Global Ocean Accounts Partnership Secretariat · GOAP Technical Guidance on Ocean Accounting · circular
This Circular provides guidance on deriving multilateral environmental agreement (MEA) indicators from ocean accounts, enabling countries to report against international commitments through a unified data infrastructure. Readers will understand how ocean accounts support indicator compilation for Sustainable Development Goal 14 (Life Below Water), the Kunming-Montreal Global Biodiversity Framework (GBF), the Paris Agreement under the United Nations Framework Convention on Climate Change (UNFCCC), and the Agreement on Biodiversity Beyond National Jurisdiction (BBNJ).
Decision-makers will be equipped to use ocean accounts for tracking progress against GBF Target 3 (30x30 protection), SDG 14 targets on marine pollution and fish stocks, Paris Agreement nationally determined contributions (NDCs) for blue carbon and ocean-climate linkages, and emerging BBNJ requirements for areas beyond national jurisdiction.
This Circular requires familiarity with:
Related Circulars that provide supporting guidance:
The ocean domain is addressed by multiple overlapping MEAs. The overlap risks fragmented and duplicative reporting where each agreement is served by a separate data exercise, but it also allows a single account to satisfy several reporting obligations at once. SEEA Ecosystem Accounting (SEEA EA) was adopted by the United Nations Statistical Commission in March 2021 as the international statistical standard for ecosystem accounting. The preface explicitly recognises that the framework will “inform international initiatives and global reporting frameworks, including the Sustainable Development Goals, the Kunming-Montreal Global Biodiversity Framework…and the measurement of GHG emissions and removals by land use, land-use change and forestry (LULUCF) under the United Nations Framework Convention on Climate Change”.
This section examines how ocean accounts can support indicator derivation for the major MEAs relevant to marine ecosystems. Section 3.1 provides an overview of the MEA indicator framework and SEEA’s role. Sections 3.2 through 3.5 address specific agreements: SDG 14, CBD/GBF, UNFCCC/Paris Agreement, and the BBNJ Agreement. Section 3.6 presents an expanded worked example demonstrating the compilation procedure for deriving MEA indicators from ocean account data. Section 3.7 provides a reporting frequency harmonisation note.
Indicators are essential tools for monitoring progress toward environmental goals. The SEEA EA describes indicators as “summary measures related to a key issue or phenomenon and derived from a series of observed facts”. Indicators derived from accounting frameworks benefit from the coherence and consistency that accounts provide, as the underlying data have been reconciled and harmonised across multiple sources. Figure 2.10.1 illustrates how a single SEEA-based ocean account, compiled once, can serve multiple multilateral instruments simultaneously.
· Figure 2.10.1
Source TG-2.10 draft §3.1 (MEA reporting matrix) and §3.5 (BBNJ condition- and service-based environmental impact assessment); SEEA EA §3.30-3.54 (extent), §3.55-3.78 (condition).
Chapter 14 of SEEA EA identifies three main types of indicators that can be derived from ecosystem accounts, as summarised in Table 3.1.1 below.
The SEEA EA notes that indicators derived from accounting frameworks offer several advantages:
The combined presentations approach described in TG-3.8 Combined Presentations provides practical methods for integrating data from multiple accounts to derive MEA indicators.
The UN Statistical Commission has recognised the importance of SEEA for monitoring the Sustainable Development Goals, welcoming the work on interlinkages between SEEA and SDG indicators. Similarly, the monitoring framework for the Kunming-Montreal Global Biodiversity Framework draws directly on SEEA EA for several headline indicators, including those under Goals A and B.
The SEEA EA provides two general advantages for MEA monitoring:
Ocean account-derived MEA indicators support specific policy and management decisions across multiple governance levels:
National policy planning: Governments use MEA indicators to assess progress toward international commitments and to identify priority areas for policy intervention. SDG 14.5.1 (marine protected area coverage) informs national spatial planning decisions, whilst SDG 14.4.1 (fish stocks within sustainable levels) guides fisheries policy reform. The integrated nature of ocean accounts enables assessment of trade-offs between conservation and sustainable use objectives, supporting evidence-based policy design.
International reporting: Multilateral environmental agreements require periodic national reports demonstrating implementation progress. Ocean accounts provide the data foundation for GBF National Reports, Voluntary National Reviews on SDG progress, and UNFCCC National Communications and Biennial Reports. By deriving multiple indicators from a single accounting framework, countries ensure consistency across reporting obligations and reduce the administrative burden of fragmented reporting systems.
Sub-national management: Regional and local authorities responsible for marine spatial management use MEA indicators to track ecosystem condition and management effectiveness within their jurisdictions. Protected area managers assess condition indicators to evaluate whether conservation measures are achieving desired outcomes, whilst coastal development authorities use pollution indicators to monitor land-sea interactions.
Private sector disclosure: The Taskforce on Nature-related Financial Disclosures (TNFD) framework, aligned with GBF Target 15, encourages businesses to assess and disclose nature-related dependencies, impacts, risks and opportunities. Ocean accounts provide standardised metrics that companies operating in marine sectors can use for TNFD-aligned disclosure, connecting corporate sustainability reporting with national environmental accounting. Practical application at project or operational scale requires spatial disaggregation of national-scale account data. Section 3.3 (Target 15) discusses the scale mismatch further.
Investment screening (medium-term aspiration): Development finance institutions and private investors increasingly use environmental indicators for investment screening and portfolio risk assessment. MEA indicators derived from ocean accounts can in principle provide decision-useful information on ecosystem condition trends, regulatory risks associated with environmental degradation, and opportunities in nature-positive sectors such as sustainable aquaculture and marine renewable energy. Operationalising this use case is, however, contingent on the development of open data infrastructure that connects NSO-published accounts to DFI and investor workflows. This requires dissemination in machine-readable formats (e.g., SDMX for environmental statistics, open government data portals) and alignment with emerging market data exchange standards such as those being developed by TNFD. The GOAP data standards initiative provides the appropriate forum for advancing this infrastructure. Until it matures, the investment screening use case should be treated as a medium-term aspiration rather than an operational service from current national ocean accounts.
Sustainable Development Goal 14 aims to “Conserve and sustainably use the oceans, seas and marine resources for sustainable development”. It comprises ten targets addressing marine pollution, ecosystem management, ocean acidification, fisheries, marine protected areas, fisheries subsidies, economic benefits for SIDS and LDCs, marine research, small-scale fisheries, and implementation of international ocean law, each with its own official indicators.
Table 1: SDG 14 targets overview. Per-indicator compilation guidance is provided in Section 3.2.
A general note applies throughout this subsection: for indicators with designated UN custodian agencies, the official indicator value submitted to the global SDG database must be compiled in accordance with the custodian methodology. Ocean account-derived values that do not match the custodian formula should be positioned as supplementary national indicators or as inputs to the official compilation process, not as substitutes for the custodian-aligned submission.
Indicator 14.1.1 (Coastal eutrophication and plastic debris): Physical flow accounts for residuals (pollutants) can record nutrient loadings and plastic debris entering marine ecosystems from land-based sources. The SEEA Central Framework physical flow accounts provide the methodology for tracking pollutant flows from economic activities to the environment. For guidance on pollution flow accounting, see TG-2.7 Pollution Flows.
The indicator comprises two components that can be derived from distinct accounting sources. The coastal eutrophication index (CEI) aggregates information on nutrient concentrations (dissolved inorganic nitrogen and phosphorus) and harmful algal bloom occurrences from condition accounts, combined with nutrient loading data from physical flow accounts. The plastic debris density component uses data on plastic accumulation rates from residual flow accounts and marine litter surveys compiled within the condition accounting framework. Both components require spatial disaggregation to the coastal zone, achievable through the spatial classification systems described in TG-0.1 General Introduction.
Indicator 14.2.1 (Ecosystem-based approaches): SDG 14.2.1 (“Number of countries using ecosystem-based approaches to managing marine areas”) is a Tier II policy survey indicator compiled by UNEP, its custodian, through a national survey instrument that asks countries whether they have adopted ecosystem-based approaches to managing marine areas. The indicator value itself is the country’s response to that survey — it is not directly derived from quantitative ecological data. Ocean accounts cannot substitute for the survey response, but ecosystem extent and condition accounts, combined with governance accounts recording marine protected area coverage and management effectiveness, provide supporting evidence that countries can cite when completing the UNEP questionnaire. Relevant account outputs to reference include: documentation of MPA designation and management (governance accounts), condition monitoring programmes within and outside MPAs (condition accounts), and institutional arrangements for marine spatial management. For detailed guidance on governance arrangements in ocean accounts, see TG-3.7 Governance Accounts.
Indicator 14.3.1 (Ocean acidification): Ecosystem condition accounts include chemical state variables such as pH, dissolved oxygen, and carbonate chemistry. Systematic recording of these variables within the condition accounting framework supports trend monitoring for ocean acidification. The official SDG 14.3.1 methodology (Tier II, IOC-UNESCO as custodian) requires data from an agreed suite of representative sampling stations following GOA-ON guidance, and ocean account-derived pH series should be compiled to be consistent with that methodology. For guidance on deriving biophysical indicators from condition accounts, see TG-2.1 Aggregate Biophysical Indicators. Climate-related applications of ocean acidification indicators are addressed in TG-2.8 Climate Indicators Section 3.3.
Indicator 14.4.1 (Fish stocks within sustainable levels): SDG 14.4.1 is a Tier I indicator for which FAO is the designated custodian. The official methodology classifies stocks into categories (underfished, maximally sustainably fished, overfished) using national stock assessment reports, not a direct biomass-to-BMSY ratio extracted from asset accounts. SEEA CF physical asset accounts for aquatic resources record fish stock biomass, natural growth, harvest, and depletion, and these account data provide the physical stock input that feeds national stock assessment models. The BMSY reference points required for stock status classification are produced by those separate stock assessment modelling steps and are not, in themselves, asset account outputs (see general note above on custodian alignment). For detailed guidance on asset accounts including fish stocks, see TG-3.1 Asset Accounts.
Indicator 14.5.1 (Marine protected area coverage): Ecosystem extent accounts classified by protection status can directly provide this indicator. The SEEA EA supports disaggregation of ecosystem extent accounts by a range of spatial classifications, including protected area status. This indicator connects directly to GBF Target 3 (30x30). A single unified accounting approach can therefore serve both reporting obligations.
Indicator 14.7.1 (Sustainable fisheries as proportion of GDP): SDG 14.7.1 is a Tier I indicator for which FAO is the designated custodian. The official custodian methodology uses a composite measure built from sustainability-weighted catch data and value-added information rather than a simple ratio of fisheries value added to GDP extracted from supply-use tables. Monetary flow accounts linking ecosystem services to economic output, combined with supply-use tables for the ocean economy, can provide an important input to the official compilation, but a value derived only from supply-use tables falls under the general note above on custodian alignment. The supply-use methodology in TG-2.5 Ocean Economy Structure provides an input to, not a replacement for, the official indicator.
The Kunming-Montreal Global Biodiversity Framework (GBF), adopted in December 2022 at the fifteenth Conference of the Parties to the Convention on Biological Diversity (COP-15), sets out ambitious goals and targets for halting and reversing biodiversity loss by 2030. The monitoring framework for the GBF, adopted at COP-15 through Decision 15/5, comprises headline indicators, component indicators, and complementary indicators. SEEA is explicitly recognised as the methodological basis for several headline indicators.
GBF Goals A and B are particularly relevant to ocean accounting: Goal A monitors ecosystem integrity and extent (informed by ecosystem extent and condition accounts), and Goal B monitors nature’s contributions to people (informed by ecosystem services flow accounts). GBF-aligned biophysical indicators for ocean ecosystems are defined and compiled following TG-2.1 Aggregate Biophysical Indicators.
Target 2 aims to “Ensure that by 2030 at least 30 per cent of areas of degraded terrestrial, inland water, and marine and coastal ecosystems are under effective restoration”.
The SEEA EA states that “Target 2, which monitors the area of degraded ecosystems under ecosystem restoration, can be informed by indicators deriving from a combination of ecosystem extent accounts and ecosystem condition accounts”.
A practical difficulty for compilers is determining which ecosystem units count as “degraded”: the denominator of the Target 2 headline indicator. The GBF monitoring framework does not specify a single global threshold, and different national choices will produce non-comparable figures. The SEEA Ecosystem Condition Typology (ECT) classes can be used to operationalise this decision. Table 2A gives indicative degradation classifications and ECT class mappings.
Table 2A: Indicative degradation classification using condition index thresholds
The threshold values shown are illustrative. The GBF monitoring framework is still developing methodological guidance for Target 2, and compilers should flag the chosen thresholds, reference condition basis, and ECT mapping as an explicit assumption in compilation metadata. See TG-3.1 Asset Accounts Section 3.4.2 for guidance on ecosystem condition accounting methodology and ECT class definitions.
Target 3 aims to “Ensure and enable that by 2030 at least 30 per cent of terrestrial and inland water areas, and of marine and coastal areas…are effectively conserved and managed”.
For guidance on recording marine protected areas within the ocean accounting framework, see TG-3.7 Governance Accounts. Marine spatial planning processes that allocate ocean space for conservation and sustainable use are addressed in TG-1.3 Marine Spatial Management.
Target 15 calls for action to “Encourage and enable business…to regularly monitor, assess, and transparently disclose their risks, dependencies and impacts on biodiversity”.
The Taskforce on Nature-related Financial Disclosures (TNFD) has developed a framework aligned with Target 15 requirements. The TNFD v1.0 recommendations, released in September 2023, draw on SEEA as a methodological foundation for nature-related metrics, with supplementary sector guidance (including for fishing and marine sectors) published as additional materials through 2024-2025. Ocean accounts can support corporate disclosure by:
Scale mismatch between national accounts and TNFD corporate disclosure. National ocean accounts are typically compiled at ecosystem-type and EEZ/national resolution, whereas TNFD corporate disclosure requires location-specific, asset-level assessment of dependencies and impacts. The two scales are not directly interchangeable. Bridging them requires a spatial disaggregation (or “downscaling”) workflow in which:
The SEEA EA guidance on sub-national accounts (Chapter 4, Section 4.4) provides the methodological basis for this disaggregation. Detailed operational guidance for company-side TNFD compilation is beyond the scope of this Circular and is better addressed in a dedicated applied circular on corporate disclosure. The role of TG-2.10 is to clarify that national ocean accounts do not, on their own, deliver project-scale TNFD outputs.
The Paris Agreement, adopted in 2015, aims to limit global temperature increase to well below 2 degrees Celsius, with efforts to limit to 1.5 degrees Celsius. Countries submit Nationally Determined Contributions (NDCs) outlining their climate commitments, which increasingly include ocean-based mitigation and adaptation measures.
Ocean ecosystems contribute to climate regulation through:
The SEEA EA recognises global climate regulation as an ecosystem service, defined as “the regulation of the chemical composition of the atmosphere and oceans by living organisms and ecosystem processes”. Coastal ecosystems including mangroves, salt marshes, and seagrass meadows are particularly effective at carbon sequestration and storage. These ecosystems are covered in detail in TG-6.2 Mangrove and Coastal Wetland Accounting and TG-6.3 Seagrass Accounts.
Ocean accounts can support UNFCCC/Paris Agreement monitoring through:
Blue carbon accounting: Ecosystem extent accounts for mangroves, salt marshes, and seagrass meadows record the area of these carbon-rich ecosystems. Ecosystem condition accounts can include carbon stock variables (above-ground biomass, soil carbon). Ecosystem services flow accounts can record annual carbon sequestration rates, . For guidance on climate-related indicators from ocean accounts, see TG-2.8 Climate Indicators.
LULUCF reporting alignment: Ecosystem extent accounts recording conversions between ecosystem types can be aligned with LULUCF activity data requirements. This is particularly relevant for coastal wetland conversions (mangrove deforestation, wetland drainage), which are major sources of emissions.
The IPCC 2013 Wetlands Supplement requires activity data structured by specific coastal wetland categories with sub-classifications by land-use change type (conversions to and from each wetland category, plus rewetting and drainage). SEEA ecosystem extent accounts are typically classified using the IUCN Global Ecosystem Typology (GET), which does not map one-to-one to the IPCC categories. To produce GHG inventory-ready data from SEEA extent accounts, compilers need a crosswalk that identifies (a) which SEEA/IUCN-GET ecosystem types correspond to each IPCC coastal wetland category and (b) where additional conversion factors, splits, or expert judgment are required.
Table 2B: Indicative crosswalk — IUCN GET coastal wetland types to IPCC Wetlands Supplement activity data categories
This crosswalk is illustrative and should be adapted to national IUCN GET classification choices. Where SEEA extent data directly populate inventory activity data, the workflow is straightforward. Where conversion factors or splits are needed, compilers should document the assumptions and, where possible, use country-specific emission factors developed in coordination with the national greenhouse gas inventory team. For deeper guidance on the relevant blue carbon ecosystems and their accounting, see TG-6.2 Mangrove and Coastal Wetland Accounting and TG-6.3 Seagrass Accounts.
Adaptation indicators: Ocean accounts can support monitoring of ecosystem-based adaptation by tracking:
For guidance on disaster risk indicators derived from ocean accounts, see TG-2.9 Disaster Risk and Resilience. The linkage between ecosystem extent, condition, and coastal protection services provides a quantitative basis for valuing ecosystem-based adaptation investments.
The Agreement on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ Agreement) was adopted in June 2023 and entered into force on 17 January 2026, 120 days after the sixtieth ratification on 19 September 2025. The agreement establishes a legal framework for marine biodiversity in areas beyond national jurisdiction (ABNJ), including the high seas and the seabed beyond the continental shelf. The first Conference of the Parties is expected in 2026, at which detailed monitoring and reporting requirements will begin to be elaborated.
This section is presented as forward-looking horizon scanning rather than current operational guidance. No country currently has operational ocean accounts that extend into ABNJ, and the practical compilation of such accounts will require institutional and data-sharing arrangements that do not yet exist. The material below sets out (i) the relevant elements of the BBNJ Agreement, (ii) where ocean accounting concepts may eventually contribute, and (iii) the prerequisites that national statistics offices and partner institutions would need to address before ABNJ accounting becomes feasible.
The BBNJ Agreement addresses four main elements:
While the detailed monitoring framework for the BBNJ Agreement is still being developed through the Conference of the Parties process, ocean accounts can in principle contribute to:
Marine genetic resources: Physical flow accounts can record the extraction and use of marine genetic resources from ABNJ, including their incorporation into biotechnology and pharmaceutical products. Monetary flow accounts can track benefit-sharing arrangements. The SEEA EA ecosystem services classification includes genetic material provisioning, which provides a methodological basis for this emerging requirement.
Area-based management in ABNJ: Ecosystem extent accounts can be extended to cover ecosystem types in ABNJ, including deep-sea ecosystems such as abyssal plains, hydrothermal vents, and seamounts. The IUCN Global Ecosystem Typology provides classifications for deep-sea ecosystem functional groups that can support extent accounting. For guidance on deep-sea ecosystem accounting, see TG-6.6 Deep Sea and ABNJ Accounts.
Environmental impact assessment: The ecosystem condition and services accounting framework provides a structured approach to baseline assessment and impact monitoring that can inform environmental impact assessments in ABNJ. Condition reference levels can be established for minimally impacted deep-sea ecosystems against which project impacts can be assessed.
The SEEA EA acknowledges challenges for accounting in ABNJ, noting that for marine ecosystems “beyond the continental shelf…accounting may be challenging due to limited data availability and complex jurisdictional arrangements”.
Before national statistics offices can compile ocean accounts that extend meaningfully into ABNJ, several prerequisite arrangements need to be in place:
Until these prerequisites are in place, BBNJ-related ocean accounts should be treated as a development priority rather than a near-term reporting product. The accounting framework provides a methodological foundation that can be applied as data and governance arrangements develop.
This section presents a synthetic worked example demonstrating how MEA indicators are derived from ocean account data through a step-by-step compilation procedure. The example focuses on a subset of indicators to illustrate the accounting-to-indicator workflow.
Setting: Hypothetical Coastal State (Country A) with an Exclusive Economic Zone (EEZ) of 250,000 km², including 5,000 km² of coral reef ecosystems and 12,000 km² of seagrass meadows. Country A has compiled ocean accounts for the 2024 reporting year and seeks to derive indicators for SDG 14.5.1 (MPA coverage), GBF Target 3 (protected area effectiveness), and SDG 14.3.1 (ocean acidification).
Accounting period: Calendar year 2024 (opening stock 1 January 2024, closing stock 31 December 2024).
Data sources: Ecosystem extent accounts from remote sensing analysis, ecosystem condition accounts from marine monitoring network, governance accounts from national MPA authority.
The first step involves compiling ecosystem extent accounts classified by IUCN protection category. Country A’s extent account for coral reefs, disaggregated by protection status, appears as follows:
Table 2: Ecosystem extent account for coral reefs by protection status (km²)
The extent account structure follows SEEA EA Table 4.1, with spatial classification disaggregated by IUCN protected area category as recommended in SEEA EA para 4.19. The “additions” and “reductions” rows record changes in protection status during the accounting period. In this example, Country A designated 150 km² of previously unprotected coral reef as protected areas during 2024 (50 km² as strict protection, 100 km² as multiple use).
SDG indicator 14.5.1 measures “Coverage of protected areas in relation to marine areas”. The indicator is calculated as the ratio of protected area to total area:
Formula:
SDG 14.5.1 = (Total protected area / Total marine area) x 100
Calculation for Country A (coral reefs only):
Protected coral reef area = 450 + 900 + 600 = 1,950 km² Total coral reef area = 5,000 km² Coverage = (1,950 / 5,000) x 100 = 39.0%
This is a coral-reef-subset diagnostic measure, not the value submitted as the national SDG 14.5.1 figure, which is computed at the whole-EEZ level (see Step 2a).
To produce the EEZ-level SDG 14.5.1 value, Country A consolidates its ecosystem extent accounts for all ecosystem types in the EEZ into a single multi-ecosystem extent account classified by protection status. This consolidation step follows the multi-ecosystem extent account template described in TG-3.1 Asset Accounts Section 3.4.2 and the spatial classification guidance in SEEA EA Chapter 4.
Table 2B-Step2a: Consolidated EEZ-level extent account by protection status (km², closing extent 31 Dec 2024)
The seagrass and other-ecosystem rows are produced from companion extent accounts compiled using the same protection-status classification used for coral reefs in Step 1. With the consolidated account in place, the EEZ-level SDG 14.5.1 value is:
Total protected marine area = 1,950 + 4,800 + 80,000 = 86,750 km² Total EEZ area = 250,000 km² Coverage = (86,750 / 250,000) x 100 = 34.7%
The EEZ aggregate (34.7%) exceeds both the SDG 14.5 target of 10% and the GBF Target 3 goal of 30%. The coral-subset value (39.0%) and the EEZ-aggregate value (34.7%) measure different things on different denominators (5,000 km² coral reef versus 250,000 km² EEZ). Only the EEZ aggregate is comparable with the official SDG 14.5.1 submission requirement, whilst the coral subset is a diagnostic tool for identifying within-EEZ protection gaps.
To assess management effectiveness for GBF Target 3, Country A compiles ecosystem condition indicators for coral reefs, comparing protected and unprotected areas. The condition account records normalised indicators (scale 0-1) for key condition variables:
Table 3: Ecosystem condition indicators for coral reefs by protection status (index 0-1)
The aggregate condition index uses an unweighted arithmetic mean of the four normalised indicators. This is a methodological choice with material consequences: arithmetic averaging implicitly assigns equal importance to each variable, treats them as substitutable, and can mask threshold breaches in any single variable (a low coral cover score may be offset by a high water quality score). Alternative aggregation methods — geometric mean (which penalises low scores more strongly), weighted arithmetic mean (which allows policy or ecological weighting), or minimum-value rules (which surface threshold breaches) — are discussed in TG-2.1 Aggregate Biophysical Indicators Section 3.6 and in the OECD Handbook on Constructing Composite Indicators (2008). Country A should document the chosen aggregation rule, the weighting (here, equal), and the reference condition basis as part of the metadata accompanying any cross-country comparison.
Sensitivity check (geometric mean): Applying a geometric mean to the four normalised indicators for the IUCN I-II column yields:
Geometric mean = (0.85 x 0.80 x 0.88 x 0.82)^(1/4) = (0.49069)^(0.25) ≈ 0.836
The geometric-mean condition index for IUCN I-II is 0.836 compared with the arithmetic-mean value of 0.84, close in this case because the four variables span a narrow range. The two aggregation rules would diverge more substantially in ecosystems where one variable is markedly lower than the others. This is exactly the case in which the choice of aggregation rule begins to affect policy interpretation. Countries comparing effectiveness scores across ecosystems or jurisdictions should therefore report the aggregation rule explicitly.
The reference column is 1.00 by construction. The reference condition for healthy coral reefs (based on historical data and marine reserve benchmarks, following the reference condition methodology described in TG-2.1 Aggregate Biophysical Indicators Section 3.4.2) is already applied when each variable is normalised, so a normalised indicator of 1 is the reference and the reference is not applied a second time.
GBF Target 3 requires not only coverage but “effective” conservation. The CBD monitoring framework adopted in Decision 15/5 addresses effectiveness through a suite of headline, component, and complementary indicators drawing on the Management Effectiveness Tracking Tool (METT), the World Database on Protected Areas (WDPA), and IUCN Green List criteria, rather than through any single ratio of condition indices. The metric computed below is therefore presented as a nationally-derived analytical metric for management assessment, not as the official GBF Target 3 effectiveness indicator submitted under the CBD monitoring framework.
Official GBF Target 3 effectiveness reporting should follow the METT-based and IUCN Green List approaches recognised in the CBD monitoring framework. The account-derived condition ratio described here complements, but does not replace, those assessments.
Formula (nationally-derived analytical metric):
Nationally-derived effectiveness = (Protected area condition index / Reference condition index) x 100
Calculation for Country A:
IUCN I-II = (0.84 / 1.00) x 100 = 84.0% IUCN III-IV = (0.71 / 1.00) x 100 = 71.0% IUCN V-VI = (0.65 / 1.00) x 100 = 65.0% Not protected = (0.49 / 1.00) x 100 = 49.0%
Area-weighted average across all protected coral reefs:
Weighted = [(450 x 0.840) + (900 x 0.710) + (600 x 0.650)] / 1,950 = [378.0 + 639.0 + 390.0] / 1,950 = 1,407.0 / 1,950 = 72.2%
The area-weighted figure indicates that whilst 39% of coral reefs are protected, those protected areas achieve on average 72% of reference condition, a useful internal management signal. The differential across IUCN categories (84% for strict protection, 65% for sustainable use) informs management strategy. For external reporting against GBF Target 3, however, this figure should be transmitted as supplementary national analysis alongside the METT/Green List-based information that the CBD monitoring framework expects.
For SDG indicator 14.3.1 (average marine acidity), Country A compiles pH measurements from its marine monitoring network. SDG 14.3.1 is a Tier II indicator under IOC-UNESCO custodianship and relies on data from an “agreed suite of representative sampling stations.” The Global Ocean Acidification Observing Network (GOA-ON) provides the internationally recognised methodology for station design and data reporting against this indicator. Country A’s station network is therefore designed to satisfy GOA-ON minimum design criteria:
Qualification for countries with sparse networks. Countries that cannot currently meet GOA-ON station-density criteria can, as an interim measure, (i) participate in regional data-sharing arrangements (e.g., regional ocean acidification hubs) to pool station coverage, (ii) use spatial interpolation of available station data combined with remote-sensing-derived sea-surface temperature and salinity to estimate carbonate chemistry, or (iii) report the SDG 14.3.1 value with explicit metadata flags noting the network limitations. These interim approaches should be documented clearly so that data users understand the basis of the reported value.
The condition variable account records pH at 12 representative sampling stations across the EEZ:
Table 4: Ocean pH measurements by station (2024 annual mean)
The uniform 0.07-unit change shown across all stations is a stylised feature of this worked example. In a real GOA-ON-aligned network, spatial heterogeneity in pH change between zones would be expected and is itself diagnostically useful.
SDG indicator 14.3.1 measures “Average marine acidity (pH) measured at agreed suite of representative sampling stations”. The indicator is the arithmetic mean pH across all monitoring stations (computed in a manner consistent with the GOA-ON / IOC-UNESCO methodology referenced in Step 5):
Calculation:
SDG 14.3.1 = Sum of pH values / Number of stations = (8.05 + 8.03 + 8.07 + 8.06 + 8.08 + 8.09 + 8.08 + 8.10 + 8.11 + 8.10 + 8.12 + 8.13) / 12 = 97.02 / 12 = 8.085
The 2024 mean pH of 8.085 represents a decline of 0.07 pH units relative to the 2015 baseline of 8.155, indicating a systematic acidification trend affecting the entire EEZ.
The final step integrates the three derived indicators in a combined presentation that supports cross-MEA analysis:
Table 5: Country A MEA indicator summary (2024)
Interpretive note on spatial scope. Ecosystem-subset indicators (the coral-only MPA coverage figure) are diagnostic tools for identifying protection gaps within a specific ecosystem, whilst the whole-EEZ aggregate is the value comparable with the official SDG 14.5.1 submission requirement. National dashboards drawing on this table should always label the spatial scope of each indicator explicitly.
This combined presentation enables integrated analysis. Country A has met quantitative protection targets for both SDG 14.5 and GBF Target 3 at the EEZ level, but ecosystem-level analysis reveals that coral reef protection, whilst above 30%, still leaves 61% of reefs unprotected. The nationally-derived effectiveness metric of 72% suggests room for improvement in MPA management, to be reported as supporting information alongside METT or IUCN Green List assessments rather than as the official GBF Target 3 effectiveness value. Ocean acidification trends indicate a systematic pressure affecting all marine ecosystems regardless of protection status. Addressing that pressure requires climate mitigation action of the kind addressed through UNFCCC/Paris Agreement commitments.
For a structured cross-walk between MEA reporting frameworks and ocean account types, see the relevant subsection: Section 3.2 (SDG 14), Section 3.3 (GBF), Section 3.4 (Paris Agreement/NDCs), Section 3.5 (BBNJ).
Reporting frequency harmonisation. Different MEAs operate on different reporting cycles. SDG Voluntary National Reviews are typically annual or biennial, GBF national reporting is biennial, and NDC updates follow a five-year ratchet with biennial transparency reporting. Where annual compilation is not feasible, mid-cycle GBF indicators should use the most recently compiled account year, and the reference year of the underlying account data should be documented explicitly in the national metadata submitted with each report.
Authors: [To be confirmed]
Reviewers: [To be confirmed]
Cite this report
Multilateral Environmental Agreement Indicators (2026) (GOAP Technical Guidance on Ocean Accounting, TG-2.10, v0.7.3). GOAP Secretariat. https://guidance.oceanaccounts.org/circulars/section-2/2-10-mea-indicators/
guidance.oceanaccounts.org/circulars/section-2/2-10-mea-indicators
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