Structure and Function of the Ocean Economy

After working through this Circular, readers will be able to compile indicators characterising the structure and function of the ocean economy: sector composition by industry classification, sectoral shares of gross value added (GVA) and employment, growth and productivity indicators, net ocean GVA adjusted for resource depletion, and trade and investment patterns. The guidance also provides a step-by-step compilation procedure for extracting ocean economy sub-matrices from national supply and use tables and deriving structural indicators from them.

The guidance responds to high demand from governments seeking to characterise their ocean economies for national budget processes, economic planning, and international reporting—including reporting against Sustainable Development Goal 14 (Life Below Water), particularly target 14.7 on economic benefits from sustainable use of marine resources. These indicators build directly on the ocean economy thematic and extended accounts described in TG-3.3 Economic Activity Relevant to the Ocean and support applications in national budget processes addressed in TG-1.1 OA and National Budget Processes. The relationship between ocean economy structure and multilateral environmental agreement indicators, including SDG 14, is addressed further in TG-2.10 MEA Indicators.

Essential prerequisites:

• TG-0.1 General Introduction to Ocean Accounts — for the conceptual framework and key components of Ocean Accounts
• TG-3.3 Economic Activity Relevant to the Ocean — for the methodological framework for compiling ocean economy thematic and extended accounts, including industry classifications and supply and use tables

Helpful background:

• TG-0.2 Overview of Relevant Statistical Standards — for the international statistical standards underpinning ocean accounting, including the SNA 2025, SEEA, ISIC classification, and the methodological principles that govern thematic and extended accounts

3.1 Ocean Economy Structure Framework

The structure of the ocean economy describes how economic activity is distributed across different industries, products, and institutional sectors. A full structural analysis enables comparison of the ocean economy to the broader national economy, identification of dominant and emerging sectors, and assessment of concentration and diversification. Figure 2.5.1 illustrates the end-to-end data pipeline that produces these structural indicators, from raw statistical inputs through harmonisation and the supply-use table to the indicators reported in budget and MEA applications.

Ocean economy, marine economy, blue economy and sustainable ocean economy are not interchangeable, and the distinctions between them are set out in TG-1.0 Ocean Accounting and the Blue/Ocean Economy Section 3.2, together with the rule that a published account must disclose which term it uses. The indicators in this Circular measure the ocean economy as scoped in TG-3.3. They support blue economy reporting but do not by themselves constitute a blue economy account — see TG-1.0 Section 3.3 for what an account can and cannot certify.

Structural analysis of the ocean economy operates across four key dimensions:

Relationship to thematic and extended accounts

Structural indicators are derived from the ocean economy thematic and extended accounts described in TG-3.3 Economic Activity Relevant to the Ocean. For the thematic and extended accounts framework (SNA 2025 Chapter 38), see TG-0.2 Standards and Frameworks. The ocean economy accounts described in this Circular are thematic accounts in the SNA 2025 sense: they disaggregate and rearrange items within the integrated framework of national accounts. The supply and use tables (SUTs) compiled for the ocean economy provide the ‘data foundation’ for structural analysis. From balanced SUTs, the following can be derived:

Type 1 (thematic approach) selects value-added data for designated ocean industries directly from existing national accounts production data. Each ocean industry’s GVA is identified from the national production account and reported separately. This approach is lighter-weight, appropriate where fully balanced supply and use tables are not available, and lends itself to regional disaggregation more readily than the supply-use approach. Price adjustment uses a broad producer price index at the industry level. The core four indicators — gross output, GVA, employment, and GFCF — can be compiled from this approach.

Type 2 (supply-use framework) fully integrates ocean accounts within national input-output tables, measuring all inter-industry relationships at both product and industry level. This enables estimation of indirect and induced economic effects, reveals linkages between ocean industries and the rest of the economy, and requires product-level price deflators for volume measurement. This is the approach elaborated in §3.7 of this Circular.

Compilers should select the approach matched to their data infrastructure. Type 1 is a valid and publishable starting point; migration to Type 2 is recommended as the end-state when fully balanced SUTs are available.

Note on production versus expenditure approaches: Ocean accounts are built on the production (value-added) approach to GDP measurement. Whilst many countries publish their headline GDP figure using the expenditure approach (consumption + investment + government expenditure + net exports), the expenditure approach yields aggregate final demand totals and does not identify industry-level contributions. Both approaches yield the same GDP total under SNA 2025, but only the production approach enables identification of ocean economy industry composition. Compilers working within statistical systems that foreground expenditure-side figures should ensure that production-account data are accessed for ocean industry disaggregation.

This explicit mapping ensures that every indicator in this Circular can be traced back to a specific cell or aggregate in the ocean economy SUTs, providing a clear audit trail from accounts to indicators to policy applications.

3.2 Sector Composition Indicators

Sector composition indicators describe the relative importance of different industries within the ocean economy, enabling identification of dominant sectors, comparison with national industry structure, and tracking of structural change over time.

Ocean economy industries are classified using the International Standard Industrial Classification (ISIC). Following the categorisation in TG-3.3 Section 3.3, ocean industries are grouped as:

Core ocean-dependent industries (wholly ocean-related). Core ocean-dependent industries are identified at the division or class level depending on whether the entire division is ocean-related or only specific classes within a broader division:

• ISIC Division 03: Fishing and aquaculture
  • Class 0311: Marine fishing
  • Class 0321: Marine aquaculture
• ISIC Division 50: Water transport
  • Class 5011: Sea and coastal passenger water transport
  • Class 5012: Sea and coastal freight water transport
• ISIC Division 06: Extraction of crude petroleum and natural gas (offshore portion)
• ISIC Class 3510: Electric power generation, transmission and distribution (offshore wind, tidal, wave portion)

Ocean-related industries (partially ocean-related, requiring estimation of ocean share):

• ISIC Class 1020: Processing and preserving of fish, crustaceans and molluscs
• ISIC Class 3011: Building of ships and floating structures
• ISIC Class 3012: Building of pleasure and sporting boats
• ISIC Class 5222: Service activities incidental to water transportation
• ISIC Class 5224: Cargo handling (port cargo handling share)
• ISIC Class 5510: Short-term accommodation activities (coastal tourism share)
• ISIC Class 7210: Research and experimental development (marine research share)
• ISIC Class 8423: Public order and safety activities (coast guard, maritime enforcement share)
• ISIC Class 9319: Other sports activities (marine sports and recreation share)

This listing is illustrative and should be verified against the fuller classification in TG-3.3 Section 3.3, which provides the authoritative industry concordance for ocean economy accounts. Compilers should adapt the industry scope to their national circumstances and document the specific ISIC classes included. For offshore oil and gas extraction and offshore renewable energy, additional classification detail is provided in TG-3.10 Offshore Energy.

Scope decisions and international practice

There is no single agreed scope for the ocean economy, and national programmes legitimately differ. The 35-country review of ocean account definitions, the Portugal / United States / Norway comparison and the EU and OECD measurement programmes are in TG-1.0 Ocean Accounting and the Blue/Ocean Economy Sections 3.1 and 3.6; the industry scope a compiler actually applies is TG-3.3 Section 3.4. The consequence for the indicators below is that a share computed on one country’s scope is not comparable with the same share computed on another’s unless both disclose the scope, the tier and the ocean-ratio estimation level.

The following indicators characterise sector composition:

Output share by industry ${\text{Output share}}_i=\frac{{\text{Output}}_i}{\sum _j{\text{Output}}_j}\times 100$Output sharei​=∑j​Outputj​Outputi​​×100

where $i$i denotes an individual ocean industry and $j$j indexes all ocean industries.

GVA share by industry ${\text{GVA share}}_i=\frac{{\text{GVA}}_i}{\sum _j{\text{GVA}}_j}\times 100$GVA sharei​=∑j​GVAj​GVAi​​×100

This indicator reveals the relative contribution of each industry to total ocean economy value added. In the Ocean Accounts Framework (TG-0.1), the GDP contribution, industry output, and supply-use relationships measured through these structural indicators correspond to Edge E3 (monetary flows between assets and economic sectors), capturing the bidirectional monetary flows that characterise the ocean economy’s productive structure.

Employment share by industry ${\text{Employment share}}_i=\frac{{\text{Employment}}_i}{\sum _j{\text{Employment}}_j}\times 100$Employment sharei​=∑j​Employmentj​Employmenti​​×100

Recommended comparisons include:

1. Comparison to national economy — comparing ocean industry shares to their shares in the national economy reveals specialisation patterns

2. Comparison over time — tracking composition changes reveals structural transformation (e.g., growth of offshore energy relative to traditional fishing)

3. International comparison — comparing ocean economy structure across countries reveals different endowments and development patterns

Table 3.1 presents sector composition indicators 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 national GVA. All monetary values are expressed in millions of USD.

Table 3.1: Ocean economy sector composition (Country A, illustrative)

The HHI computed from the GVA shares in Table 3.1 is approximately 2,114 (= 32.0^2 + 24.0^2 + 18.0^2 + 10.0^2 + 7.0^2 + 4.0^2 + 5.0^2), indicating moderate concentration. Two sectors—coastal and marine tourism and offshore energy—together account for 56 per cent of ocean GVA, a pattern common in medium-income coastal states with established hydrocarbon production.

To make comparative analysis concrete, Table 3.1a presents a recommended format for comparing ocean economy structure against the national economy. This comparative presentation, adapted from the SF-MST approach to characterising tourism industries (SF-MST Table 3.3), enables identification of sectors in which the ocean economy is relatively more or less intensive than the national economy as a whole.

Table 3.1a: Ocean economy versus national economy structure (Country A, illustrative)

The data in Table 3.1a reveal that whilst the ocean economy accounts for 3.5 per cent of national GVA, it accounts for only 3.0 per cent of employment, implying slightly above-average labour productivity. The ocean economy’s share of exports (5.2 per cent) exceeds its share of national GVA, indicating an outward orientation driven by fish product exports and maritime transport services.

Table 3.1b maps the indicators derived from Tables 3.1 and 3.1a directly to the four-row budget presentation structure specified in TG-1.1 Section 3.3 (Table 1). This table provides the format in which ocean economy indicators should be presented in national budget submissions to demonstrate the sector’s contribution to the national economy.

Table 3.1b: Ocean economy contribution — budget presentation format (Country A, illustrative)

3.3 Growth and Productivity Indicators

Growth and productivity indicators measure the dynamic performance of the ocean economy, revealing whether it is expanding or contracting, whether growth is generating productivity improvements, and how ocean economy performance compares to the broader economy.

Compound annual growth rate (CAGR) — measures average annual growth over multiple periods: $\text{CAGR}={\left(\frac{X_T}{X_0}\right)}^{1/T}-1$CAGR=(X0​XT​​)1/T−1

where $X_0$X0​ is the value at the beginning of the period, $X_T$XT​ is the value at the end, and $T$T is the number of years between them.

Productivity measures the efficiency with which inputs are transformed into outputs. Two measures are particularly relevant for ocean economy analysis:

Labour productivity $\text{Labour productivity}=\frac{\text{GVA}}{\text{Employment}}$Labour productivity=EmploymentGVA​

This can be expressed per person employed, per job, or per hour worked. Labour productivity in ocean industries can be compared to national averages to assess relative efficiency.

Capital productivity (where capital stock data are available) $\text{Capital productivity}=\frac{\text{GVA}}{\text{Capital stock}}$Capital productivity=Capital stockGVA​

Capital stock data for ocean industries are often limited, particularly for industries such as offshore energy and maritime transport where assets are mobile and may be registered in multiple jurisdictions. Where direct capital stock data are unavailable, compilers may estimate capital stocks using the perpetual inventory method, applying asset-specific depreciation rates to historical investment series. The asset valuation methodology described in TG-3.1 Asset Accounts provides relevant guidance on produced capital valuation that can be adapted for ocean industries, particularly for vessels, port infrastructure, and offshore installations.

Multi-factor productivity growth requires more sophisticated analysis combining labour, capital, and intermediate inputs, typically using growth accounting or index number methods.

Ocean economy contribution to GDP growth

A particularly policy-relevant indicator is the contribution of the ocean economy to overall GDP growth:

$\text{Contribution to GDP growth}=\frac{\Delta \text{Ocean GVA}}{{\text{GDP}}_{t-1}}\times 100$Contribution to GDP growth=GDPt−1​ΔOcean GVA​×100

This measures the percentage point contribution of ocean economy growth to national GDP growth. This indicator is directly relevant for the budget justifications addressed in TG-1.1 OA and National Budget Processes and for demonstrating the economic importance of ocean management investment.

3.4 Net Ocean GVA

Gross measures of ocean economy value added do not account for the depletion of the marine natural resources on which many ocean industries depend. The SNA 2025 treats depletion of non-produced natural resources as a cost of production (SNA 2025 Chapter 13, para 13.26; see also the net value added formula in Chapter 15, para 15.137), and TG-1.1 Section 3.1 identifies net domestic product (NDP) as the conceptually preferred measure of economic growth. For the ocean economy, this has particular significance because fisheries, offshore minerals, and other extractive ocean industries draw down natural capital stocks.

Net ocean GVA is defined as:

• Depletion of fish stocks — the decline in the economic value of fish stock assets due to harvesting in excess of natural regeneration. Estimation methods are described in TG-3.1 Asset Accounts, drawing on stock assessment data from TG-6.7 Fisheries Accounting: Integrating Stock Assessment.
• Depletion of seabed minerals — the decline in the economic value of offshore mineral and hydrocarbon reserves due to extraction. Valuation follows the SNA 2025 treatment of subsoil assets (Chapter 15, rows 22—23 of the Use Table).

Table 3.2 presents employment structure indicators for Country A, populated with synthetic data reflecting typical patterns observed in medium-income coastal states.

Table 3.2: Ocean economy employment structure (Country A, illustrative)

The Total ocean column covers all seven industries in Table 3.1. Marine renewable energy (6,000 persons) and other ocean industries (9,000 persons) are not shown as columns, so the six columns sum to 285,000 persons and 238,500 FTE; the remaining 15,000 persons and 11,500 FTE belong to those two industries. Marine fishing and aquaculture together make up marine living resources in Table 3.1 (54,000 persons).

Ocean economy imports — imports of ocean-characteristic products, including:

• Fishing vessels and equipment
• Maritime transport services (freight payments)
• Offshore drilling equipment
• Imported fish for processing

Trade balance for ocean economy $\text{Ocean trade balance}=\text{Ocean exports}-\text{Ocean imports}$Ocean trade balance=Ocean exports−Ocean imports

Revealed comparative advantage — indicates whether a country specialises in ocean products relative to its overall trade pattern: ${\text{RCA}}_i=\frac{\left(X_i/X\right)}{\left(X_i^{world}/X^{world}\right)}$RCAi​=(Xiworld​/Xworld)(Xi​/X)​

where $X_i$Xi​ is exports of ocean product $i$i, $X$X is total exports, $X_i^{world}$Xiworld​ is world exports of ocean product $i$i, and $X^{world}$Xworld is total world exports. An RCA > 1 indicates comparative advantage.

Maritime transport services trade requires careful treatment due to the distinction between resident and non-resident operators. The spatial treatment of economic activities within the Exclusive Economic Zone is addressed in TG-3.3 Section 3.1. The Balance of Payments Manual (BPM6; BPM7, forthcoming) provides detailed guidance on recording maritime transport services in the current account, including the allocation of freight charges between importing and exporting economies and the treatment of services provided by non-resident carriers. Compilers should ensure that trade in maritime transport services is recorded consistently between the ocean economy accounts and the balance of payments.

Gross fixed capital formation (GFCF) in ocean industries

Ocean economy investment includes:

• Vessels (fishing boats, cargo ships, cruise ships)
• Port infrastructure (harbours, terminals, cargo handling equipment)
• Offshore platforms and installations
• Aquaculture facilities
• Coastal tourism infrastructure

Investment rate $\text{Investment rate}=\frac{\text{Ocean GFCF}}{\text{Ocean GVA}}\times 100$Investment rate=Ocean GVAOcean GFCF​×100

Investment share $\text{Investment share}=\frac{\text{Ocean GFCF}}{\text{Total national GFCF}}\times 100$Investment share=Total national GFCFOcean GFCF​×100

This reveals the ocean economy’s share of national capital formation.

Beyond conventional GFCF, the investment dimension of the ocean economy increasingly includes sustainable ocean finance instruments such as blue bonds, blue loans, and blue equity investments. These instruments channel capital towards ocean-related activities that meet defined environmental sustainability criteria. Whilst sustainable finance flows are not recorded as GFCF in the national accounts (they represent financial transactions rather than acquisition of produced assets), their scale and growth constitute an important structural characteristic of the ocean economy’s financing landscape. The methodology for measuring sustainable ocean finance, including classification criteria, data sources, and indicator definitions, is addressed in TG-2.6 Ocean Investment Section 3.4.

Table 3.3 presents trade and investment indicators for Country A.

Table 3.3: Ocean economy trade and investment (Country A, illustrative)

Government expenditure on ocean-related functions

Government expenditure on ocean-related activities can be identified using the Classification of the Functions of Government (COFOG). Table 3.4 maps specific COFOG classes to ocean-related government functions, adapted from the SF-MST approach to identifying tourism-related government functions (SF-MST Table 3.9).

Table 3.4: COFOG classes relevant to ocean economy functions

This mapping supports analysis of public investment in ocean management addressed in TG-1.1 OA and National Budget Processes.

The procedure below is adapted from the SNA 2025 treatment of supply and use tables (Chapter 15, paras 15.9, 15.130—15.139) and draws on the analogous approach developed for tourism in the SF-MST (paras 2.30—2.31, 3.27—3.28).

Steps 1—5 are TG-3.3’s. Identifying ocean industries through the ISIC concordance, extracting the sub-matrices from the balanced national SUTs, determining the ocean ratio for each partially ocean-related industry, computing Ocean Economy Direct GVA and adjusting for taxes less subsidies on products to reach Ocean Economy Direct GDP are all specified in TG-3.3 Economic Activity Relevant to the Ocean Sections 3.4 and 3.5. They are not restated here.

What a compiler needs to check before deriving the indicators below is that the extract carries: GVA and employment by industry rather than as an ocean-economy total, the ocean ratio and its estimation level recorded per industry, and a consistent employment measure across numerator and denominator. Composition, productivity and structure indicators all require the disaggregation; the ratios cannot be recovered from a single total.

Step 6: Derive indicators from the ocean economy SUT extract. Using the ocean economy sub-matrices and the ocean economy ratios, compute the full set of structural indicators described in Sections 3.2 through 3.6 of this Circular: sector composition indicators (GVA shares, employment shares, HHI), growth and productivity indicators, net GVA, employment structure, and trade and investment indicators.

Raw data are collected through surveys (TG-4.2) and administrative records (TG-4.3), harmonised (TG-4.6), and compiled into ocean economy thematic accounts (TG-3.3). The indicator formulas in this Circular are then applied to produce structural indicators, which are formatted for policy application in national budget processes (TG-1.1) and international reporting (TG-2.10).

Key data sources include:

Publication scope norm. Compilers should publish only what their supply and use tables can support. The starting set is the core four indicators — gross output, GVA, employment, and GFCF — compiled directly from the SUTs; trade in ocean-characteristic products is added only where it can be balanced against the SUTs. Extension to additional indicators is appropriate only after supplementary sources have been properly reconciled with national accounts data. Where partials are used, the underlying data sources and allocation rules should be published alongside indicator results.

Metadata requirements. Ocean accounts metadata should document at minimum: sector and industry coverage, the economic concepts applied (including whether a Type 1 or Type 2 approach was used), time period, geographic definition and inland boundary decisions, industrial classification system, data collection method per industry (survey, administrative data, or expert judgement), and any confidentiality suppressions applied. Because ocean account scope and geographic boundary definitions legitimately differ across countries, metadata is the primary mechanism enabling valid cross-country comparisons.

For time series analysis and international comparison:

• Use consistent industry and product classifications
• Apply consistent valuation principles (basic prices versus purchasers’ prices)
• Document changes in methodology that affect comparability
• Use appropriate exchange rates for international comparison

The standing international comparators — the European Commission’s annual EU Blue Economy Report and the OECD’s ocean economy measurement work — are described in TG-1.0 Section 3.6, and the reader-side checklist for interrogating a published figure is TG-1.0 Section 3.7.

Authors: [To be confirmed]

Reviewers: [To be confirmed]