redox electrochemical process that processes alkaline industrial waste and seawater to extract critical minerals/REEs while… | Ocean CDR | Direct Ocean Removal | United States | Active | Micro (under 10) |
| BlusinkDeploys engineered porous substrates on the seafloor to catalyze ocean alkalinity enhancement and support rhodolith (coralline algae)… | Ocean CDR | Ocean Alkalinity Enhancement | United Kingdom | Active | Micro (under 10) |
| CapturaUses proprietary bipolar-membrane electrodialysis to extract CO2 from seawater, allowing the ocean to re-absorb atmospheric CO2; captured… | Ocean CDR | Direct Ocean Removal | United States | Active | Medium (50 to 249) |
| Carbon TimeResearches and develops ocean alkalinity enhancement (OAE) methods — primarily olivine rock weathering and electrochemical alkalinity… | Ocean CDR | Ocean Alkalinity Enhancement | France | Active | Micro (under 10) |
| Carbon to Sea InitiativeNon-profit philanthropic initiative that funds scientific research, field trials, MRV protocols, and policy work on ocean alkalinity… | Ocean CDR | United States | Active | Small (10 to 49) | |
| CarbonBluePumps water (sea, brackish, fresh, waste) through a fluidized-bed reactor where dissolved CO2 reacts with calcium hydroxide to precipitate… | Ocean CDR | Direct Ocean Removal | Israel | Active | Small (10 to 49) |
| CarboniferousSinks compressed sugarcane bagasse bales into the anoxic, hypersaline Orca Basin in the Gulf of Mexico, where oxygen-free conditions are… | Ocean CDR | Marine CDR (Other) | United States | Active | Micro (under 10) |
| Caspian Environmental Consortium Ltd.Cultivates local Caspian Sea diatom microalgae in coastal aquaponds using the Brilliant Planet model, then converts biomass to a stable… | Ocean CDR | Kazakhstan | Moderate | Small (10 to 49) | |
| Ebb CarbonUses bipolar membrane electrodialysis to split desalination brine into alkaline and acid streams, returning the alkaline stream to the… | Ocean CDR | Ocean Alkalinity Enhancement | United States | Active | Small (10 to 49) |
| Ecomerit TechnologiesDeveloping the Precipitor, an offshore wind-powered system that electrolyzes seawater and disperses an alkaline mist to react with… | Ocean CDR | Ocean Alkalinity Enhancement | United States | Suspect | Micro (under 10) |
| ElectroceanElectrochemical seawater process that removes CO2, precipitates calcium carbonate, and co-produces hydrogen, packaged with an… | Ocean CDR | United States | Moderate | Micro (under 10) | |
| EquaticUses seawater electrolysis to permanently store atmospheric CO2 as dissolved bicarbonate and solid calcium/magnesium carbonates, while… | Ocean CDR | DAC (Liquid Solvent) | United States | Active | Small (10 to 49) |
| Fiora MaraCultivates kelp on biodegradable open-ocean farms that auto-sink upon maturity to sequester carbon at depth. | Ocean CDR | Marine CDR (Other) | United States | Likely dead | Micro (under 10) |
| GigablueDeploys engineered buoyant/sinking substrates that stimulate native phytoplankton growth and export organic carbon ("marine snow") to the… | Ocean CDR | Marine CDR (Other) | United States | Active | Small (10 to 49) |
| Kepler ReCaptureConceptual design of autonomous offshore spar platforms using OTEC to power combined seawater desalination and CO2 extraction from ocean… | Ocean CDR | Direct Ocean Removal | United States | Active | Small (10 to 49) |
| Lillianah TechnologiesCultivates native diatoms in photobioreactors and releases them into nutrient-polluted coastal dead zones so their silica shells sink and… | Ocean CDR | Marine CDR (Other) | United States | Active | Micro (under 10) |
| LimenetReacts CO2 with hydrated lime and seawater in a reactor to produce an equilibrated calcium bicarbonate solution released to the ocean for… | Ocean CDR | Ocean Alkalinity Enhancement | Italy | Active | Small (10 to 49) |
| Liquid TreesResearches and advocates for ocean iron fertilization (OIF) in high-nutrient, low-chlorophyll ocean regions, and has deployed diatom-based… | Ocean CDR | Ocean Fertilization | United States | Active | Medium (50 to 249) |
| MacrocarbonHarvests free-floating Sargassum macroalgae in the open Atlantic and pyrolyzes the biomass into biochar plus bio-oil/SAF precursors for… | Ocean CDR | Biochar | Spain | Active | Micro (under 10) |
| Marine Permaculture by Climate FoundationSubmersible seaweed cultivation platforms with renewable-powered deep-water upwelling pumps; harvested biomass yields products plus… | Ocean CDR | United States | Active | Small (10 to 49) | |
| MARINIX Ocean Tech ASStimulates marine snow formation via light-spectrum replicator and sensor technology to sink organic carbon into deep-sea sediments, with… | Ocean CDR | Norway | Moderate | Micro (under 10) | |
| NuWa SolutionsDevelops Ocean Alkalinity Enhancement (OAE) projects for verifiable marine CO2 removal, with MRV, safety guardrails, and community-first… | Ocean CDR | Ocean Alkalinity Enhancement | United States | Active | Micro (under 10) |
| OceanNonprofit convener, funder, and knowledge-producer for marine CDR — road maps, accelerator (Launchpad), ecosystem/field-trial databases,… | Ocean CDR | United States | Active | Small (10 to 49) | |
| Ocean Frontier InstituteAcademic research institute running marine CDR science programs (CONVERGE CDR, North Atlantic Carbon Observatory) covering ocean alkalinity… | Ocean CDR | Ocean-based CDR | Canada | Active | Small (10 to 49) |
| Ocean Nourishment CorporationDevelops ocean fertilization technology using a proprietary macronutrient biostimulant (PhytoPlus) deployed from ships/offshore platforms… | Ocean CDR | Ocean Fertilization | Australia | Active | Micro (under 10) |
| Ocean-based Climate Solutions, Inc.Designs and deploys wave-powered artificial upwelling pumps that transport nutrient-rich deep ocean water to the surface to stimulate… | Ocean CDR | United States | Moderate | Micro (under 10) | |
| PhykosDevelops solar-powered, autonomous robotic platforms that grow seaweed in the open ocean and then sink harvested biomass below 1,500 m for… | Ocean CDR | Marine CDR (Other) | United States | Likely dead | Micro (under 10) |
| PlanetaryPlanetary doses purified alkaline minerals (e.g. magnesium/calcium oxide) into coastal seawater via existing power-plant and wastewater… | Ocean CDR | Ocean Alkalinity Enhancement | Canada | Active | Small (10 to 49) |
| Planeteers CDIReactor-based ocean alkalinity enhancement: captures CO2 from point sources (e.g. wastewater plants), reacts it with limestone to form… | Ocean CDR | Ocean Alkalinity Enhancement | Germany | Active | Small (10 to 49) |
| PronoePronoe builds van-sized electrochemical water-treatment units that plug into desalination plant outflows, dissolving crushed limestone into… | Ocean CDR | Ocean Alkalinity Enhancement | France | Active | Small (10 to 49) |
| Salient Direct Ocean CaptureEarly-stage startup developing electrochemical direct ocean capture (DOC) technology to extract dissolved CO2 from seawater. | Ocean CDR | Unknown | Active | Micro (under 10) | |
| Scaled CarbonGrinds silicate rock into sand and adds it to the ocean (oceanic enhanced weathering / OAE) with a proprietary tracer-based MRV method to… | Ocean CDR | Ocean Alkalinity Enhancement | United States | Likely dead | Micro (under 10) |
| ScapeModular coastal seawater reactors that dissolve olivine to permanently store industrial CO2 as bicarbonate while recovering nickel and… | Ocean CDR | United States | Moderate | Micro (under 10) | |
| Sea-UpDeploys wave-energy-powered artificial upwelling pumps with 200-600m fabric tubes and one-way valves to bring nutrient-rich deep water to… | Ocean CDR | Ocean Fertilization | United States | Likely dead | Micro (under 10) |
| SeafieldsFarms and harvests pelagic Sargassum in floating AlgaePonix paddocks, processes it into bioproducts, bales and sinks surplus biomass to the… | Ocean CDR | Marine CDR (Other) | United Kingdom | Active | Small (10 to 49) |
| SeaGenSolar-powered autonomous marine robots (AlgaRay) that collect floating invasive Sargassum seaweed at the surface and submerge it to ~200m… | Ocean CDR | Ocean-based CDR | United Kingdom | Active | Small (10 to 49) |
| SeaO2Electrochemical Direct Ocean Capture (DOCC) that extracts CO2 from seawater using renewable electricity and vacuum, then stores it… | Ocean CDR | Direct Ocean Removal | Netherlands | Active | Small (10 to 49) |
| Ulysses Ecosystem EngineeringAutonomous underwater drones that collect, process, and plant seagrass seeds to restore blue-carbon meadows at scale. | Ocean CDR | United States | Moderate | ||
| VestaDeploys finely ground olivine sand into coastal/nearshore waters to accelerate marine enhanced rock weathering, increasing ocean alkalinity… | Ocean CDR | Ocean Alkalinity Enhancement | United States | Active | Small (10 to 49) |
| VycarbDeploys modular reactors that add alkaline minerals to high-CO2 coastal/river water, converting dissolved CO2 into stable bicarbonate,… | Ocean CDR | Ocean Alkalinity Enhancement | United States | Active | Small (10 to 49) |
No company matches these filters.
AI-maintained, may contain errors. The seed was Grant Faber's CDR company list (January 2026, CC BY-NC-SA 4.0). Descriptions, pathway, status and size class are generated and refreshed by CaptainDrawdown from public signals (news, registries, press releases, web search) and are estimates, not verified facts. Companies marked CDI are portfolio companies of the Carbon Drawdown Initiative. Buyers, academia and companies whose only pathway is afforestation are not published. Corrections and missing companies: info@carbon-drawdown.de. The same data as CSV, JSON and API, licence CC BY-NC-SA 4.0.