Economic Activity Relevant to the Ocean

3.1 Why ocean economy accounts are compiled

Three families of decision drive demand for these accounts, and they shape compilation priorities. Budget justification requires the ocean economy’s contribution to national income and employment, to weigh public expenditure on ocean management, fisheries governance, port infrastructure and marine environmental protection. Economic planning requires the relative importance of ocean industries, their productivity and capital intensity, and the trend in each. Investment analysis and sustainable finance require capital formation by ocean industry and its relationship to output growth.

Which account and which indicator answer each of these, and what an ocean economy figure can and cannot be used to claim, are set out in TG-1.0 Ocean Accounting and the Blue/Ocean Economy, whose Section 3.4 carries the routing table. This Circular supplies the account those decisions read: the boundary, the concordance, the supply and use table and the aggregates derived from it.

Terminology follows TG-1.0 Section 3.2. This Circular measures the ocean economy; the accounting framework below can accommodate a different definitional choice, provided the scope and boundaries adopted are documented.

3.2 Defining the Ocean Economy

The ocean economy (also referred to as the ‘marine economy’ or ‘blue economy’) comprises the economic activities that derive outputs from the ocean, use the ocean as an input to production, or provide goods and services directly to ocean-related activities. This definition encompasses a spectrum from activities entirely dependent on the ocean (such as marine fishing) to activities that are partially ocean-related (such as coastal tourism, where visitors may engage in both marine and non-marine activities).

The following decision flowchart guides the classification of a candidate activity:

1. Does the activity directly extract resources from, operate on, or harvest products from the ocean? Yes → Ocean-dependent (Tier 1, ratio = 1.0). No → proceed to step 2.
2. Does the activity provide goods or services predominantly to ocean-dependent activities, or process ocean-origin products? Yes → Ocean-related (thematic scope, ratio estimated directly). No → proceed to step 3.
3. Is ocean-attributable revenue a material share of establishment output (indicatively, around 5 per cent or more)? Yes → Partially ocean-related (Tier 1, ratio to be estimated). No → Exclude from ocean economy accounts.

This seven-part framework synthesises approaches from multiple sources, including the OECD (2016), various national ocean economy programmes, and the broader environmental-economic accounting literature. It should be understood as a complementary applied categorisation, not a classification prescribed by the SEEA or SNA. Categories 1—4 define the core scope used by most national ocean economy programmes. Categories 5—7 extend the measurement boundary for advanced analytical applications.

The SNA 2025 explicitly identifies oceans as an area where the core ecosystem accounting framework can be applied using thematic and extended accounting principles (para 35.63), and SEEA Ecosystem Accounting describes thematic accounting for oceans as a specific application (para A1.135).

The spatial dimension of the ocean economy intersects with the concept of Economic Exclusive Zones (EEZs) established under the United Nations Convention on the Law of the Sea (UNCLOS). A country’s ocean economy includes:

• Activities occurring within its territorial waters and EEZ
• Activities by resident enterprises operating in international waters (such as distant-water fishing fleets), recorded as production of resident units
• Coastal and land-based activities that serve ocean-related purposes (such as ports and fish processing plants)

Activities by non-resident units operating within a country’s EEZ under licence or quota arrangements require careful treatment. The SNA 2025 addresses this specifically: when non-resident units make use of quota established for fishing in a country’s EEZ, the coastal state is treated as owning the fish stocks, with the licence fees representing rent payments from the non-resident fishing enterprise to the coastal state.

Two requirements follow. The boundary adopted should be documented explicitly and applied consistently across time periods, as an inland boundary that moves between periods makes a trend series uninterpretable. It should also be disclosed in the metadata accompanying any published aggregate: differences in inland boundary choice are a primary source of cross-country non-comparability, and a figure that does not state its inland boundary cannot be compared with another country’s.

Relationship to ecosystem services

The ocean economy as defined here is distinct from the ecosystem services supplied by marine ecosystems, though the two are related. Ecosystem services represent the contributions of ecosystems to economic activity and human well-being. The ocean economy, in contrast, represents the economic activities themselves. Fish harvested from the ocean represents an ecosystem service (biomass provisioning). The fishing industry that conducts the harvest is part of the ocean economy. The link between these concepts is addressed in TG-2.4 Ecosystem Goods and Services and TG-3.2 Flows from the Environment to the Economy.

3.3 Ocean Economy Thematic and Extended Accounts

The most statistically consistent approach to measuring the ocean economy applies thematic and extended accounting principles from the System of National Accounts. The SNA 2025 describes these as accounts that provide complementary data allowing insight into a key activity or aspect of the economy that lacks visibility in the integrated framework of national accounts (formerly known as ‘satellite accounts’). The Tourism Satellite Account (TSA) provides a well-established model that has been adapted for ocean economy measurement in several countries.

Structure of ocean economy thematic and extended accounts

An ocean economy thematic account typically comprises the following components:

Production accounts by ocean industry — for each ocean-related industry, recording output, intermediate consumption, and gross value added. These accounts follow the structure of SNA production accounts but provide detail for ocean-specific industries that may be aggregated in standard national accounts.

Supply table for ocean-characteristic products — recording the supply of ocean-characteristic products by producing industry (ocean and non-ocean industries), imports, and adjustments for taxes less subsidies and trade margins.

Use table for ocean-characteristic products — recording the use of ocean-characteristic products as intermediate consumption by industry, final consumption by households and government, gross fixed capital formation, and exports.

Employment accounts — recording the number of persons employed, jobs, hours worked, and full-time equivalent employment in ocean industries, potentially disaggregated by occupation, status in employment, and demographic characteristics. See International Recommendations for Tourism Statistics 2008 Chapter 7 for methodological guidance on employment measurement in sector thematic accounts.

Gross fixed capital formation — recording investment in ocean-related produced assets, including vessels, port infrastructure, aquaculture facilities, and offshore platforms.

Connection to wider accounts — documenting the relationship between ocean economy aggregates and national totals, including the ocean economy’s share of GDP, employment, and exports.

The Classification of the Functions of Government (COFOG) identifies government expenditure on ocean-related functions, such as environmental protection of marine areas, fisheries management, and maritime safety. This expenditure data complements the production-focused thematic accounts described above. Linking COFOG-classified government expenditure with ocean economy production accounts supports analysis of public spending in relation to ocean economic activity. Detailed guidance on integrating government fiscal data with ocean accounts is provided in TG-1.1 Budget Processes.

The identification and classification of ocean-related industries underpins the compilation of ocean economy accounts. The International Standard Industrial Classification of All Economic Activities (ISIC) provides the internationally agreed framework for classifying economic activities by industry. ISIC Revision 4 remains the current international standard widely implemented in national statistics, although ISIC Revision 5 was endorsed by the UN Statistical Commission in March 2024 with implementation expected from 2027.

ISIC Rev.5 was endorsed by the UN Statistical Commission in March 2024, but full implementation in national statistical systems typically requires several years of preparatory work including development of national adaptations, correspondence tables, and back-casting of historical series. Compilers should ascertain which version of ISIC (or its national adaptation) is currently in use in their country’s business register and economic surveys, and use the relevant correspondence tables when mapping between ISIC versions.

The following ISIC Rev.4 categories represent the core ocean-dependent industries:

Division 03 — Fishing and Aquaculture

• Class 0311 Marine fishing — fishing on a commercial basis in ocean and coastal waters, including taking of marine crustaceans, molluscs, and other marine organisms
• Class 0312 Freshwater fishing — included when freshwater systems connect to marine environments or support anadromous species
• Class 0321 Marine aquaculture — farming of marine fish, crustaceans, molluscs, seaweed, and other aquatic organisms in marine or brackish waters
• Class 0322 Freshwater aquaculture — may be relevant for integrated coastal aquaculture systems

Division 50 — Water Transport

• Group 501 Sea and coastal water transport
  • Class 5011 Sea and coastal passenger water transport — including ferries, cruise ships, and excursion boats
  • Class 5012 Sea and coastal freight water transport — including container shipping, tankers, and bulk carriers
• Group 502 Inland water transport — relevant where inland waterways connect to marine transport systems

Division 06 — Extraction of Crude Petroleum and Natural Gas

• Class 0610 Extraction of crude petroleum — includes offshore oil extraction
• Class 0620 Extraction of natural gas — includes offshore gas extraction
• Class 0910 Support activities for petroleum and natural gas extraction — includes offshore support services

Division 35 — Electricity, Gas, Steam and Air Conditioning Supply (partial)

• Class 3510 Electric power generation, transmission and distribution — includes offshore wind, tidal, and wave energy generation (requires disaggregation from land-based generation)

Specific guidance on offshore energy accounting is provided in TG-3.10 Offshore Energy.

Additional industries are partially ocean-related and require estimation of their ocean-related share:

Manufacturing

• Class 1020 Processing and preserving of fish, crustaceans and molluscs
• Class 3011 Building of ships and floating structures
• Class 3012 Building of pleasure and sporting boats
• Class 3315 Repair of transport equipment (partial — for ship repair)

Transportation and storage

Emerging sectors and blue technology. Innovative ocean technologies — including marine renewables, marine biotechnology, robotic marine vehicles, and advanced ICT applications in marine contexts — are often not yet codified in ISIC and may be small relative to core sectors in the early years of production. Best practice, consistent with EU and OECD approaches, is to report these sectors separately from core accounts at a level of detail appropriate to available information, rather than integrating them into existing ISIC classes where no code exists.

For industries that are only partially ocean-related, the ocean economy share — the ocean ratio — must be estimated. It is directly analogous to the ‘tourism ratio’ of the SF-MST (paras 4.50—4.53), which estimates the share of an industry’s output attributable to tourism demand. This subsection is the single source for ocean-ratio estimation across the publication; TG-2.2, TG-2.5 and TG-2.11 apply the ratios derived here and do not restate the method.

Default allocation key where an enterprise straddles the boundary. A single enterprise may span ocean and non-ocean activity under one ISIC code — a processor handling both marine and freshwater species, a coastal energy company with offshore and onshore operations. The recommended default key is revenue share from ocean versus non-ocean sales in the reference year: a processor deriving 70 per cent of revenue from marine species attributes 70 per cent of its GVA to the ocean economy. Whichever key is chosen must be documented and applied consistently across the entire time series; changing it between years introduces a structural break that must be flagged in the metadata.

Indicative starting ranges, where nothing better exists. These are pragmatic anchors for a first compilation at level 4, not standards-derived values, and they should be replaced as soon as level 1—3 data become available. Fish processing (ISIC 1020): 0.70—0.90, reflecting typical industry structures in small island and coastal states. Coastal accommodation (ISIC 5510): 0.30—0.50. Ratios outside these ranges require additional justification in the metadata.

Employment measure. Where ocean employment is compiled, the primary measure is headcount (persons employed in the reference period), consistent with what labour force surveys typically support. Report full-time equivalent (FTE) employment additionally where source data permit, in line with the SNA 2025 recommendation that FTE is preferred for comparability where part-time and seasonal work is significant. FTE matters most for coastal accommodation, tourism-related and small-scale fisheries activity. The chosen measure must be applied consistently to both numerator and denominator of any employment share, and documented.

The approach for tourism follows the Tourism Satellite Account methodology, where the ‘tourism ratio’ concept is adapted to estimate the share of tourism industries attributable to coastal and marine tourism, . Detailed guidance on survey methods is in TG-4.2 Survey Methods for Ocean Economic Activity, and on administrative data sources in TG-4.3 Administrative Data Sources. Multi-agency compilation has been demonstrated in practice: Canada’s marine economy accounts draw on Fisheries and Oceans Canada, Natural Resources Canada, Transport Canada and Statistics Canada.

3.5 Supply and Use Tables

Using the industry categorisation in Section 3.4 above and the ISIC-ocean economy concordance in Table 2 below, identify all ISIC Rev.4 classes that constitute the ocean economy in the compiling country. For each class, determine whether it is wholly ocean-dependent (ocean ratio = 1.0) or partially ocean-related (ocean ratio < 1.0). This classification corresponds to the identification of ‘tourism characteristic activities’ in the SF-MST framework.

Step 2: Identify ocean-characteristic products via CPC concordance

Determine which products are wholly or partially ocean-characteristic, using the Central Product Classification (CPC) aligned with ISIC industry classifications. Ocean-characteristic products include:

• Fish and fishery products — Live fish and other fishing products (CPC Division 04); Processed and preserved fish products (CPC Group 212)
• Marine transport services — Sea and coastal water transport services (CPC Divisions 65—67); Port services, pilotage, and lighterage
• Offshore extraction products — Crude petroleum from offshore sources; Natural gas from offshore sources; Offshore mineral products
• Marine tourism and recreation services — Coastal accommodation services (partial); Marine recreational services

Step 3: Extract ocean economy sub-matrices from national SUTs

From the balanced national supply and use tables, extract the columns corresponding to identified ocean economy industries and the rows corresponding to ocean-characteristic products. This creates ocean economy supply and use tables that are subsets of the national tables (SNA 2025 Chapter 15, para 15.9). If the national SUTs are published at a level of aggregation above individual ISIC classes, compilers may need to use supplementary data sources—business surveys (TG-4.2) and administrative records (TG-4.3)—to disaggregate the relevant columns and rows.

Step 4: Determine ocean economy ratios

For partially ocean-related industries, estimate the ocean ratio using the method hierarchy, the default allocation key and the indicative ranges in Section 3.4 above. Record the level used for each industry in the metadata.

Step 5: Balance the ocean economy SUT

Reconcile supply and use for each ocean-characteristic product, resolving discrepancies through quality assessment and adjustment. The balancing process improves the consistency and reliability of the accounts. SNA 2025 Chapter 15 (paras 15.130—15.139) provides detailed guidance on balancing procedures, including use of commodity flow methods, confrontation of supply and demand estimates, and iterative adjustment.

Step 6: Derive GVA, employment, trade aggregates

From balanced ocean economy SUTs, derive gross value added by industry (output less intermediate consumption), total ocean economy GVA, ocean economy employment, ocean economy exports, and ocean economy GFCF:

$\text{Ocean Economy Direct GVA}=\sum _i({\text{GVA}}_i\times {\text{Ocean ratio}}_i)$Ocean Economy Direct GVA=i∑​(GVAi​×Ocean ratioi​)

Summing GVA rather than output avoids double-counting inter-industry transactions by construction: the supply-use identity has already netted each industry’s intermediate purchases out of its value added, so marine fishing (ISIC 0311) and fish processing (ISIC 1020) may both be included without double-counting the seafood supply chain.

Step 7: Adjust for taxes less subsidies on products

To derive Ocean Economy Direct GDP from Ocean Economy Direct GVA, add the ocean-related share of taxes less subsidies on products:

$\text{Ocean Economy Direct GDP}=\text{Ocean Economy Direct GVA}+\text{Ocean share of (taxes}-\text{subsidies on products)}$Ocean Economy Direct GDP=Ocean Economy Direct GVA+Ocean share of (taxes−subsidies on products)

The ocean share of product taxes and subsidies can be estimated in proportion to the ocean economy’s share of total final expenditure on ocean-characteristic products.

These aggregates provide the foundation for the structural indicators in TG-2.5 Ocean Economy Structure, the dependency indicators in TG-2.2 Macro-level Dependencies, and the efficiency indicators in TG-2.11 Resource Efficiency.

Ocean economy supply-use table template

Table 1 provides a template for the ocean economy supply-use table in monetary terms. The supply table records the output of ocean-related products by ocean industries, whilst the use table records the intermediate consumption, final demand, and value added for each industry. This template follows the structure established in SNA 2025 Chapter 38 for thematic and extended accounts.

Table 1: Ocean Economy Supply-Use Table Template (Basic Prices, currency units)

SUPPLY TABLE

USE TABLE

The supply-use identity requires that Total Supply = Total Use for each product. GVA for each industry provides the primary measure of the ocean economy’s contribution to GDP.

Table 2 maps ISIC Rev.4 industry codes to ocean economy activities, identifying the relationship type and recommended estimation approach. This concordance supports the identification and measurement of ocean industries within existing national statistical frameworks.

Table 2: ISIC Rev.4 to ocean economy concordance, with the allocation key and preferred data source for each partially ocean-related class. Illustrative: compilers should develop a country-specific concordance adapted to their national industry classification, and record the estimation level from Section 3.4 for each partial.

For ‘ocean-dependent’ industries (100% attributable), the full output of the ISIC class is included. For ‘partial’ industries, the ocean share must be estimated using supplementary data such as administrative records or surveys. For ‘ocean-related’ industries, professional judgement and data analysis determine inclusion.

3.6 Capital Formation in the Ocean Economy

Gross fixed capital formation (GFCF) in ocean industries, and expenditure on marine environmental protection, are compiled on the same industry basis as the ocean economy SUT above. This section specifies the classification decisions those compilations require. The indicators derived from them — public and private investment indicators, sustainable ocean finance, tracking methodology — are TG-2.6 Ocean Investment.

Adoption of a tier beyond basic should be documented in the methodological notes. Compilers using only the basic tier should not present the resulting table as exhaustive of ocean-related investment.

These scope tiers describe what to measure. They are distinct from, and orthogonal to, the data-maturity compilation pathway in TG-2.6 Section 3.5 (Foundational, Developing, Advanced), which describes what a compiler can produce given available data. A country at an early data-maturity stage may still target extended scope. The two axes should not be conflated.

Restoration expenditure: capitalisation decision tree

For the non-produced asset dimension (treatment of the ecosystem itself), compilers should consult SNA 2025 Chapter 11 on biological resources and the SEEA Ecosystem Accounting (SEEA EA) Chapter 3 on ecosystem asset delineation, with monetary asset and restoration treatment elaborated in SEEA EA Chapters 10-12.

Residence and economic ownership for ocean assets

Investment measurement follows the residence principle of the SNA, attributing investment to the economic territory where the producing unit is resident. The governing attribution principle is economic ownership: the residence of the institutional unit that bears the economic risk and reward associated with the asset, not the flag of registration. For ocean activities, this creates specific considerations:

• Investment in vessels operated by a resident economic owner is attributed to the country of residence of that owner, regardless of the flag under which the vessel is registered.
• Offshore installations within a country’s Exclusive Economic Zone (EEZ) are treated as being within the economic territory of the coastal state.
• Investment by non-resident enterprises operating under licence within the EEZ (such as foreign fishing fleets) is attributed to the country of residence of the enterprise.

Interim guidance for ABNJ-adjacent investment. Pending updated guidance from GOAP or the UN Statistics Division on BBNJ-related statistical treatment, compilers preparing 2025 and 2026 ocean accounts should:

1. Apply the SNA residence principle as the default rule: investment in ABNJ-related activities (deep-sea mining, high-seas fishing, BBNJ-linked biodiversity offset instruments) is attributed to the economic territory of the investing institutional unit.
2. Flag ABNJ-related investment as a separate memorandum item beneath the main ocean investment totals, so that future revision is straightforward when authoritative guidance is issued.
3. Retain full documentation of classification decisions (instrument, activity location, residence determination, taxonomy applied) to enable retrospective revision.

Classification rule: avoiding double-count between GFCF and EPEA

3.7 Worked Example: Ocean Economy SUT for Country A

To illustrate the compilation procedure, this section presents a worked example for a hypothetical medium-income coastal state (‘Country A’) with a total GDP of approximately USD 50 billion, total employment of 10 million persons, and an ocean economy representing 3.5 per cent of GDP. All monetary values are expressed in millions of USD. The example demonstrates how the ocean economy SUT template (Table 1) is populated with synthetic data consistent with the structural indicators presented in TG-2.5 Ocean Economy Structure Section 3.2 (Table 3.1).

Country A has:

• A diversified ocean economy dominated by coastal tourism (32% of ocean GVA) and offshore oil and gas (24%)
• Maritime transport and port operations contributing 18% of ocean GVA
• A traditional marine living resources sector (fishing, aquaculture, fish processing) contributing 10%
• Emerging marine renewable energy sector (offshore wind) contributing 4%
• Shipbuilding and ‘other ocean industries’ (marine research, maritime education, coast guard) making up the remainder

The compilation follows the seven-step procedure in Section 3.5, extracting ocean industry columns from national SUTs and applying ocean economy ratios to partially ocean-related industries.

Simplified ocean economy supply table (Country A)

Table 3 presents a simplified supply table for eight ocean-characteristic product groups and seven ocean industry groups. The table records domestic production by industry (columns 2—8), imports (column 9), and total supply (column 10).

Table 3: Ocean Economy Supply Table, Country A (million USD, basic prices)

The industry column totals show gross output for each ocean industry. The rightmost figure (3,559) is total supply of the eight ocean-characteristic product groups: domestic output of 3,225 plus imports of 334. It must equal total use of those same products in the balanced SUT.

Ocean industries also buy inputs that are not ocean-characteristic products — fuel bought ashore, insurance, professional services, construction materials. Those products are supplied by non-ocean industries and lie outside the extracted sub-matrix, so they are carried as a single memorandum row rather than being attributed to an ocean industry column. Recording them inside an ocean product row is a common compilation error: it inflates that product’s use above its supply and breaks the balance for the row.

Simplified ocean economy use table (Country A)

Note: The table is balanced. Every product row satisfies total supply (Table 3) = total use, every industry column satisfies output = intermediate consumption + GVA, and the industry Total Output row (USD 3,225M) equals the corresponding totals in Table 3. Total intermediate consumption is USD 1,535M and GVA is USD 1,690M (= 3,225 - 1,535). The non-ocean products row is the memorandum row introduced in Table 3: it carries the inputs ocean industries buy from outside the ocean economy, and it is excluded from every ocean economy aggregate below.

Key aggregates derived from the SUT

From Tables 3 and 4, the following ocean economy aggregates are derived. Table 3.6.1 below summarises the key aggregates.

Every figure above is derivable from the two tables and from nothing else. That is the property to preserve when a compiler substitutes national data: an aggregate that cannot be recomputed from the published tables cannot be audited.

Reconciliation with TG-2.5. TG-2.5 Ocean Economy Structure Tables 3.1 and 3.1a report the same illustrative Country A on a fuller compilation that includes minor ocean industries omitted from this simplified SUT. The two presentations must be reconciled before either is cited, not used interchangeably.

Where the reconciliation holds, the aggregates feed the structural indicators in TG-2.5: ocean economy share of GDP (1,750/50,000 = 3.5%) and ocean economy investment rate (195/1,750 = 11.1%). The share-of-exports indicator is held back pending the reconciliation above.

The ocean economy SUT compiled in this example provides the ‘data foundation’ for multiple downstream applications across the Ocean Accounts Technical Guidance series:

3.8 Treatment of Coastal Tourism

Coastal tourism presents particular challenges for supply and use table compilation because tourism is defined from the demand side (activities of visitors) rather than the supply side (industrial classification). The Statistical Framework for Measuring the Sustainability of Tourism (SF-MST) provides guidance on integrating tourism statistics with economic and environmental accounts.

For ocean economy accounts, the recommended approach is set out in Table 3.7.1 below.

The SF-MST provides specific guidance on measuring tourism at sub-national levels, including destination-level measurement approaches that are directly applicable to coastal and marine tourism areas.

3.9 Integration with National SUTs

• Multiplier effects — the total economic impact of ocean industries, including direct, indirect, and induced effects throughout the economy
• Backward and forward linkages — the degree to which ocean industries are integrated with other sectors of the economy
• Embodied resource flows — the natural inputs (including marine resources) embodied in production throughout supply chains

These extended analyses support policy assessment and are relevant to the derivation of economic dependency indicators described in TG-2.2 Macro-level Dependencies.

For minimum institutional capacity, data infrastructure, and human skills requirements for compiling these accounts, see TG-0.8 Implementation Readiness Assessment. For guidance on adapting these methods to sub-national scales, see TG-3.11 Sub-National Ocean Accounts.