Carbon Solution · Ocean CDR

Marine Carbon —
The Ocean as
Climate Solution

Vivent Carbon pioneers scalable ocean-based carbon removal across three complementary pathways — seaweed cultivation, seagrass restoration, and coastal alkalinity enhancement — working with fishing communities across the Indo-Pacific to turn ocean health into verified carbon income.

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Active ocean CDR technologies
💨
 
tCO₂e pipeline capacity by 2027
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Coastal fishing households engaged
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University MRV research partners
What is Ocean-Based CDR?

The Ocean Absorbs 30% of
Our CO₂. We're Helping It
Do Even More.

The ocean is already the planet's largest active carbon sink — but centuries of pollution, warming, acidification, and coastal habitat destruction have progressively degraded this capacity. Ocean-based carbon dioxide removal (CDR) encompasses a growing portfolio of approaches that work with marine ecosystems to measurably increase the ocean's uptake and long-term storage of atmospheric CO₂.

Vivent Carbon focuses on three community-deployable pathways: seaweed cultivation (macroalgae farmed by coastal communities that sequesters carbon as it sinks or is processed), seagrass restoration (recovering the world's most carbon-dense coastal meadows), and coastal alkalinity enhancement (spreading crushed alkaline minerals in coastal zones to accelerate the ocean's natural carbon chemistry). A fourth pathway — shellfish reef restoration — is in early pilot in Australia.

Vivent is deliberate about MRV rigour for ocean CDR. Unlike well-established land pathways, ocean carbon accounting is an active area of scientific development. We partner with three university research groups (James Cook University, IIT Madras, University of the Philippines Visayas) to build measurement protocols that meet emerging Isometric and Frontier fund standards — and we only issue credits against methodologies that have cleared third-party scientific review.

Our principles for ocean-based CDR

No credits issued until MRV methodology has cleared independent scientific peer review
Community fishing families are primary operators — not external contractors
Co-benefits (fishery health, water quality) measured independently of carbon claims
Transparent uncertainty ranges published with all credit issuances
No open-ocean iron fertilisation or highly speculative geoengineering approaches
All projects designed for ecosystem benefit first, carbon second
Programme Metrics
Active pathways4 (3 issuing)
Seaweed yield2–8 tCO₂e/ha/yr
Seagrass yield4–12 tCO₂e/ha/yr
Alkalinity (coastal)0.5–2.0 tCO₂e/t rock
Typical credit price$60–$280 / tCO₂e
Community revenue share≥ 65%
MRV research partnersJCU, IIT Madras, UPV
Verification Standards
IsometricOcean CDR methodology review
Frontier CDRAdvance market commitment partner
Verra VCSSeagrass methodology (VM0033 ext.)
SBSTA Ocean ProtocolUN ocean CDR framework (draft)
Our Pathways

Four Ways the Ocean
Removes Carbon

Each pathway uses different ocean chemistry and biology — giving buyers access to a diversified, high-integrity ocean carbon portfolio.

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Seaweed Cultivation

Community-operated offshore and near-shore macroalgae farms (Eucheuma, Sargassum, Gracilaria) cultivate fast-growing seaweed that absorbs CO₂ during growth. Carbon is removed when seaweed sinks to depth or is converted to biochar or biostimulant products — preventing decomposition at the surface.

2–8 tCO₂e/ha/yr Issuing credits
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Seagrass Restoration

Seagrass meadows are among the most carbon-dense ecosystems on Earth, storing carbon in both above-ground blades and centuries-deep sediments. Vivent plants native Posidonia, Thalassia, and Cymodocea species in degraded coastal zones, with community divers conducting planting and monitoring across shallow coastal beds.

4–12 tCO₂e/ha/yr Issuing credits
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Coastal Alkalinity Enhancement

Spreading ground olivine, basalt, or calcium carbonate in high-energy coastal zones dissolves minerals that shift ocean chemistry — increasing alkalinity and enabling the ocean to absorb more atmospheric CO₂ while simultaneously counteracting ocean acidification. Community fishing boats deploy material as part of normal sea operations.

0.5–2 tCO₂e/t rock Pilot phase
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Shellfish Reef Restoration

Oyster, mussel, and native shellfish reefs filter seawater, stabilise sediment, and sequester carbon in both shell material and promoted seagrass growth in adjacent areas. Early pilot with Gippsland Fishing Co-operative in Victoria, Australia. MRV framework in development with CSIRO.

TBC tCO₂e/ha/yr Early pilot
How It Works

From Coastal Community
to Verified Ocean Carbon Credit

Ocean CDR requires more scientific rigour than land-based carbon — Vivent builds MRV infrastructure before issuing a single credit.

1
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Site Science & Baseline

Marine biologists and oceanographers conduct site surveys measuring existing carbon stocks, water chemistry, species composition, and hydrodynamics. Baseline dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) measurements establish the additionality baseline.

2
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Community Partnership

Local fishing cooperatives, village councils, and marine protected area management bodies are engaged as project co-owners. Use-right agreements documented. Community members trained as marine technicians and paid as project employees throughout.

3
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Installation & Cultivation

For seaweed: longlines installed, seed stock sourced from local wild populations, community farmers trained in cultivation cycles. For seagrass: community dive teams transplant nursery-raised shoots to prepared sandy substrate. For alkalinity: deployment vessels equipped and schedules established.

4
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Continuous Ocean MRV

Autonomous water quality buoys measure pH, alkalinity, dissolved oxygen, and DIC continuously. Satellite ocean colour imagery tracks biomass. Quarterly sediment cores and biomass harvests calibrate models. All data streamed to Vivent's ocean carbon dashboard in real time.

5
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Scientific Peer Review

Annual data packages submitted to partner universities (JCU, IIT Madras, UPV) for independent analysis. Findings published openly. Any upward revision of carbon accounting methodology requires peer-reviewed evidence before credits are adjusted.

6
Third-Party Verification

Annual verification by Isometric-approved third-party auditors. Uncertainty ranges published with every credit issuance — buyers receive credit certificates showing both central estimate and upper/lower bounds, with clear permanence assumptions.

7
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Community Revenue

≥65% of credit proceeds distributed to participating fishing cooperative members within 30 days of settlement. Seaweed and shellfish product revenue provides additional non-carbon income, reducing dependence on carbon price alone.

8
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Adaptive Management

Annual science review triggers management adjustments — relocating farms away from bleaching zones, adjusting alkalinity application rates based on chemistry feedback, or switching species based on survivorship data. Science drives management, not targets.

Beyond Carbon

Ocean Carbon That
Heals the Sea It Works In

Unlike some CDR approaches, Vivent's marine pathways are designed to improve ocean ecosystem health as a primary outcome — not a side effect.

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Fishery Enhancement

Seaweed farms and seagrass meadows create nursery habitat for commercially important fish and invertebrates. Communities adjacent to pilot sites report 25–60% increases in nearshore catch within 3 years of establishment.

SDG 14SDG 2
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Ocean Acidification Reversal

Coastal alkalinity enhancement directly raises ocean pH, counteracting acidification that is dissolving coral reefs and shellfish exoskeletons. A 0.1 pH unit increase in pilot zones has been measured within 12 months of application.

SDG 14SDG 13
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Marine Biodiversity

Seagrass meadows support dugongs, sea turtles, and critically endangered seahorse species. Seaweed farms provide structural habitat in otherwise bare sandy or degraded seafloor — increasing invertebrate diversity by 180–340% in monitored plots.

SDG 15SDG 14
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Women's Economic Inclusion

Seaweed farming is historically a women-led activity across Southeast Asia. Vivent's programmes formalise and expand this role — 72% of enrolled seaweed farmers are women, with carbon income going directly to their households.

SDG 5SDG 8
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Water Quality

Seaweed and seagrass absorb excess nitrogen and phosphorus from coastal runoff — nutrient pollution that causes destructive algal blooms. Monitored sites show 35–55% reduction in dissolved inorganic nitrogen within established farm zones.

SDG 6SDG 14
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Diversified Coastal Incomes

Seaweed sells into food, cosmetics, and biostimulant markets independent of carbon. Shellfish reefs support artisanal fishing. Carbon credits, seaweed product sales, and fishery income create three independent revenue streams per community.

SDG 1SDG 8SDG 10
Where We Work

Indo-Pacific Ocean Carbon
Programmes

The Indo-Pacific contains over 60% of the world's tropical coastal ecosystems — and some of the highest-potential ocean CDR sites on Earth.

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Philippines — Visayas Seaweed Belt

Eucheuma and Kappaphycus seaweed cultivation across 12 coastal barangays in Cebu, Bohol, and Leyte provinces. Philippines produces 80% of the world's commercial seaweed — Vivent adds carbon MRV to existing farming systems rather than building from scratch.

2,400Seaweed farmers
1,800 haFarm area
IsometricRegistry
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Indonesia — East Java Seagrass Beds

Thalassia hemprichii and Cymodocea rotundata seagrass restoration across degraded beds in the Madura Strait and Gili Islands marine park zone. Community dive teams of 180 trained divers conduct planting and quarterly monitoring surveys.

180Community divers
620 haSeagrass restored
Verra VCSRegistry
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Australia — Gippsland (Pilot)

Shellfish reef restoration and coastal alkalinity enhancement pilot with the Gippsland Fishing Co-operative in Victoria, in partnership with CSIRO Marine and Atmospheric Research. Olivine sourced from existing Australian quarries. MRV framework under development for 2026 credit issuance.

1 pilotSite active
3 yearsMRV timeline
CSIROResearch partner
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Field ReportCebu, PhilippinesYear 2 Results

Cebu Seaweed Belt: 2,400 Farmers, First Ocean Carbon Credits Issued at Scale

Vivent's Cebu seaweed programme launched in 2023, adding a carbon MRV layer to pre-existing seaweed farming operations across 12 barangays in the municipality of San Francisco, Cebu. Rather than establishing new farms, Vivent worked with the existing Cebu Seaweed Farmers Cooperative (2,400 members) to instrument their existing 1,800 ha of longline farms with water quality sensors and biomass tracking protocols.

Year 2 monitoring — verified by Isometric and peer-reviewed by James Cook University — confirmed 8,400 tCO₂e of net ocean carbon removal, representing the first large-scale verified seaweed carbon issuance in the Philippines. Average farmer carbon income was ₱18,200 ($320) in Year 2, supplementing seaweed product sales of ₱42,000 ($740) per household. The programme has attracted follow-on interest from 3 additional cooperatives covering 4,200 additional farmers.

8,400t
tCO₂e verified ocean removal, Year 2
₱18.2K
Average farmer carbon income, Year 2
+3
New cooperatives requesting enrolment
Read Full Case Study →
Common Questions

Marine Carbon Credits — FAQ

This is the right question to ask, and we answer it honestly: seaweed carbon permanence has meaningful scientific uncertainty. A portion of seaweed carbon re-enters the surface ocean as it degrades rather than sinking to depth. Vivent's credits use conservative accounting based on peer-reviewed flux models, and we publish uncertainty ranges with every issuance. Credits are priced to reflect this uncertainty — buyers understand they are getting carefully estimated removal with explicit confidence intervals, not the binary certainty of biochar or enhanced weathering.
Coastal alkalinity enhancement using silicate minerals (olivine, basalt) or calcium carbonate restores ocean chemistry toward pre-industrial conditions — it does not push pH to novel ranges. Studies of natural olivine beaches show no negative ecological impacts at ambient dissolution rates. Vivent's application rates are conservative (well below those used in academic experiments) and all sites are monitored for biological response before scaling. Our CSIRO partnership specifically includes ecotoxicology assessment.
Ocean CDR credits, especially from alkalinity enhancement and seagrass, command premium prices ($60–$280/tCO₂e) because they represent genuine carbon dioxide removal with high permanence — not just avoided emissions. The MRV infrastructure required for ocean carbon (buoy networks, university partnerships, lab analysis) is significantly more expensive than land-based monitoring, and the scientific rigour required to issue high-confidence credits is reflected in the price. For buyers under SBTi or Oxford Principles commitments, this durability class is increasingly required.
Vivent does not participate in and does not intend to pursue open-ocean iron fertilisation. The scientific consensus on permanence, ecosystem disruption risk, and governance concerns for large-scale fertilisation approaches has not reached the bar we require to issue credits. We focus exclusively on coastal CDR approaches where local ecological monitoring is feasible, communities can participate as stewards, and the ecosystem co-benefits are clearly measurable.
Yes, with appropriate context. Isometric and Frontier-verified ocean removal credits are accepted under the SBTi Beyond Value Chain Mitigation framework and Oxford Principles Tier 2 (high-durability removal). We recommend buyers use ocean credits as part of a diversified portfolio alongside nature-based and geological CDR — not as a sole offset pathway. Vivent provides portfolio design support to help buyers construct claims that are both ambitious and defensible.
Ready to Act?

Invest in the Ocean.
The Ocean Will Invest Back.

Vivent's ocean carbon credits are among the most rigorously verified in the voluntary market — backed by university science, community stewardship, and transparent uncertainty accounting.