Ocean-Based Carbon Sequestration for Carbon Sinks

Detailed overview of innovation with sample startups and prominent university research

What it is

Ocean-based carbon sequestration encompasses a spectrum of innovative strategies and technologies that harness the immense capacity of the ocean to absorb and store carbon dioxide (CO2) from the atmosphere. The ocean already acts as a crucial natural carbon sink, absorbing roughly a quarter of all anthropogenic CO2 emissions. Ocean-based carbon sequestration aims to enhance and accelerate this natural process, offering promising pathways to mitigate climate change and achieve negative emissions on a significant scale.

Impact on climate action

Ocean-Based Carbon Sequestration offers a promising solution within Managing Large Carbon Sinks. By leveraging the vast capacity of oceans to absorb and store carbon, this innovation mitigates climate change effects. It enhances global carbon capture efforts, bolstering climate action by reducing atmospheric carbon dioxide levels and preserving marine ecosystems.


  • Biological Carbon Pump: This naturally occurring process involves phytoplankton, tiny marine algae, absorbing CO2 during photosynthesis. When these organisms die, they sink to the ocean floor, effectively sequestering the carbon in deep-sea sediments for millennia.
  • Ocean Alkalinization: By increasing the alkalinity of seawater, we can enhance its capacity to absorb and retain CO2. This can be achieved by adding alkaline minerals like olivine or limestone, which react with dissolved CO2, converting it into stable bicarbonate ions.
  • Artificial Upwelling and Downwelling: Deliberately inducing the upward movement of nutrient-rich deep water (upwelling) stimulates phytoplankton growth, leading to increased CO2 absorption. Conversely, downwelling can transport carbon-rich surface waters to the deep ocean for long-term storage.
  • Seaweed Cultivation: Seaweed is a phenomenal carbon absorber. Large-scale seaweed farming can sequester considerable amounts of CO2, while also providing valuable biomass for biofuels, bioplastics, food, and other applications.

TRL : 3-6

Prominent Innovation themes

  • Electrochemical Ocean Alkalinization: This technique utilizes renewable energy to power electrochemical processes that enhance ocean alkalinity, accelerating the conversion of CO2 into stable bicarbonate ions. This method offers a potentially more sustainable and controllable approach compared to directly adding alkaline minerals to the ocean.
  • Ocean Iron Fertilization: Adding iron to iron-limited ocean regions can stimulate phytoplankton blooms, increasing CO2 uptake. However, this approach requires careful consideration of potential ecological consequences and further research to confirm its long-term efficacy and safety.
  • Enhanced Weathering in Coastal Environments: Spreading finely ground silicate rocks in coastal areas combines enhanced weathering with ocean alkalinization, accelerating carbon sequestration through both terrestrial and marine processes.
  • Biochar Application in Coastal Ecosystems: Introducing biochar, a stable charcoal-like material, into coastal sediments can enhance carbon storage and provide habitat for marine organisms.
  • Marine Permaculture: This approach involves designing and deploying artificial upwelling systems that support the growth of seaweed and shellfish. These systems enhance carbon sequestration while promoting biodiversity and potentially providing sustainable food sources.

Other Innovation Subthemes

  • Phytoplankton Carbon Pump Enhancement
  • Ocean Alkalinization Technologies
  • Artificial Upwelling and Downwelling Methods
  • Seaweed Cultivation for Carbon Sequestration
  • Renewable-Powered Alkalinization Solutions
  • Iron Fertilization Techniques
  • Coastal Enhanced Weathering Strategies
  • Silicate Rock Spreading for Carbon Capture
  • Biochar Application in Coastal Environments
  • Marine Permaculture Systems
  • Electrochemical CO2 Conversion Processes
  • Sustainable Mineral Addition Methods
  • Phytoplankton Bloom Enhancement Techniques
  • Carbon Sequestration in Coastal Sediments
  • Habitat Creation with Biochar
  • Biodiversity Promotion in Ocean Systems
  • Scalable Upwelling System Design
  • Shellfish Cultivation for Carbon Capture

Sample Global Startups and Companies

  • Running Tide:
    • Technology Focus: Running Tide likely specializes in ocean-based carbon sequestration using natural methods, such as marine algae cultivation. They may employ innovative techniques to enhance the growth of carbon-absorbing organisms in ocean ecosystems.
    • Uniqueness: Running Tide stands out for its commitment to leveraging natural processes for carbon sequestration in the ocean, potentially offering more sustainable and scalable solutions compared to traditional carbon capture methods.
    • End-User Segments: Their solutions could appeal to industries looking to offset their carbon emissions, governments seeking to meet climate targets, and organizations investing in carbon-neutral initiatives.
  • Ocean-Based Climate Solutions, Inc.:
    • Technology Focus: Ocean-Based Climate Solutions, Inc. likely focuses on a range of ocean-based solutions for climate mitigation, including carbon sequestration through methods like ocean afforestation, enhanced ocean alkalinity, or ocean iron fertilization.
    • Uniqueness: This company may differentiate itself through its comprehensive approach to ocean-based climate solutions, offering a portfolio of technologies and strategies tailored to different environmental contexts and regulatory frameworks.
    • End-User Segments: Their solutions could be of interest to coastal communities, renewable energy developers, marine conservation organizations, and policymakers looking for innovative approaches to climate change mitigation.
  • Kelp Blue:
    • Technology Focus: Kelp Blue is likely focused on large-scale kelp farming for carbon sequestration and other environmental benefits. They may employ advanced aquaculture techniques and automation to optimize kelp growth and harvesting.
    • Uniqueness: Kelp Blue may be unique in its focus on kelp as a carbon-negative resource, harnessing the natural carbon absorption capacity of marine algae to mitigate climate change while also providing additional ecosystem services such as habitat restoration and marine biodiversity.
    • End-User Segments: Their solutions could appeal to carbon offset markets, renewable energy companies seeking to enhance their sustainability credentials, and coastal communities interested in diversifying their economic activities while promoting environmental stewardship.

Sample Research At Top-Tier Universities

  • Woods Hole Oceanographic Institution (WHOI):
    • Technology Enhancements: WHOI researchers are pioneering technologies for ocean-based carbon sequestration, including the development of advanced sensors and monitoring systems to assess carbon uptake and storage in the ocean. They are also exploring innovative techniques such as ocean fertilization and enhanced weathering to enhance carbon removal efficiency.
    • Uniqueness of Research: WHOI’s research stands out for its comprehensive approach to ocean-based carbon sequestration, combining expertise in marine biology, oceanography, and engineering. They are conducting field experiments to better understand the biological and physical processes that influence carbon sequestration in the ocean and developing predictive models to optimize carbon removal strategies.
    • End-use Applications: The research at WHOI has implications for climate change mitigation and ocean ecosystem management. By enhancing the ocean’s capacity to absorb and store carbon dioxide, these technologies can help mitigate the effects of climate change and ocean acidification while promoting the health and resilience of marine ecosystems.
  • Scripps Institution of Oceanography:
    • Technology Enhancements: Scripps researchers are focusing on developing cost-effective and scalable technologies for ocean-based carbon sequestration, such as artificial upwelling systems and marine algae farms. They are also investigating the potential of biochar production from ocean biomass as a means of long-term carbon storage.
    • Uniqueness of Research: Scripps’ research emphasizes the integration of natural and engineered systems for carbon sequestration in the ocean. They are exploring synergies between biological carbon uptake processes and engineered interventions to maximize carbon removal efficiency while minimizing environmental impacts.
    • End-use Applications: The research at Scripps has applications for carbon offsetting, sustainable aquaculture, and coastal zone management. By harnessing the ocean’s natural carbon uptake capacity and enhancing it through targeted interventions, these technologies can help address climate change while supporting the sustainable use of marine resources.
  • University of Washington’s School of Oceanography:
    • Technology Enhancements: Researchers at the University of Washington are developing innovative approaches to enhance carbon sequestration in the ocean, such as ocean alkalinity enhancement and marine permaculture systems. They are also investigating the potential of deep ocean injection technologies for long-term carbon storage.
    • Uniqueness of Research: The University of Washington’s research stands out for its focus on scalable and sustainable solutions for ocean-based carbon sequestration. They are conducting interdisciplinary research to assess the feasibility and environmental implications of different carbon removal technologies and inform policy decisions.
    • End-use Applications: The research at the University of Washington has implications for climate change mitigation, marine conservation, and sustainable development. By expanding the toolkit of ocean-based carbon sequestration technologies, these efforts can contribute to global efforts to achieve carbon neutrality and protect vulnerable marine ecosystems.

commercial_img Commercial Implementation

Seaweed Cultivation: Seaweed farming is a well-established industry, with numerous companies cultivating seaweed for various applications, including food, fertilizers, and cosmetics. Some companies are exploring the potential of seaweed farming specifically for carbon removal, biofuel production, and bioplastics.