Global Ocean Accounts Partnership Secretariat · GOAP Technical Guidance on Ocean Accounting · circular
After reading this Circular, conservation finance practitioners and project developers will be able to use Ocean Accounts to structure, verify and report on project-level finance instruments — blue bonds and sustainability-linked securities, debt-for-nature swaps, payments for ecosystem services, blue carbon instruments, parametric insurance and blended finance. For each, Sections 3.1 to 3.4 state which account entries supply the baseline, which supply the KPIs, and which support verification; Table 0 summarises the field. Section 3.7 works a mangrove restoration cost-benefit analysis and Section 3.8 gives a seven-step procedure for a project developer.
Country-level readiness to support these instruments — whether the evidence base, counterfactual, targets and monitoring commitment are in place — is assessed in TG-0.8 Implementation Readiness Assessment Section 3.8 rather than here, and disclosure-framework mapping in TG-1.11 OA and the Private Sector Section 3.3.
The 2025 System of National Accounts recognises sustainable finance as a measurement domain, defining ESG (Environmental, Social, Governance) finance and green finance as components of financial instruments that sustain or improve environmental and social conditions. Ocean Accounts operationalise these concepts for marine contexts by providing the structured data needed to assess ocean-related risks, dependencies, and opportunities. Sustainable ocean finance directly supports SDG 14 (“Life Below Water”) targets, including Target 14.7 on increasing economic benefits from sustainable use of marine resources. The Kunming-Montreal Global Biodiversity Framework Target 15 calls on businesses and financial institutions to regularly monitor, assess, and transparently disclose their nature-related risks, dependencies, and impacts, a requirement that Ocean Accounts can support.
Decision Use Cases
Project-level finance decisions supported by Ocean Accounts include:
Cost-benefit analysis for restoration projects — Using ecosystem service values from Ocean Accounts to assess whether expected benefits of mangrove restoration, seagrass rehabilitation, or coral reef protection exceed project costs over the relevant time horizon.
TNFD-aligned impact reporting — Demonstrating changes in ecosystem condition, extent, and service provision resulting from financed activities, meeting TNFD disclosure requirements for nature-related impacts and dependencies.
Project ROI assessment — Calculating return on investment for blue economy projects by quantifying multiple ecosystem service benefits (carbon sequestration, coastal protection, fisheries habitat, tourism amenity) using comparable monetary valuation methods from TG-2.4 Environmental (including Ecosystem) Goods and Services Section 3.10.
Baseline and counterfactual scenarios — Establishing pre-project conditions and projected no-action baselines against which project impacts can be measured, enabling additionality demonstration required by carbon credit standards and impact investors.
This Circular is relevant to project developers, conservation finance practitioners, sovereign debt managers, development finance institutions, and account compilers supporting sustainable ocean finance initiatives. The guidance builds on the multilateral finance context described in TG-1.7 OA and Multilateral Development Finance, the valuation methods in TG-2.4 Section 3.10 and the guidance on whether and when to value in TG-1.9 Safe Usage of Monetary Valuation, and the ecosystem asset foundations in TG-3.1 Assets. It also supports the ecosystem-specific accounting methodologies in TG-6.2 Mangrove and Coastal Wetland Accounting and TG-6.3 Seagrass Ecosystem Accounting, which provide blue carbon measurement foundations relevant to many of the finance instruments discussed here.
Essential prerequisites:
Helpful background:
Readers approaching Section 1 for the first time should begin with TG-1.0 Ocean Accounting and the Blue/Ocean Economy, the framing circular for the section, which sets out the ocean economy terminology used throughout, what an ocean account can and cannot certify about a blue economy claim, and the map from a policy question to the circular that answers it. It is recommended reading, not a prerequisite.
This Circular addresses how ocean accounts support project-level ocean finance by quantifying asset-level monetary flows, project contributions to social conditions, and ecosystem service returns on investment. In the Ocean Accounts Framework (TG-0.1 Figure 0.1.2):
| Edge | Direction | Description |
|---|---|---|
| E3 | FG1↔SG1 | Monetary flows between assets and economic sectors |
| E5 | FG1→SG2 | Economic contributions to social conditions |
| E9 | SG3→FG1 | Ecosystem services to economy |
Ocean-linked finance instruments differ in risk profile, tenor and the account inputs they require. Table 0 summarises the field; Sections 3.1 to 3.4 treat each instrument in turn.
Table 0: Ocean finance instruments and their account inputs
Parametric insurance. Parametric (or index-based) insurance instruments provide rapid payouts when predefined environmental parameters are triggered, without requiring traditional loss assessment. For ocean contexts, parametric insurance can cover coral reef damage from hurricanes (with payouts triggered by storm intensity thresholds), fisheries losses from harmful algal blooms (triggered by chlorophyll concentration), or coastal flood damage (triggered by sea level or storm surge measurements). Ocean Accounts contribute to parametric insurance design by:
Blended finance structures. Blended finance uses catalytic capital from public or philanthropic sources to mobilise additional private capital for sustainable development. In ocean contexts, blended finance structures typically involve concessional debt or first-loss guarantees from MDBs or philanthropic foundations, combined with commercial investment from private investors. Ocean Accounts support blended finance by providing the common evidence base that all parties in the capital stack can reference: concessional providers use account data to justify the development rationale, whilst commercial investors use the same data for risk assessment and return estimation.
Blue bonds are debt instruments where proceeds are earmarked for ocean conservation, sustainable marine resource management, or ocean-based climate adaptation. Ocean Accounts provide the foundational information architecture needed to structure, monitor, and verify blue bond instruments.
Structuring Blue Bonds with Account Data
Ocean Accounts support blue bond structuring in several ways:
Baseline establishment. Ecosystem extent and condition accounts establish pre-project baselines for marine natural capital assets such as mangroves, seagrass meadows, coral reefs, and fish stocks. These baselines are essential for defining conservation targets and measuring additionality.
Service quantification. Ecosystem service flow accounts quantify the value of services such as coastal protection, carbon sequestration, and fisheries production that blue bond proceeds aim to protect or enhance. The SEEA EA provides internationally recognised methodologies for valuing these services using exchange value concepts consistent with national accounts.
Verifying use of proceeds. Physical supply and use tables track how marine resources and ecosystem services are used, supporting verification that bond proceeds support intended ocean-positive activities.
Measuring outcomes. Time-series account data records changes in ecosystem extent, condition, and service delivery, providing the basis for impact reporting to bondholders and regulators.
Sustainability-Linked Bond Structures
Beyond use-of-proceeds bonds, Ocean Accounts support sustainability-linked bonds (SLBs) where bond characteristics such as coupon rates are tied to achieving pre-defined sustainability performance targets. Account data can inform key performance indicators (KPIs) for ocean-linked SLBs, including:
In the Ocean Accounts Framework (TG-0.1), these project-level monetary flows correspond to Edge E3 (monetary flows between assets and economic sectors). The 2025 SNA recommends compilation of supplementary measures for sustainability-linked debt securities as “of which” items within the financial accounts framework, which facilitates monitoring of these instruments. For the multilateral finance context of SLBs and the blue bond KPI framework, see TG-1.7 OA and Multilateral Development Finance, Section 3.6.
Blue Bond KPI-Account Mapping
Table 1: Blue Bond KPI-Account Mapping
This mapping enables issuers to draw directly on compiled Ocean Accounts when preparing bondholder impact reports. For guidance on compiling the underlying condition and extent accounts referenced in Table 1, see TG-3.1 Assets.
Debt-for-nature swaps involve the restructuring of sovereign debt in exchange for commitments to conservation investments and outcomes. Ocean Accounts provide the technical foundation for quantifying conservation commitments, monitoring implementation, and verifying outcomes in marine debt swaps.
Quantifying Conservation Commitments
When structuring debt-for-nature swaps, parties must agree on the nature and scale of conservation commitments that justify debt relief. Ocean Accounts support this process by providing:
Asset Valuation: Monetary ecosystem asset accounts estimate the present value of expected ecosystem service flows from marine natural capital. These valuations inform negotiations over the conservation value being exchanged for debt relief. For guidance on appropriate valuation methods, see TG-1.9 Safe Usage of Monetary Valuation.
Spatial prioritisation: Spatially explicit extent and condition accounts help identify priority areas for conservation investment, so that debt swap proceeds target areas of highest ecological and economic value.
Commitment Specificity: Account structures provide the precision needed to define specific, measurable, achievable, relevant, and time-bound (SMART) conservation commitments, such as protecting a defined area of mangroves or achieving specified improvements in reef condition scores.
Monitoring and Verification
Post-swap monitoring requires systematic tracking of conservation outcomes over time. Ocean Accounts provide:
Recent Debt-for-Nature Swap Experience
Recent debt-for-nature swaps demonstrate the growing scale and sophistication of these instruments, and the extent to which their design relies on systematic environmental data. The Seychelles debt-for-nature swap (completed 2015-2016) restructured approximately USD 21.6 million of sovereign debt in exchange for marine protected area commitments covering 30 per cent of the country’s exclusive economic zone. Belize (2021) completed a debt conversion that retired USD 553 million of sovereign debt (repurchased at a discount) and refinanced through a USD 364 million blue bond, committing the country to expanding marine protection to 30 per cent of its ocean area and maintaining a marine conservation endowment fund. Ecuador (2023) executed the largest debt-for-nature swap to date, repurchasing approximately USD 1.6 billion (face value) of commercial bonds through a new USD 656 million loan, with conservation commitments for the Galapagos Islands marine reserve.
In each case, the structuring and ongoing monitoring of conservation commitments relied on systematic spatial and biophysical data that Ocean Accounts produce: ecosystem extent baselines, condition indicators, and protected area management effectiveness metrics.
Example: Blue Carbon in Debt Swaps
Coastal and marine ecosystems including mangroves, seagrass meadows, and salt marshes store large quantities of carbon in biomass and sediments. Debt-for-nature swaps increasingly incorporate blue carbon commitments, where Ocean Accounts track:
For detailed methodology on blue carbon accounting, see TG-6.2 Mangrove and Coastal Wetland Accounting and TG-6.3 Seagrass Ecosystem Accounting.
Payments for Ecosystem Services (PES) schemes create financial incentives for maintaining or enhancing ecosystem service provision. In marine and coastal contexts, PES schemes may target services including coastal protection, water quality regulation, fisheries habitat, and carbon sequestration. Ocean Accounts provide the measurement foundation for designing and operating effective ocean PES schemes.
Valuation Foundations for PES
The SEEA EA establishes a hierarchy of valuation methods appropriate for accounting purposes, with a preference for methods based on observable market prices or revealed preferences. For ocean PES schemes, relevant valuation approaches include:
Directly Observable Prices: Where ecosystem services are already traded in markets (e.g., recreational fishing licences, dive permits), observed prices provide exchange values for accounting and PES pricing.
Resource Rent Methods: For provisioning services like fisheries, resource rent calculations estimate the ecosystem contribution to production by deducting labour, capital, and intermediate input costs from gross output value.
Replacement Cost Methods: For regulating services like coastal protection, replacement costs estimate what it would cost to provide equivalent protection through engineered infrastructure.
Productivity Change Methods: For supporting services that enhance economic production (e.g., nursery habitat supporting commercial fisheries), production function approaches estimate the marginal contribution of ecosystem inputs.
For valuation methodology selection, see TG-2.4 Environmental (including Ecosystem) Goods and Services Section 3.10; TG-1.9 Safe Usage of Monetary Valuation covers whether and when to value at all.
Designing Account-Based PES Schemes
Ocean Accounts support PES scheme design by:
Identifying Beneficiaries: Supply and use tables identify economic units that benefit from marine ecosystem services, informing who should pay for service provision.
Quantifying Services: Physical ecosystem service flow accounts measure the quantity of services provided (e.g., tonnes of carbon sequestered, hectares of shoreline protected), informing payment amounts.
Targeting Payments: Spatial accounts identify where ecosystem services are produced and consumed, enabling geographic targeting of payments to providers.
Monitoring Outcomes: Time-series accounts track whether service provision is maintained or enhanced under PES schemes.
Limitations and Considerations
Account compilers should note that the SEEA EA cautions against using PES payment data directly to estimate ecosystem service prices in accounts (para 9.31). In practice, many PES payments function as income support or restoration funding rather than as price signals for specific services, which further limits their direct use in accounting.
Blue carbon ecosystems, particularly mangroves, seagrass meadows, and tidal marshes, sequester carbon at higher rates per unit area than many terrestrial ecosystems. Kelp forests are also highly productive, whilst their role in long-term carbon sequestration remains under active investigation. Carbon finance mechanisms including voluntary carbon markets, compliance markets, and results-based climate finance increasingly target blue carbon. Ocean Accounts provide essential measurement infrastructure for blue carbon finance.
Account-Based Carbon Quantification
Carbon accounts within the Ocean Accounts framework measure:
Carbon Stocks: Total carbon stored in ecosystem biomass and sediments, measured in tonnes of carbon per ecosystem type and location.
Sequestration Flows: Annual carbon uptake and storage by blue carbon ecosystems, providing the basis for calculating annual carbon credits.
Emission Flows: Carbon releases from ecosystem degradation or destruction, informing avoided deforestation/degradation (REDD+) style crediting approaches.
Net Carbon Balance: The difference between sequestration and emissions, indicating whether an ecosystem is a net carbon sink or source.
Verification Requirements
Carbon credit issuance requires measurement, reporting, and verification (MRV). Ocean Accounts contribute to MRV by:
When selecting a crediting standard, project developers should ensure that the chosen methodology aligns with the carbon quantification approaches used in the underlying Ocean Accounts. Several major voluntary carbon market standards have developed or are developing blue carbon methodologies, including the Verified Carbon Standard (VCS, administered by Verra), the Gold Standard, and the American Carbon Registry. These standards differ in their requirements for baseline setting, additionality demonstration, permanence buffers, and leakage assessment. Account compilers can support project developers by ensuring that the physical carbon stock and flow data compiled in Ocean Accounts are structured to meet the data requirements of the relevant crediting standard, whilst maintaining the methodological consistency needed for national-level reporting.
Integration with Ecosystem Service Accounts
Blue carbon ecosystems provide multiple ecosystem services beyond carbon sequestration, including coastal protection, fisheries habitat, and water quality regulation. Ocean Accounts enable integrated valuation across multiple services, informing decisions about:
For ecosystem-specific carbon accounting guidance, see TG-6.2 Mangrove and Coastal Wetland Accounting.
The mapping between ocean account outputs and the TNFD, IFRS S1 and CSRD disclosure requirements is set out in TG-1.11 OA and the Private Sector Section 3.3, which is the single owner of disclosure-framework mapping in this publication. Two requirements are specific to instrument-level finance and are stated here.
Verification requires a method a third party can re-run. Assurance of an impact claim rests on the underlying data being transparent, sourced, time-series consistent and spatially precise enough to tie to the project boundary. Accounts compiled to international statistical standards satisfy this in a way that bespoke project monitoring generally does not, which is the practical reason to build instrument KPIs on account definitions rather than on project-specific metrics.
Covenant metrics must be defined against a compilation cycle, not a calendar. An instrument that requires an annual condition figure from an account compiled triennially will breach on timing rather than on performance. KPIs should name the account, the table, the indicator and the compilation cycle they depend on, and the reporting schedule should be set to follow that cycle. Section 3.6 below sets out which account each instrument type draws on.
Account Components Supporting Project Finance
Project finance instruments draw on multiple Ocean Account components:
Ecosystem Condition Accounts: Provide baseline and monitoring data for ecosystem health indicators referenced in bond covenants, PES agreements, and debt swap commitments. Condition indicators include species richness, structural complexity, water quality parameters, and functional state metrics. For methodology, see TG-3.1 Assets.
Ecosystem Extent Accounts: Track changes in spatial coverage of marine habitats resulting from conservation or restoration investments. Extent changes enable verification of protection commitments in debt-for-nature swaps and blue bonds. Spatial data should be compiled in formats compatible with project boundaries defined in finance agreements.
Ecosystem Service Flow Accounts: Quantify physical and monetary flows of provisioning, regulating, and cultural services. Service flow accounts provide the basis for valuing project benefits in cost-benefit analysis and for structuring PES payment schedules.
Asset Accounts: Record opening stocks, additions, reductions, and closing stocks of marine ecosystem assets. Asset accounts enable net present value calculations used in restoration project appraisal and in valuing conservation commitments for debt swaps.
Key Indicators for Project-Level Decisions
Table 2: Project Finance Indicators from Ocean Accounts
Data Requirements and Sources
Effective project-level application requires fit-for-purpose data at appropriate spatial and temporal resolution:
Spatial resolution: Project boundaries typically range from <1 km² (local restoration sites) to 10,000s km² (large marine protected areas). Account data should be compiled at Basic Spatial Unit (BSU) resolution that enables aggregation to project scales.
Temporal frequency: Finance instruments require baseline measurements (pre-project), implementation monitoring (annual or more frequent), and ex-post evaluation (typically 3-10 years post-project). Account compilation cycles should align with financing instrument reporting requirements.
Data sources: Combining remote sensing (for extent and some condition indicators), field surveys (for detailed biophysical parameters), administrative data (for economic activity and regulatory enforcement), and scientific studies (for service flow quantification and valuation coefficients).
This section presents a synthetic worked example demonstrating how Ocean Accounts data support cost-benefit analysis for a coastal mangrove restoration project. The example is entirely illustrative and uses simplified assumptions to demonstrate accounting logic. Actual project appraisals would draw on site-specific biophysical and economic data.
Project Context
A coastal state proposes to restore 200 hectares of degraded mangrove habitat in a coastal lagoon system. The restoration involves hydrological reconnection, seedling planting, and management of invasive species over a 5-year implementation period. Project costs are estimated at USD 3 million (capital costs) plus USD 200,000 per year (ongoing management) over a 20-year evaluation horizon.
Account-Based Baseline
Ocean Accounts provide pre-project baseline data:
Project Scenario: Ecosystem Changes
Post-restoration trajectory based on comparable restoration projects (Years 0-20):
Ecosystem Service Valuation
Using the methods in TG-2.4 Environmental (including Ecosystem) Goods and Services Section 3.10 and the SEEA Valuation Guidelines:
Coastal Protection Service (Avoided Damage Cost Method, Tier 5)
Mangrove restoration reduces flood risk to 150 coastal properties. Based on flood risk modelling, expected annual damages decline from USD 400,000 (baseline) to USD 100,000 (post-restoration). Annual benefit = USD 300,000/year (reached at Year 10; linear increase Years 0-10).
Blue Carbon Sequestration (Directly Observable Prices, Tier 1)
Restored mangroves sequester carbon at an average rate of 2.5 tC/ha/year over the 20-year horizon (an optimistic assumption reflecting productive restoration sites, whilst typical rates may be 1.0-2.5 tC/ha/year depending on species and site conditions). At 200 ha and a carbon price of USD 15/tCO2e (voluntary market), annual carbon benefit = 200 ha × 2.5 tC/ha/yr × 3.67 tCO2e/tC × USD 15/tCO2e = USD 27,500/year (Years 5-20, zero Years 0-5 due to establishment lag).
Fisheries Productivity Enhancement (Productivity Change Method, Tier 3)
Production function analysis indicates that each 10% improvement in nursery habitat quality increases local fishery catch value by USD 25,000/year. From baseline (10%) to mature condition (90%), the fishery benefit reaches USD 200,000/year (linear increase over 20 years).
Cost-Benefit Analysis Results
Table 3: Project CBA Summary (20-year horizon, 4% discount rate)
Interpretation
On the benefit streams stated above, the NPV is negative (−USD 1.3 million) and the benefit-cost ratio is 0.77: the monetised benefits do not cover the costs over the 20-year horizon. This is not unusual for ecosystem restoration, where non-monetised co-benefits (biodiversity, cultural services, resilience) are material but not captured in exchange-value-based CBA, but it means the monetised result alone does not establish that the project is economically viable.
Table 3 previously reported an NPV of +USD 0.5 million and a benefit-cost ratio of 1.09, which the stated benefit streams do not reproduce; discounted at 4% they give an NPV of −USD 1.3 million, so the table, this interpretation and the sensitivity results have been recomputed.
Sensitivity to Valuation Assumptions
Project viability is sensitive to key assumptions. Sensitivity results reflect re-discounting all benefit and cost streams at the alternative rate:
Account Integration
This CBA draws entirely on Ocean Accounts components:
Project developers preparing finance proposals for multilateral development banks or impact investors can reference this account-based CBA structure to demonstrate alignment with international statistical standards whilst meeting MDB economic analysis requirements described in TG-1.7 OA and Multilateral Development Finance.
Step 1: Define Project Scope and Boundaries
Identify the geographic extent, temporal horizon, and intended outcomes of the financed activity:
Step 2: Establish Account-Based Baselines
Extract pre-project baseline data from Ocean Accounts or compile project-specific accounts:
Consult TG-3.1 Assets for extent and condition account methodology and relevant ecosystem-specific circulars (e.g., TG-6.2 Mangrove and Coastal Wetland Accounting) for detailed measurement guidance.
Step 3: Define Counterfactual and Project Scenarios
Develop “without project” and “with project” scenarios:
Scenario development should be grounded in scientific evidence from comparable projects and ecological understanding of recovery trajectories.
Step 4: Value Ecosystem Service Changes
Apply the valuation methods in TG-2.4 Environmental (including Ecosystem) Goods and Services Section 3.10 to quantify project benefits:
For project-level cost-benefit analysis submitted to multilateral development banks, supplement exchange values from accounts with welfare values as described in TG-1.7 OA and Multilateral Development Finance Section 3.2.
Step 5: Structure Finance Instrument
Design the finance instrument drawing on account data:
For blue bonds:
For debt-for-nature swaps:
For PES schemes:
Step 6: Establish Monitoring and Reporting Framework
Align project monitoring with Ocean Accounts compilation:
Step 7: Prepare Disclosure Documents
Prepare project disclosure materials aligned with TNFD and IFRS standards:
Consult TNFD sector guidance for ocean industries to identify sector-specific disclosure metrics relevant to the project.
A persistent challenge in ocean finance is the gap between ground-level project development and the information requirements of institutional investors. Ocean Accounts bridge this gap by providing a common measurement framework across project stages.
Pipeline development. The project pipeline for ocean finance typically follows a progression from concept to bankability:
Concept stage: Ocean Accounts establish the baseline extent and condition of the target ecosystem and quantify the ecosystem services at stake.
Feasibility stage: cost-benefit analysis draws on monetary valuations of ecosystem services, physical flow data for carbon sequestration estimates, and economic activity data for employment and livelihood projections.
Preparation stage: the impact indicators embedded in financial covenants, the monitoring framework that will verify outcomes, and the baseline data against which performance will be measured all come from compiled accounts.
Transaction stage: account data are referenced in offering documents, prospectuses, or loan agreements. The readiness diagnostic in TG-0.8 Implementation Readiness Assessment Section 3.8 can be used to confirm that the evidence base meets investor requirements.
Bankability assessment. Financial institutions assess bankability against criteria that differ somewhat from development effectiveness criteria. Ocean Accounts contribute to bankability by:
Aggregation for scale. Individual ocean projects are often too small to attract institutional investment directly. Ocean Accounts facilitate aggregation by providing a common measurement framework across projects: when all projects in a bundle use the same accounting classifications, spatial definitions, and reporting formats, the aggregated portfolio can be assessed and monitored using consolidated account data.
The role of intermediaries. Project preparation facilities, conservation finance intermediaries, and national development banks can use Ocean Accounts as a quality standard, requiring that projects in their pipeline compile specified account types before proceeding to transaction stage. This approach ensures consistent evidence quality across the pipeline and reduces the risk of project failure due to inadequate environmental data.
Authors: [To be confirmed]
Reviewers: [To be confirmed]
Cite this report
OA and Project-Level Finance (2026) (GOAP Technical Guidance on Ocean Accounting, TG-1.8, v0.9.1). GOAP Secretariat. https://guidance.oceanaccounts.org/circulars/section-1/1-8-project-finance/
guidance.oceanaccounts.org/circulars/section-1/1-8-project-finance
© 2026 Global Ocean Accounts Partnership Secretariat · CC BY-NC 4.0 · The report, its PDF and this deck are built from the same source.
Swipe on touch screens. Print gives one landscape page per slide. The address keeps the slide number, so a link opens on the right slide. On a phone in portrait the deck becomes a scrolling document.