Global Ocean Accounts Partnership Secretariat · GOAP Technical Guidance on Ocean Accounting · circular
This Circular provides guidance on compiling indicators of environmental goods and services, including ecosystem services, within the context of ocean accounting. Ecosystem services represent the contributions that marine and coastal ecosystems make to benefits enjoyed by people and the economy. These contributions fall into three categories: provisioning services such as fish and other harvested biomass, regulating services such as coastal protection and carbon sequestration, and cultural services such as recreation and amenity values.
This Circular establishes an indicator framework aligned with the SEEA Ecosystem Accounting (SEEA EA) reference list of ecosystem services, providing guidance on measurement approaches for provisioning, regulating, and cultural service indicators in both physical and monetary terms. The guidance covers the derivation of indicators from ecosystem service flow accounts, the selection of appropriate measurement units, and the interpretation of physical versus monetary indicators for different policy applications.
Section 3.10 is normative for the publication on monetary valuation method. It sets out the value concepts the accounts use, the SEEA EA five-level preference order, the methods at each level, the methods that are not admissible as account entries, and a worked application across four marine ecosystem services. Compilers valuing any ecosystem service, in any circular, apply that section. Whether and when to value at all, and how the resulting figures should be communicated and caveated, remain with TG-1.9 Safe Usage of Monetary Valuation, which should be read first; asset-level net present value is in TG-3.1 Asset Accounts Sections 3.3 and 3.5.3.
The methodology supports ocean-related EGSS measurement (identifying industries engaged in environmental protection and resource management under CEPA and CReMA), green and blue economy monitoring, environmental protection expenditure tracking, and marine spatial planning by quantifying ecosystem service flows associated with different ocean uses (see TG-1.2 Marine Spatial Planning).
This Circular is distinct from TG-3.2 Flows from Environment to Economy, which covers the underlying supply and use table methodology for ecosystem service accounts. The present Circular focuses on compiling summary indicators from those accounts. It builds on the asset-service linkages established in TG-3.1 Asset Accounts.
This Circular requires familiarity with:
For the monetary valuation methods referenced throughout this Circular, see Section 3.10 below and TG-1.9 Safe Usage of Monetary Valuation.
Indicators derived from ecosystem service accounts provide summary measures that can be used to track changes over time, compare across ecosystem types and regions, and inform policy decisions concerning ocean management and conservation.
This section establishes the indicator framework (Section 3.1), addresses the relationship between ecosystem services and the environmental goods and services sector (Section 3.2), then examines indicators for each major category of ecosystem services: provisioning (Section 3.3), regulating (Section 3.4), and cultural services (Section 3.5). Section 3.6 addresses the distinction between physical and monetary indicators and their appropriate applications. Section 3.7 presents the compilation procedure for deriving indicators from accounts, and Section 3.8 provides a worked example with synthetic data.
The SEEA EA provides a framework for deriving indicators from ecosystem service accounts. Ecosystem service indicators can be derived from both the supply and use perspectives of the ecosystem services supply and use tables (SUTs), and can be expressed in physical or monetary terms. Figure 2.4.1 illustrates how ecosystem assets supply the three service categories, how those flows are recorded in the supply and use tables, and how physical indicators — with an optional valuation step — are derived from them.
· Figure 2.4.1
Source TG-2.4 draft v7, §3.1 (indicator typology), §3.6 (physical vs monetary), §3.7 Steps 5--7 (compilation sequence); SEEA EA Tables 5.3--5.4 (supply-use of ecosystem services), Chapter 6 & para. 9.18 (monetary aggregates).
The reference list of ecosystem services in SEEA EA organises services into three broad categories, summarised in Table 3.1.1 below.
For ocean accounting, each category encompasses distinct marine ecosystem services with specific measurement requirements and indicator possibilities. Table 1 summarises the key marine ecosystem services within each category and their indicative measurement units. The selection in Table 1 reflects the ecosystem services most commonly relevant to marine and coastal contexts and is not exhaustive. The SEEA EA reference list (Table 6.3) includes additional services such as wild animals and plants provisioning (covering non-fish marine species and marine bioprospecting for genetic material), storm mitigation services (where these are analytically distinct from coastal protection), and soil and sediment retention services. Compilers should consult the full SEEA EA reference list and include additional services where they are material for their national ocean accounting context.
Table 1: Marine ecosystem services indicator framework (adapted from SEEA EA Table 6.3)
Three main types of indicators can be derived from ecosystem service accounts:
Flow indicators measure the quantity of ecosystem services supplied or used during an accounting period. These are the primary indicators derived from ecosystem service SUTs and represent the most direct measure of ecosystem contributions to benefits. Examples include tonnes of fish harvested (provisioning), tonnes of carbon sequestered (regulating), and visitor-days (cultural services).
Capacity indicators measure the potential or sustainable level of ecosystem service supply. The SEEA EA defines ecosystem capacity as “the ability of an ecosystem to generate an ecosystem service under current ecosystem condition, management and uses, at the highest yield or use level that does not negatively affect the future supply of the same or other ecosystem services.” Capacity indicators are particularly important for sustainability assessment, as they allow comparison of actual flows against sustainable thresholds. The relationship between ecosystem condition and service capacity is addressed in TG-3.1 Asset Accounts.
Compiling capacity indicators when formal assessments are unavailable Formal capacity assessments are available for some marine ecosystem services (notably fisheries stock assessments), but for most regulating and cultural services there is no equivalent assessment in most developing-country contexts. Compilers should adopt a tiered approach:
Document the proxy method and benchmark assumptions transparently.
Sustainability ratios (actual flow / capacity) should only be computed for Tier 1 and Tier 2 entries, with the tier explicitly disclosed in metadata.
Derived indicators combine ecosystem service data with other information to produce policy-relevant ratios and indices. Examples include ecosystem service intensity indicators (ecosystem services per hectare or per unit of ecosystem asset value), sustainability ratios (actual flow divided by sustainable capacity), and dependency ratios (share of industry output dependent on ecosystem services).
For practical compilation purposes, compilers may find it useful to distinguish headline indicators from supporting indicators. Headline indicators are a small number of high-level summary measures intended for national reporting and policy communication—for example, Gross Ecosystem Product, total fish provisioning services, and aggregate coastal protection value. Supporting indicators provide the disaggregated detail needed for analytical work and are typically reported in supplementary tables. The SEEA EA notes that headline indicators “provide a summary of key features of ecosystems that can be monitored over time” whilst detailed indicators “provide more comprehensive information for use by researchers and policy analysts.”
Many ecosystem services, particularly regulating services, are generated at landscape or seascape scale involving multiple ecosystem types. For indicator purposes, allocation of service flows to specific ecosystem types may be required. The SEEA EA notes that “a number of ecosystem services, particularly regulating and maintenance services but also some cultural services, are generated at landscape scale in the sense that this involves a range of ecosystem assets of different types.”
For ocean accounting, spatial allocation is particularly relevant for:
The Environmental Goods and Services Sector (EGSS) framework complements the ecosystem services accounting framework by identifying the industries and activities engaged in producing goods and services for environmental protection and resource management purposes. Whilst ecosystem services flow from ecosystems to economic units, EGSS represents the economic response—the industries and activities that produce goods and services aimed at environmental protection (following CEPA) or resource management (following CReMA).
The SEEA Central Framework describes EGSS as comprising “the producers of environmental protection and resource management goods and services” and notes that “the output of the EGSS equals the sum of the supply of environmental protection services and resource management services.” For ocean accounting, the relevant EGSS activities include:
Table 2: Ocean-related EGSS activities and their connections to ecosystem services
EGSS output represents economic expenditure on activities that maintain, enhance, or restore the capacity of ecosystems to supply services. For example, expenditure on marine protected area management (CEPA 6) maintains ecosystem condition that sustains the capacity of coral reef, mangrove, and seagrass ecosystems to supply services. Fisheries management expenditure (classified under CEPA 6) aims to maintain fish stocks within sustainable limits, thereby protecting ongoing provisioning capacity.
EGSS indicators are derived from supply-use tables extended to incorporate environmental protection and resource management activities. The SEEA CF describes the compilation approach as involving three steps: (i) identifying relevant industries and activities using CEPA and CReMA classifications, (ii) measuring the output of environmental goods and services by those industries, and (iii) measuring the use of those goods and services by final demand categories and intermediate consumption.
For ocean accounting, key data sources include:
Compilers should distinguish between the producer types summarised in Table 3.2.2 below.
The distinction matters for indicator interpretation: primary and secondary producers contribute to measured EGSS output and value added, whilst ancillary production is not separately recorded as EGSS output — it is embedded in the intermediate consumption of the producing industry, following SEEA CF paras. 4.100—4.105.
Ecosystem service categories and the mapping of marine services to the SEEA EA Table 6.3 framework are described in TG-3.2 Flows from Environment to Economy Section 3.1. The sections below present the indicator derivation procedure for each service category applicable to ocean accounting.
Fish provisioning services represent the ecosystem contributions to the growth of wild fish and other aquatic organisms that are harvested by capture fisheries. Key indicators include:
Physical flow indicators:
Capacity and sustainability indicators:
Fish provisioning services and asset accounts are tightly coupled: extraction recorded in the ecosystem service SUT should correspond to extraction entries in the aquatic resource asset account as described in TG-3.1 Asset Accounts. This correspondence provides a consistency check for ocean accounts.
IUU fishing must be included in provisioning service flow estimates where estimable, because omission overstates sustainability. For the SEEA CF accounting treatment and estimation methods, see TG-4.10 Extending Fisheries Statistics Section 3.8.4.
While provisioning of water from marine sources is typically treated as an abiotic flow rather than an ecosystem service, ecosystem contributions to water quality and regulation may be relevant:
Water-related indicators:
Other biomass provisioning indicators:
Decision rule: Intermediate vs final ecosystem services for regulating services used by industries SEEA EA paras. 6.11—6.17 distinguish intermediate ecosystem services (services supplied by one ecosystem to another ecosystem, supporting the supply of a further final service) from final ecosystem services (services flowing directly to economic units as beneficiaries). For regulating services consumed by industries (e.g., water purification benefiting an aquaculture operation, coastal protection benefiting tourism infrastructure), the SEEA EA convention is to record them as final services flowing to the industry as beneficiary, not as intermediate inputs to the industry’s production process. The industry appears as a user column in the ecosystem service use table. Intermediate ecosystem service flows are recorded separately (e.g., in supplementary tables) when the analytical purpose requires tracing the ecosystem-to-ecosystem contributions that support a final service. Compilers should not collapse intermediate and final flows into a single column without indicating which row represents which type, as this conflates analytically distinct relationships and risks double-counting.
Global climate regulation services represent ecosystem contributions to reducing concentrations of greenhouse gases in the atmosphere through carbon sequestration and storage. Marine ecosystems form part of the global carbon cycle, and “blue carbon” ecosystems such as mangroves, seagrass meadows, and salt marshes are recognised for their climate mitigation potential.
The SEEA EA identifies two components of global climate regulation services:
Carbon retention reflects the ability of ecosystems to accumulate and retain carbon stocks, supplying a service through the avoided emission of carbon to the atmosphere. The indicator for carbon retention is the stock of carbon held by ecosystem assets at the beginning of the accounting period. Operationally:
Carbon Retention Service Flow (period t) = Opening carbon stock (asset account, period t)
This identity links the service supply directly to the opening balance of the carbon component of the relevant ecosystem asset account in TG-3.1 Asset Accounts. Compilers should record carbon retention service supply values that equal the corresponding opening stock values in the asset account, providing an automatic consistency check. Where formal asset accounts are not yet compiled, the opening stock can be derived from the most recent national blue carbon inventory or default IPCC Wetlands Supplement (2014) values, with documentation of the source.
Compilers should distinguish between soil organic carbon (slow-cycling, long-residence-time stock dominant in mangrove and seagrass sediments and most relevant to carbon retention indicators) and above-ground biomass carbon (faster-cycling, more dynamic, more relevant to short-period sequestration flux estimates). The two pools have different measurement methods and uncertainty profiles, and disaggregation supports interpretation of the retention versus sequestration distinction.
Carbon sequestration reflects the ability of ecosystems to remove carbon from the atmosphere for long-term storage. The indicator is net carbon uptake over the accounting period, typically measured as net ecosystem carbon balance.
Key indicators:
For blue carbon ecosystems, the SEEA EA recommends that measurement scope include carbon stored to a maximum of two metres below the surface in the case of organic carbon-rich soils such as those found in mangroves and seagrass meadows. Related asset information is recorded in TG-3.1 Asset Accounts.
The treatment of global climate regulation services raises questions about user attribution. The SEEA EA notes that the user of global climate regulation services is “the global community or, where the focus is on a national ecosystem accounting area, the rest of the world.” For national ocean accounts, this implies that the bulk of carbon sequestration services should be attributed to the rest of the world as the beneficiary. This attribution reflects the global public good nature of climate regulation, whilst a country may also derive domestic benefits from its own contribution to global climate stability. In practice, compilers should record the full physical flow of carbon sequestration in the supply table (attributed to domestic ecosystem types) and allocate the use to “rest of the world” in the use table.
For monetary valuation, the exchange value approach would value the service at the price that would be agreed between a willing buyer and seller, which in practice is typically approximated using observed carbon market prices or abatement cost methods. The indicator implications are that physical indicators of carbon sequestration represent domestic ecosystem contributions, whilst monetary indicators should be interpreted carefully given that the beneficiaries are predominantly global rather than domestic.
For the full biophysical basis of coastal protection services, SPA/SBA delineation, and tiered method selection, see TG-3.2 Flows from Environment to Economy Section 3.3.,
Operational definition: “kilometres of coastline protected” “Kilometres of coastline protected” is defined as the length of beneficiary shoreline landward of protective ecosystems with population or assets at risk under a defined reference hazard scenario, following SEEA EA para. 9.72 (no flow recorded where there are no potential damages to avoid). Compilers must:
2018 for coral reefs).
SEEA EA does not prescribe a single numeric attenuation threshold or return period for coastal protection service measurement. Both are localisation decisions to be made by the compiling agency drawing on national coastal risk assessment standards. Cross-country comparability requires that the chosen return period and attenuation threshold are disclosed in compilation metadata and held constant across reporting periods. Cross-references: TG-6.1 Coral Reef Accounts, TG-6.2 Mangrove and Coastal Wetland Accounting.
Physical indicators:
Capacity indicators:
The measurement of coastal protection services depends on the likelihood of hazard events and the presence of assets or population at risk. Even where hazard probability is high, no ecosystem service flow is recorded if there are no potential damages to be avoided.
Water purification indicators:
Nursery and habitat maintenance indicators:
The SEEA EA treats nursery services as potentially intermediate services: “the nursery population services supplied by seagrass meadows are an input to the supply of fish biomass provisioning services, which in turn contribute to the benefit of marketed fish.” Recording both final and intermediate ecosystem services is therefore necessary to fully capture the contributions of coastal ecosystems to commercial fisheries.
Erosion control indicators:
Recreation-related services are the ecosystem contributions to recreational activities through the biophysical characteristics and qualities of ecosystems that enable people to use and enjoy the marine environment.
Physical indicators:
Activity-specific indicators:
Decision rule: Recording recreational catch in supply and use tables Where recreational catch is material (as a rule of thumb, where it represents 5% or more of commercial catch by weight, or where it is policy-relevant regardless of share), compilers should record it as a dedicated row in the physical supply and use tables for fish provisioning, with users allocated to “Households” (subsistence/recreational consumption) or “Tourism” (where the catch supports a tourism enterprise). The recreation cultural service is recorded separately on its visitor-day row. The two rows capture distinct phenomena — biomass extracted vs. experiential service — and must not be aggregated into a single headline “fish provisioning” figure without disclosure. Where recreational catch is not material and is omitted from the supply table, compilers should add a footnote to the provisioning row explicitly stating the omission and the rationale.
In practice, the physical indicator for the cultural service should be expressed in units that capture the recreational experience (visitor-days or trips), whilst the physical indicator for the provisioning service should be expressed in harvest units (tonnes). Monetary indicators require particular attention: the cultural service value (willingness to pay for the recreational experience) and the provisioning service value (resource rent on the harvested biomass) capture distinct economic contributions and should be presented separately rather than summed without explanation.
Visual amenity services represent ecosystem contributions to local living conditions through sensory benefits, especially visual appreciation of seascapes.
Physical indicators:
Monetary indicators (see Section 3.6.2):
Scientific and educational indicators:
Spiritual and symbolic indicators:
Indigenous and local communities often hold deep cultural and spiritual connections to marine ecosystems that conventional indicators may not adequately capture. The governing principle is that measurement of these values rests on the free, prior, and informed consent (FPIC) of the communities concerned: indicators are co-designed with those communities, complex cultural relationships are not reduced to simplistic quantitative measures, and qualitative supplementary information accompanies any quantitative figures. Where traditional ecological knowledge contributes to the understanding of ecosystem condition or service flows, compilers should acknowledge and appropriately attribute it.
The trade-offs between physical and monetary ecosystem service indicators — including advantages, limitations, and appropriate applications — are analysed in TG-1.9 Safe Usage of Monetary Valuation, which should be read in conjunction with this circular. The methods themselves, and the preference order governing their selection, are set out in Section 3.10 below. Physical accounts should always be compiled as the primary output, with monetary valuation undertaken as a complement where appropriate and feasible.
Valuation approach selection by service type follows the criteria in Table 1. For global climate regulation services, the preferred valuation approach uses observed carbon market prices or abatement cost methods, which align with the exchange value concept used in national accounts. The “social cost of carbon” (SCC) estimates the marginal damage from an additional tonne of carbon emissions. It represents a welfare-based measure rather than an exchange value and is therefore not the preferred approach under SEEA EA guidance. Where carbon market prices are unavailable, or where the policy context specifically requires a damage-cost perspective, the SCC may be used as an alternative. Where the SCC is used, compilers should clearly document that it represents a welfare value rather than an exchange value and note the divergence from standard accounting practice.
When presenting ecosystem service indicators, compilers should follow the principles set out in Table 3.6.4 below.
Identify which ecosystem services are most relevant to the national or subnational ocean accounting area, and which economic units and communities use those services. This step should involve:
For ocean accounting, priority services typically include fish provisioning (used by fisheries industries), coastal protection (used by coastal property owners and government), carbon sequestration (used by the global community), and recreation (used by households).
Primary data sources include:
Data quality should be assessed following TG-0.7 Quality Assurance, with particular attention to temporal consistency and spatial coverage.
The supply and use tables are the input to every indicator below, and their compilation is specified in TG-3.2 Flows from Environment to Economy Section 3.3 — the structure of PSUTs, the procedure, the supply and use sub-procedures, physical units, the supply = use identity, and the treatment of beneficiaries who fall outside survey frames. It is not restated here.
Two properties of the compiled tables determine what the indicators in Step 5 can carry, and are worth confirming before proceeding:
From the compiled supply and use tables, derive flow indicators for reporting and analysis:
Where monetary indicators are required, apply valuation methods following the preference order in Section 3.10.2 below:
For each valuation, document the method, data sources, key assumptions, and uncertainty.
From the monetary valuations, derive aggregate indicators:
The example uses synthetic data for three marine ecosystem types (mangroves, seagrass meadows, and coral reefs) to illustrate the compilation procedure described in Section 3.7. The supply = use identity (total supply in Table 4 equals total use in Table 5 for each service row) is verified at Step 4 below. Compilers revising either table independently must re-verify this identity.
The accounting area is a coastal province encompassing 500 km² of mangrove forest, 200 km² of seagrass meadows, and 150 km² of coral reef systems. The area supports commercial fisheries, coastal aquaculture, and marine tourism. The accounting period is calendar year 2025.
Through consultation with the provincial environment ministry and fisheries agency, five priority ecosystem services were identified:
The tables below are the input to this example, compiled under TG-3.2 Flows from Environment to Economy Section 3.3 from field surveys, remote sensing, modelling, fisheries registration data, the property cadastre and tourism statistics. They are reproduced here because the indicator arithmetic that follows cannot be checked without them, not to restate how they were built.
Table 4: Physical ecosystem service supply by ecosystem type, 2025. Supply totals in this table must equal use totals in Table 5 for each row; the identity is verified at Step 4.
Reading the supply table: coral reefs dominate commercial fish provisioning (1,500 t, 43%) and recreation (45,000 visitor-days, 87%); mangroves dominate carbon sequestration (4,000 tC/yr, ~70%) and coastal protection (45 km, 45%). These shares drive the disaggregated indicators at Step 5.
Table 5: Physical ecosystem service use by sector, 2025. Supply = use identity verified for all rows against Table 4 (commercial fish provisioning 2,800 + wild seed extraction 700 = 3,500; water purification 150 + 50 = 200; all other rows match by construction).
Reading the use table: the supply = use identity holds for every row (commercial fish provisioning 2,800 + wild seed extraction 700 = 3,500; water purification 150 + 50 = 200). Carbon sequestration is attributed entirely to the rest of the world, reflecting its global public-good character. It still counts in GEP at Step 7, because it is supplied by ecosystems within the accounting area; its monetary value should be read with that user attribution in mind. Households take 80% of coastal protection and 85% of recreation, the two shares the dependency indicators in TG-2.3 read.
From the supply and use tables, headline and derived indicators were calculated:
Headline flow indicators:
Intensity indicator matrix (per km² of ecosystem extent):
Table 5a: Intensity indicators by ecosystem type and service, 2025.
Notes on omitted/qualified cells:
Derived dependency indicators:
For demonstration purposes, monetary values were estimated using the following approaches (see TG-1.9 Safe Usage of Monetary Valuation for method details):
Table 6: Monetary ecosystem service account, 2025. The GEP figure above is the sum of final ecosystem service values supplied by ecosystems within the accounting area. In this worked example, no imports of intermediate ecosystem services from outside the accounting area are assumed (the coastal province’s water purification supply does not draw on inland watershed services for the modelled period). In practice, compilers must check for cross-boundary intermediate service flows — e.g., freshwater services from inland watersheds supporting coastal estuarine water purification — and deduct net imports per SEEA EA para. 9.18 to obtain the SEEA-EA-compliant GEP. See Step 7.
Interpretation: The Gross Ecosystem Product (GEP) for the coastal province is approximately USD 54.9 million in 2025 (no intermediate-service net-import deduction applied — see Table 6 note), with coastal protection representing 91% of the total monetary value. This reflects the avoided damage approach, which captures the high value of infrastructure and population at risk in the densely populated coastal zone. Fish provisioning (USD 1.7 million) represents the resource rent accruing to the ecosystem (distinct from the gross value of fish landings, which includes labour and capital inputs). Carbon sequestration has relatively low monetary value (USD 287,500) due to low carbon prices, though the physical quantity (5,750 tC/yr) is substantial. Recreation services (USD 1.3 million) reflect consumer expenditure on marine-based tourism.
The compiled indicators supported several policy applications:
Natural capital budgeting: The provincial government incorporated the GEP estimate (USD 54.9 million) into supplementary budget documents, comparing ecosystem service values with the provincial environment budget (USD 3.2 million), yielding a 17:1 ratio of ecosystem service value to conservation expenditure. This ratio does not represent a benefit-cost analysis, as ecosystem services are sustained by factors beyond government expenditure alone.
SDG 14 monitoring: The fish provisioning indicator (3,500 tonnes commercial harvest) was compared to the sustainable yield estimate (3,200 tonnes from stock assessment). The resulting exploitation rate of 1.09 (9% overfishing) was reported under SDG 14.4.1.
Marine spatial planning: The ecosystem service supply data by ecosystem type were used to evaluate alternative coastal development scenarios, quantifying the trade-offs between converting mangrove areas to aquaculture (loss of carbon sequestration and coastal protection) versus maintaining natural ecosystems.
EGSS compilation: Government expenditure on marine protected area management (CEPA 6), fisheries monitoring (CEPA 6), and mangrove restoration (CEPA 4, CReMA 11) totaling USD 3.2 million was classified as ocean-related EGSS output, enabling comparison with the ecosystem service flows those expenditures aim to maintain. Government fisheries-management expenditure was classified under CEPA 6 in accordance with the Eurostat EGSS reclassification of former CReMA 12 activities (see Table 2 footnote).
Sections 3.3—3.5 present the full compilation guidance for provisioning, regulating, and cultural services indicators respectively. For a cross-cutting comparison of data requirements and feasibility, see Table 1.
Where monetary valuation is undertaken, this section is normative for the choice of method. TG-1.9 Safe Usage of Monetary Valuation remains the guidance on whether and when to value at all, and on how the resulting figures should be communicated; it should be read first. This section sets out how: the value concepts the accounts use, the SEEA EA preference order, the methods at each level, the methods that are not admissible in accounts, and a worked application across four marine ecosystem services.
Asset-level valuation — the net present value of ecosystem service flows, the discount rate, the horizon, and the treatment of degradation and enhancement — is set out in TG-3.1 Asset Accounts Sections 3.3 and 3.5.3, which applies the preference order below to the service flows it discounts.
A key characteristic of ecosystem accounts is that they use exchange values, defined as “the values at which goods, services, labour or assets are in fact exchanged or else could be exchanged for cash.” For the vast majority of entries in national accounts, exchange values are measured using data from observed transactions involving market prices. Market prices are amounts of money that willing buyers pay to acquire something from willing sellers.
Exchange values differ from welfare values, which are commonly used in environmental cost-benefit analysis and include consumer surplus. Consumer surplus is the difference between what is paid for a good or service and what a person is willing to pay. The accounts record the former (exchange value), not the latter (total willingness to pay including surplus).
This distinction has important implications for ocean accounting:
The SNA 2025 clarifies that the integrated framework does not attempt to determine the utility of flows and stocks within its scope. Rather, it measures the current exchange value of entries in the accounts in monetary terms. Exchange values align with national accounting conventions and are the appropriate concept for entries in ecosystem accounts. Welfare values remain important for cost-benefit analysis, but they yield estimates that cannot be directly compared with GDP, national wealth, or other aggregates from the System of National Accounts. Practitioners should use this distinction as a first check when selecting or interpreting valuation studies for ocean accounting purposes.
Ecosystem services as defined in SEEA EA fall outside the production boundary of the SNA. The SEEA EA extends this boundary by recording flows of ecosystem services. This extension creates a framework where:
For ocean accounting, this means that the value of many marine ecosystem services, such as coastal protection, carbon sequestration, and recreation, requires estimation using non-market valuation methods since direct market transactions are rarely observed.
Classifying cultural services as SNA or non-SNA benefits: Because the boundary for cultural services depends on national institutional arrangements, compilers should apply the following three-question checklist before classifying a specific cultural service (e.g., marine recreation by residents):
If the answer to any question is yes, treat the service as contributing to SNA benefits. If the answer to all three questions is no, treat it as contributing to non-SNA benefits. This applies at the level of each specific service flow and beneficiary group. The same marine ecosystem may supply both SNA and non-SNA cultural services to different beneficiaries. See SEEA EA paras. 5.25—5.28 for classification of ecosystem service beneficiaries.
The specific status of different components of SEEA EA affects the authority the valuation guidance below can carry.
The United Nations Statistical Commission at its fifty-second session in March 2021 (Decision 52/101):
Implication for Ocean Accounting: The physical accounting framework has full international statistical standard status. The valuation guidance represents best practice recommendations that countries may apply when undertaking valuation, rather than mandatory requirements. This circular follows these recommendations whilst acknowledging their status.
The characterisation above is drawn directly from the text of UNSC Decision 52/101. The Commission’s choice of the phrase “internationally recognized statistical principles and recommendations” rather than “international statistical standard” for chapters 8-11 was deliberate. At the time of adoption, monetary valuation methods had not reached the same level of methodological maturity as the physical accounting framework in chapters 1-7. In practical terms, this means that countries are encouraged but not required to implement monetary valuation, and where they do so they should follow the principles and recommendations set out in those chapters. Circulars carrying the Core badge draw only on adopted standards, so valuation guidance is presented throughout the Technical Guidance as authoritative best practice rather than as binding statistical standard.
The System of National Accounts 2025 (SNA 2025) was adopted by the United Nations Statistical Commission at its fifty-fifth session in 2024 as the updated international statistical standard for national accounts, replacing SNA 2008. The SEEA EA 2021 valuation recommendations remain the operative guidance for ecosystem accounting pending any future revision of SEEA EA, and SNA 2025 does not amend the SEEA EA valuation chapters. Where this circular cites both SNA 2008 and SNA 2025 paragraph numbers, the SNA 2025 reference is authoritative for current practice.
The SEEA EA establishes a preference order for valuation methods based on their proximity to observed market prices and their alignment with exchange value concepts.
Table 3.10.1 summarises the SEEA EA preference order with examples relevant to ocean accounting.
Table 3.10.1: SEEA EA valuation method preference order
Note on replacement cost and preference level: Replacement cost belongs at Preference Level 5 (expected/simulated expenditure) in the large majority of ocean accounting applications, because the replacement structure (e.g., a seawall, constructed wetland) is hypothetical: it has not been built and its cost has not been observed. Replacement cost may be classified at Level 4 only in the exceptional case where an equivalent replacement has actually been constructed and the observed construction costs are available from administrative records. See Section 3.10.4 for full guidance on applying these methods.
Methods at lower preference levels introduce greater uncertainty and require stronger assumptions. Where feasible, compilers should aim for methods at preference levels 1-3, which rely on observed market data. Because methods at levels 4-5 rest on weaker assumptions, their application should be accompanied by explicit documentation of assumptions and sensitivity analysis.
The following decision tree provides a simplified guide to selecting a valuation method based on data availability, following the SEEA EA preference order from most to least preferred. Figure 2.4.2 traces this five-level preference order. Each data-availability gate routes compilers from directly observed prices at Level 1 to modelled expected costs at Level 5.
· Figure 1.9.1
Source TG-1.9 Valuation Methods, Section 3.4 (five-level preference hierarchy) and Table 1.
Sections 3.10.3 and 3.10.4 set out methods for preference levels 1-3 and 4-5 respectively, each with specific ocean accounting examples and worked calculations.
Where prices are directly observable in market transactions, these provide the most reliable basis for valuation. Examples relevant to ocean accounting include:
These directly observed values reflect the current institutional context and should be applied in accounts even when the resulting values might appear “low” relative to the perceived importance of the ecosystem. As the SEEA EA notes, resource rents for natural resources extracted in open-access contexts will tend toward zero, and this is a well-understood result that reflects institutional arrangements rather than low ecosystem importance.
Care should be taken to understand the size of markets and their maturity because the use of prices from small or immature markets may not be sufficiently representative for use in ecosystem accounting. To the extent that the recorded values are considered ‘low’, there may be an interest in estimating complementary values on the basis of alternative institutional contexts and market settings. These hypothetical values should not be recorded in ecosystem accounts but may be presented in complementary accounts.
When market prices for a specific ecosystem service are not observable, prices from markets for similar goods and services may provide an approximation. The SNA states that “if there is no appropriate market in which a particular good or service is currently traded, the valuation of a transaction involving that good or service may be derived from the market prices of similar goods and services by making adjustments for quality and other differences.”
For ocean accounting, this might include:
Caution: Value transfer across different institutional and ecological contexts requires careful adjustment for differences. Institutional mismatch (where source study contexts differ from accounting application contexts) is a risk. The most widespread example of applying this approach in the national accounts is the estimation of the imputed rent for owner-occupied dwellings, where the observed rents paid by tenants are commonly used to apply a ‘similar markets’ method to estimate rents for owner-occupied dwellings (adjusting for variations in rents associated with the location and characteristics of the dwellings).
These methods estimate ecosystem service values from data on market transactions where the ecosystem contribution is embedded but not directly observable:
Residual Value and Resource Rent Methods
The resource rent method estimates value by taking gross output value and deducting costs of all other inputs including labour, produced assets, and intermediate inputs. For marine fisheries, this means:
The residual represents the contribution of the marine ecosystem to the production value. This method is commonly applied for valuing wild fish provisioning services. This formulation follows the structure set out in SEEA CF Annex A5.1, which defines the resource rent as the residual after deducting all user costs of produced assets and labour from the gross value of output. In the fisheries context, the inclusion of an imputed cost of self-employed labour is essential, as owner-operators are common in many small-scale fisheries, and omitting this cost would inflate the residual. Similarly, the return on produced assets (i.e. normal profit on the capital invested in vessels and gear) must be deducted to isolate the ecosystem contribution from the return to produced capital.
Taxes on production net of subsidies, including resource access fees, licence fees, and royalties payable to the resource owner (commonly government), must also be deducted explicitly. In jurisdictions where government retains resource ownership, access fees represent a transfer of the resource rent to the state. Omitting them causes the compiler-calculated residual to overstate the unappropriated rent and risks double-counting government revenue already recorded in national accounts.
The calculation is subject to variations in prices of outputs and inputs that can be considerable under market conditions, resulting in high annual volatility of estimates. For this reason, statistical offices tend to use 3-5 year moving averages when calculating residual value.
Hedonic Pricing
Estimates the differential premium on property values derived from proximity to marine and coastal environmental attributes such as beach quality, water clarity, or marine protected areas. This method is particularly relevant for valuing coastal amenity and visual amenity services. Applications of hedonic pricing have grown substantially in recent years, with studies documenting property premiums for nature views, open spaces, beach access, and water quality.
Productivity Change Method
Estimates value based on the marginal contribution of ecosystem inputs to production functions. For ocean contexts, this includes estimating the productivity contribution of:
The productivity change method estimates an exchange value that is consistent with the SNA by estimating a production function directly, based on micro-level data on physical inputs and outputs at the site (e.g. farm) level. The econometric estimation of the equation provides a direct estimate of the marginal productivity of the input(s). Multiplying the marginal productivity by the price of the output gives the exchange value of the ecosystem service. Such a method requires the availability of micro data to make the estimation, which can be data intensive.
These methods derive prices from actual expenditures on related goods and services that have already been made and are observable in administrative or survey data.
Boundary between averting behaviour and replacement cost: This distinction applies before selecting a Level 4 method. Averting behaviour (defensive expenditure) requires that an actual expenditure has been made and recorded: it is a real cost that appears in national accounts or administrative data. Where the expenditure is hypothetical (the replacement or protective structure has not been built and its cost has not been observed), the correct method is replacement cost at Preference Level 5, not Level 4. Compilers must verify that an actual expenditure record exists before applying a Level 4 cost-based method. The mere plausibility of a future expenditure does not qualify. See Section 3.10.4 for replacement cost guidance.
Averting Behaviour (Defensive Expenditure)
Based on expenditures to mitigate or eliminate damages from adverse environmental impacts. Ocean examples include:
Travel Expenditure
Uses travel costs as a proxy for recreation service values. The consumer expenditure method, which uses direct out-of-pocket expenditures (transport, fuel, accommodation, fees), provides exchange values appropriate for accounts. This differs from the traditional travel cost method that estimates total willingness to pay including consumer surplus.
For marine and coastal recreation, consumer expenditure data from tourism statistics can provide a basis for valuation, though care is needed to:
Where observed prices and expenditures are not available, methods based on expected or simulated expenditures may be applied:
Replacement Cost
Estimates the cost of replacing a single ecosystem service using a process that provides equivalent benefits. For ocean accounting, common applications include:
Validity conditions: The replacement must (i) provide exactly the same function, (ii) be the least-cost alternative, and (iii) have evidence of actual demand.
Avoided Damage Cost
Estimates value based on the costs of damages that would occur due to loss of services. This is particularly relevant for coastal protection services, where avoided damages from storm surge, flooding, and erosion can be estimated using flood risk models. The validity of the avoided damage cost method depends on conditions including that the damages avoided can be related to a specific service, and that people would be willing to pay an amount to actually avoid the damage.
Simulated Exchange Value (SEV)
Estimates the price and quantity that would prevail if the ecosystem service were traded in a hypothetical market. The SEV method uses demand curves estimated from travel cost or stated preference studies to simulate what price would clear a hypothetical market for the service. Whilst more complex, this method can provide exchange-value-consistent estimates where other methods are not feasible.
Case illustration: UK Marine Natural Capital Accounts (JNCC/Cefas) The UK Joint Nature Conservation Committee (JNCC) and Centre for Environment, Fisheries and Aquaculture Science (Cefas) compiled an initial set of natural capital accounts for UK marine and coastal ecosystems. At the time of their study, an estimated 36% of UK marine habitats were classified as unmapped or unknown. For those habitats where data were available, the study applied several valuation methods consistent with SEEA principles: replacement cost for waste mediation (phosphorus, nitrogen, BOD) by littoral sediments, coastal saltmarsh, shelf-sea, and deep-sea ecosystems; replacement cost for coastal protection based on the cost of constructing equivalent seawalls; abatement cost for carbon burial in marine sediments; and the resource rent approach for marine fish and shellfish, offshore renewable energy (wind), and abiotic products (marine aggregates). This study illustrates both the feasibility of applying the SEEA EA preference order to marine assets and the practical constraint that incomplete habitat data imposes on full valuation coverage.
Certain valuation methods, whilst useful for other analytical purposes, do not yield exchange values appropriate for direct recording in ecosystem accounts.
Methods that estimate total willingness to pay including consumer surplus are not appropriate for direct entry in accounts. Consumer surplus cannot be transferred between transactors and represents value that is not exchanged. However:
Contingent valuation and choice experiment results that estimate total willingness to pay should not be directly entered in accounts. Stated preference data that have not been adjusted for exchange value consistency are not appropriate account entries regardless of data availability or the absence of alternative methods.
Appropriate use of stated preference data: If stated preference data are the only available source for a given service, they should be used only as inputs to SEV calculations, adjusting for consumer surplus to derive the simulated exchange value, and clearly flagged as Level 5 estimates requiring sensitivity analysis. They should not be entered as direct account values. Compilers using stated preference data in this way should cross-reference Section 3.10.4 on SEV methodology and document the adjustment procedure explicitly.
Other appropriate uses:
Non-use values (existence values, bequest values, option values) are not within scope of ecosystem service values in accounts since there are no inherent transactions associated with these values. This exclusion matters for ocean accounting given the high perceived non-use values associated with:
Whilst these values may be relevant for wider policy analysis and public communication, they represent a different measurement concept that should not be mixed with exchange-value-based accounts. Where non-use values are considered important for policy purposes, the SEEA EA framework accommodates their presentation through complementary accounts and thematic analyses. Chapter 12 of the SEEA EA describes how welfare values, including non-use values, can be reported in supplementary tables alongside exchange-value-based accounts, using a bridge-table approach that makes the relationship between the two measurement concepts explicit. This approach allows policymakers to access information on non-use values without compromising the conceptual integrity of the core accounts. For ocean accounting, compilers may wish to consider producing such complementary analyses for ecosystem types or species where non-use values are known to be large relative to exchange values, such as iconic marine habitats and species.
The SEEA EA distinguishes between replacement costs (appropriate for individual services) and restoration costs (the cost of restoring an ecosystem as a whole). Restoration costs should not be used to value ecosystem assets, as this would make it impossible to separately assess the benefits of ecosystem restoration: they would by definition equal the costs. However, restoration costs can provide policy-relevant information in certain contexts and may be presented in complementary accounts.
The following worked example covers a coastal marine ecosystem and illustrates step-by-step method selection for multiple ecosystem services supplied by a hypothetical coastal accounting area.
Accounting Area: A coastal region encompasses 500 hectares of mangrove forest, 200 hectares of coral reef, and 5,000 hectares of continental shelf waters. The area supports commercial fisheries (targeting reef and pelagic fish), recreational diving, and provides coastal protection to 10 km of populated coastline. An ITQ system for fishing is not in place; catch is managed through annual total allowable catch (TAC) limits. Carbon markets operate at national level with verified blue carbon offsets for mangrove conservation.
Objective: Compile monetary values for four key ecosystem services (fish provisioning, coastal protection, carbon sequestration, and recreation) using the SEEA EA preference order.
Step 1: Check for directly observable prices (Preference 1)
Step 2: Check for similar markets (Preference 2)
Step 3: Apply prices embodied in transactions (Preference 3)
Calculation:
Note: The taxes/access fees line is shown explicitly as nil here because the illustrative jurisdiction has no royalty or licence fee regime. In jurisdictions where government charges access fees or royalties, this line will carry a positive deduction. Omitting it where fees exist would overstate the resource rent.
Result: Fish provisioning service valued at USD 500 per tonne using resource rent method (Preference level 3). This represents the ecosystem contribution after deducting all other input costs. See also TG-1.9 Section 3.2.4: because resource rent is used here, nursery habitat services from the reef should not be separately valued in this account.
Step 1: Check for directly observable prices (Preference 1)
Step 2: Distinguish physical service flow from monetisable verified credits
The physical service flow (gross CO2 sequestration) is the quantity recorded in the physical account. The monetary value attaches to the verified offset credits that can be issued against that sequestration. The two quantities differ because verified carbon markets apply permanence buffers and leakage deductions to manage the risk that sequestered carbon is not permanently retained.
Calculation:
Where no verified credits exist: If the jurisdiction has no operating verified carbon offset market, do not apply prices from other markets directly. Instead, use a Level 5 simulated exchange value method (Section 3.10.4), and document the method and assumptions explicitly.
Result: Carbon sequestration service valued at USD 51,000 annually using observed carbon credit prices applied to net verified credit units (Preference level 1). The gross physical flow of 4,000 t CO2/year is recorded separately in the physical account.
Step 1: Check for directly observable prices (Preference 1)
Step 2: Check for similar markets (Preference 2)
Step 3: Check for prices embodied in transactions (Preference 3)
Step 4: Assess validity conditions for replacement cost (Preference 5)
Validity conditions test:
If any condition cannot be demonstrated, the method should be applied at Level 5 with correspondingly stronger uncertainty documentation and sensitivity analysis, and the failed condition flagged in the disclosure statement.
Calculation:
Result: Coastal protection service valued at USD 5,586 annually using replacement cost method (Preference level 5). Sensitivity analysis should be conducted on asset life (30-70 years) and discount rate (3-5%).
Step 1: Check for directly observable prices (Preference 1)
Step 2: Check for similar markets (Preference 2)
Step 3: Check for prices embodied in transactions (Preference 3)
Step 4: Apply revealed expenditure methods (Preference 4)
Calculation — raw expenditure:
Step 5: Isolate the marine ecosystem component
Not all trip expenditure is attributable to the marine ecosystem service. Accommodation costs (USD 35 of USD 80) serve the overnight stay regardless of the marine destination, and they should generally be excluded unless the marine attribute is demonstrably the primary trip driver. One accepted allocation approach uses visitor motivation data:
Where motivation survey data are not available, a conservative approach is to include only purpose-specific fees (transport and dive fees) and exclude accommodation. Compilers should document the allocation method and reference tourism satellite account methodology for multi-purpose trips.
Result: Recreation service valued at approximately USD 1,016,250 annually using consumer expenditure method with marine motivation allocation (Preference level 4). Care must also be taken to avoid double-counting with coastal property amenity values already captured in any hedonic pricing estimate.
Table 3.10.2: Valuation method selection summary
Interpretation: These four services were selected specifically to be non-overlapping for this illustrative example: they have distinct beneficiary populations (fishing industry, carbon market participants, coastal residents, recreational visitors) and draw on distinct ecosystem processes (provisioning, carbon cycling, physical protection, amenity). Because of this non-overlap, the four values can be summed to an indicative total of approximately USD 2,072,836 for this accounting area. In real compilations, compilers must confirm non-overlap before summing service rows (see TG-1.9 Section 3.2.4 for double-counting cautions, including the specific rule that nursery habitat services must not be separately valued when resource rent is used for fish provisioning). The corrected coastal protection value of USD 5,586 reflects the annuity factor of 21.48 at 4% over 50 years. All values should be presented alongside physical accounts showing mangrove extent, reef condition, fish stock biomass, and visitor numbers.
This section synthesises the four service values from Table 3.10.2 into a simplified ecosystem asset value using the net present value (NPV) approach. This is an introductory illustration only. TG-3.1 provides full guidance on ecosystem asset accounts.
Step 1: Annual service flow
Step 2: Projection assumption
For this simplified illustration, assume constant real service flows over the asset life (no growth or decline trend). In practice, compilers should assess whether a trend, positive (e.g., reef restoration) or negative (e.g., climate-related degradation), is observable and use that trend in the projection. TG-3.1 discusses projection methods in detail.
Step 3: Discount rate
Illustrative rate: 4% social discount rate (reflecting a mix of collective-benefit services in this portfolio). See TG-1.9 Section 3.1.2 for guidance on rate selection. Sensitivity analysis is mandatory.
Step 4: Time horizon
Illustrative horizon: 50 years (broadly consistent with planning horizons for coastal ecosystems). This is a practical simplification. Ecosystem assets are long-lived, and a perpetuity formula may be more appropriate in some contexts.
Step 5: NPV calculation
Table 3.10.3: Sensitivity analysis — ecosystem asset NPV
The sensitivity table demonstrates that the asset value is sensitive to both discount rate and time horizon assumptions. The spread between the 3%/50-year and 7%/30-year estimates is nearly twofold. Transparent disclosure of these assumptions is therefore essential. See TG-3.1 for full ecosystem asset account methodology, including how to handle multiple service types with different discount rates, depreciation of ecosystem assets, and time-series consistency.
Authors: [To be confirmed]
Reviewers: [To be confirmed]
Cite this report
Environmental (including Ecosystem) Goods and Services (2026) (GOAP Technical Guidance on Ocean Accounting, TG-2.4, v0.8.4). GOAP Secretariat. https://guidance.oceanaccounts.org/circulars/section-2/2-4-ecosystem-goods-services/
guidance.oceanaccounts.org/circulars/section-2/2-4-ecosystem-goods-services
© 2026 Global Ocean Accounts Partnership Secretariat · CC BY-NC 4.0 · The report, its PDF and this deck are built from the same source.
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