General Introduction to Ocean Accounts

1. Outcome

This Circular provides a foundational understanding of Ocean Accounts as a structured and standardised approach to measuring and managing progress toward sustainable ocean development. Readers will gain clarity on the key characteristics, components, and applications of Ocean Accounts, understand how they integrate environmental, economic, and social information, and learn how Ocean Accounts support evidence-based decision-making for sustainable ocean management. The Circular serves as an entry point to the broader Technical Guidance on Ocean Accounting, which provides detailed methodologies and instructions for account compilers, data providers, and end-users.

2. Requirements

None--this Circular introduces the Technical Guidance on Ocean Accounts for Sustainable Ocean Development as a whole. Other Circulars elaborate on the general overview provided in this Circular.

3. Guidance Material

3.1 Sustainable development of the ocean

Sustainable development is fundamentally about "meeting the needs of the present without compromising the ability of future generations to meet their own needs"^[1]. This core principle has evolved through a long series of international frameworks including Agenda 21, the Millennium Development Goals, and most recently the 2030 Agenda for Sustainable Development with its 17 Goals (SDGs) and 169 associated Targets.

Sustainable ocean development specifically applies these principles, goals and targets to marine and coastal environments, which cover 71% of Earth's surface, hold 97% of its water, and support 80% of its life forms^[2]. SDG 14 "Life Below Water" directly addresses ocean sustainability, though the ocean contributes to numerous other SDGs related to poverty alleviation, food security, climate action, and economic growth^[3].

From an operational perspective, sustainable development requires maintaining or enhancing the assets (capital) that are necessary for long-term development. These include not only produced and financial capital but critically, natural capital--which the 2025 SNA defines as the combination of natural resources (such as mineral and energy resources, biological resources, and water resources, recognised within the integrated framework of national accounts) and ecosystem assets (spatially defined areas of ecosystems, measured through SEEA Ecosystem Accounting)^[4][5][6]. The 2025 SNA formally locates natural capital within a broader multiple-capitals framework for assessing wellbeing and sustainability, alongside produced capital, human capital, and social capital (Chapters 2, 34 and 35)^[6:1].

The ocean contains and supports a wide range of natural capital assets: individual environmental assets located in the ocean (such as aquatic resources and seabed mineral and energy resources, as defined in the SEEA Central Framework), marine and coastal ecosystem assets (as defined in SEEA Ecosystem Accounting), and produced assets supporting ocean economic activity (as defined in the SNA)^[7][8]. These assets provide services from fisheries production and coastal protection to carbon sequestration and cultural benefits. It should be noted, however, that the ocean water body itself is not treated as an environmental asset in the SEEA framework, because the stock of water is too large to be meaningful for analytical purposes (SEEA CF para 2.102)^[7:1]. This exclusion does not limit the measurement of individual assets within the ocean, such as fish stocks and seabed minerals.

Sustainable ocean development entails three interconnected objectives: (1) advancing ocean-based economic activities that provide sustainable livelihoods, (2) ensuring equitable distribution of benefits across society, and (3) conserving and enhancing marine ecosystems and their ecological processes^[9]. This balanced approach recognizes the ocean as a complex socio-ecological system where environmental health underpins both economic productivity and social wellbeing.

3.2 Information requirements for sustainable development decision-making

Effective decision-making for sustainable ocean development requires comprehensive information systems that integrate environmental, economic, and social domains. Traditional economic indicators like Gross Domestic Product (GDP), while valuable for measuring economic activity, fail to capture environmental depletion, equity considerations, or important values that are not traded in markets^[10]. The limitations of GDP as a measure of societal wellbeing and sustainable development have led to numerous initiatives focused on developing metrics "Beyond GDP"^[11].

Efforts to measure progress Beyond GDP are also now recognized in a range of decisions of international organisations, and intergovernmental commitments. For example SDG 15.9 and the Montreal-Kunming Global Biodiversity Framework both call for the integration of ecosystem and biodiversity values into national and local planning processes, poverty alleviation strategies and accounts. SDG 17.19 calls for the development of measures of progress to complement GDP, and statistical capacity building to that end. Concerning ocean accounts specifically, Decisions 15/24 (2022) and 16/1 (2024) of the Convention on Biological Diversity States Parties calls on countries to implement ocean accounts as a basis for conservation and sustainable management of marine resources and islands.

The information needed for sustainable ocean development decisions must address three critical questions^[12]:

1. What is the current economic output or production from ocean-related activities?
2. What benefits (and disbenefits) do people and communities derive from the ocean and how are these distributed?
3. Is ocean development sustainable over time?

Answering these questions requires multiple indicators and knowledge spanning different domains. For example: ocean production indicators measure economic output from ocean activities. Ocean income indicators assess the benefits people receive from the ocean, including physical measures of ecosystem services and monetary measures that can be disaggregated across population segments. Changes in ocean balance sheets provide sustainability indicators by tracking changes in natural capital assets over time.

Beyond these headline indicators, decision-makers need information on specific relationships between human activities and the marine environment, including:

• Dependencies of economic sectors on marine ecosystem services
• Impacts of economic activities on marine ecosystem assets
• Distribution of benefits across different social groups
• Effectiveness of governance arrangements in managing human-ocean interactions
• Resilience of marine systems to natural and anthropogenic pressures

These information requirements demand structured approaches to data integration, processing, and presentation that can handle complex, multi-dimensional relationships while providing clear signals to guide policy choices^[13].

3.3 Definition and scope of Ocean Accounts

Ocean Accounts constitute a structured framework for compiling and integrating data about marine and coastal environments and their relationship with human societies and economies. They represent a statistical framework for measuring the ocean, its importance to people, and what people are doing to change it. Ocean Accounts are distinguished from other ocean-related information compilations by three key characteristics:

1. Organization according to the Ocean Accounts Framework presented in this Technical Guidance, which enhances consistency, comparability, and coherence across social, environmental, and economic domains
2. Compatibility with international statistical standards, in particular the System of National Accounts (SNA) and System of Environmental-Economic Accounting (SEEA)
3. Adherence to principles of official statistics, ensuring information is fit-for-purpose for policy decision-making^[14]

The framework covers marine and coastal areas within national jurisdictions (territorial waters, exclusive economic zones, continental shelves) and can be applied to particular areas within these zones (e.g., bays, protected areas). It is also applicable to activities functionally connected with but spatially separate from the ocean (e.g. nutrient pollution), and to areas beyond national jurisdiction though with added conceptual challenges.

Ocean Accounts are not merely collections of ocean-related statistics. Rather, they provide a coherent structure that:

• Applies accounting principles to ensure completeness and internal consistency
• Uses standardized classifications, definitions, and measurement approaches
• Enables spatial and temporal comparisons
• Facilitates the production of indicators that track progress toward policy objectives
• Supports integrated analysis of tradeoffs and synergies across different goals

While Ocean Accounts can include economic valuation of some ocean assets and services, they do not aim to determine a single "total value" of the ocean, which would be both conceptually problematic and practically impossible^[15]. Instead, they provide a framework for understanding the many ways oceans contribute to human wellbeing and for tracking changes in these contributions over time.

3.4 Functional components of Ocean Accounts

Ocean Accounts function as an information system that transforms diverse data inputs into standardized, decision-relevant outputs through several interconnected processes, which are illustrated summarily in Figure 1 below:

Figure 1: Summary functional structure of Ocean Accounts

┌─────────────────────────────────────────────────────────────────────┐
│  4. INDICATORS AND REPORTS                                          │
│     For multiple decision processes                                 │
├─────────────────────────────────────────────────────────────────────┤
│  3. STANDARDISED ACCOUNTS                                           │
│     Tables, other data structures and interfaces                    │
├─────────────────────────────────────────────────────────────────────┤
│  2. DATA SHARING AND VALIDATION                                     │
│     Applying statistical principles and standards                   │
├─────────────────────────────────────────────────────────────────────┤
│  1. DATA SOURCES                                                    │
│     Social, Economic, Environmental, Customary                      │
└─────────────────────────────────────────────────────────────────────┘

The construction of Ocean Accounts begins with data collection and compilation from numerous sources: government agencies, research institutions, industry bodies, citizen science programs, and indigenous knowledge systems. These data span environmental monitoring, economic statistics, social surveys, governance information, geospatial observations, customary knowledge, and many others^[16]. A critical step is aligning these heterogeneous datasets to common spatial boundaries, classifications, and accounting periods, through data sharing and validation processes that apply the relevant international statistical principles and standards (in particular the SNA and SEEA).

Raw data are then organized into standardized accounting tables or other data structures (e.g. non-relational JSON objects) in accordance with the Ocean Accounts Framework. These structures make several conceptual distinctions, in particular between:

• Stocks of assets: with levels measured or valued at a point in time (for example fish biomass, coral reefs, or coastal infrastructure).
• Flows of goods, (dis)services or activities: physical or monetary transfers, measured or valued at a point in time, between assets and/or social or economic sectors (for example fish harvest, coastal protection from mangrove forests, pollution of the environment by economic activity).

From these tables, analysts or automated systems derive indicators and visualizations that condense complex information into decision-relevant metrics. Modern technology enables the creation of interactive dashboards that allow users to explore relationships between variables, compare scenarios, and monitor trends over time^[17]. These outputs support a wide range of decision contexts including planning, investment, regulation, monitoring and evaluation, and reporting.

3.5 Conceptual components of the Ocean Accounts Framework

The Ocean Accounts Framework comprises several sub-component accounts that are together designed to provide a coherent and comprehensive view of ocean-society-economy interactions, as illustrated in Figure 2 below. The Framework distinguishes between stocks (measured in terms of their status, extent and/or condition) and flows (measurements of supply, use or activity) concerning the economy, society beyond the scope of the economy (defined by the SNA 2025 production boundary) and the environment beyond the scope of society. Recognising that in many countries, traditional knowledge systems do not make clear distinctions between people and nature, the Framework also supports integrated accounting for qualitative and quantitative data drawn from multiple knowledge systems^[18].

Figure 2: Key conceptual components of the Ocean Accounts Framework

┌────────────────────────────────────────────────────────────────────────────────┐
│                                                                                │
│  ┌──────────────────┐  ┌──────────────────┐  ┌──────────────────┐             │
│  │     ECONOMY      │  │     SOCIETY      │  │   ENVIRONMENT    │             │
│  └──────────────────┘  └──────────────────┘  └──────────────────┘             │
│                                                                                │
│  ╔══════════════════════════════════════════════════════════════════════════╗ │
│  ║ FLOWS                                                                     ║ │
│  ║                                                                           ║ │
│  ║  ┌────────────┐      ┌────────────┐      ┌────────────┐                  ║ │
│  ║  │ Flows      │ ←──→ │ Flows and  │ ←──→ │ Flows and  │                  ║ │
│  ║  │ within     │      │ activities │      │ interactions│                  ║ │
│  ║  │ economy    │      │ within     │      │ within      │                  ║ │
│  ║  │ (SNA)      │      │ society    │      │ environment │                  ║ │
│  ║  └────────────┘      └────────────┘      └────────────┘                  ║ │
│  ║         ↑                  ↑                   ↑                          ║ │
│  ║         │                  │                   │                          ║ │
│  ║         ├──────────────────┴───────────────────┤                          ║ │
│  ║         │    Cross-domain flows:               │                          ║ │
│  ║         │    • Pollution/residuals             │                          ║ │
│  ║         │    • Monetary flows                  │                          ║ │
│  ║         │    • Social contributions            │                          ║ │
│  ║         │    • Ecosystem service flows         │                          ║ │
│  ║         └──────────────────────────────────────┘                          ║ │
│  ╚══════════════════════════════════════════════════════════════════════════╝ │
│                                                                                │
│  ╔══════════════════════════════════════════════════════════════════════════╗ │
│  ║ STOCKS                                                                    ║ │
│  ║                                                                           ║ │
│  ║  ┌────────────┐      ┌────────────┐      ┌────────────┐                  ║ │
│  ║  │ Produced & │      │ Social     │      │ Environmental│                 ║ │
│  ║  │ financial  │      │ assets and │      │ assets and  │                  ║ │
│  ║  │ assets     │      │ conditions │      │ conditions  │                  ║ │
│  ║  └────────────┘      └────────────┘      └────────────┘                  ║ │
│  ╚══════════════════════════════════════════════════════════════════════════╝ │
│                                                                                │
└────────────────────────────────────────────────────────────────────────────────┘

The sub-component accounts illustrated in Figure 2 are described in detail in other Technical Guidance Circulars, and can be summarised for the present purposes as follows:

Spatial data framework

The Framework employs a spatially explicit approach with Basic Spatial Units (BSUs) as the foundation. These units may be differentiated into terrestrial, coastal, and marine BSUs, establishing connections between terrestrial activities that impact the ocean, coastal transition zones, and marine environments. Depth layers within BSUs enable a three-dimensional perspective that accommodates the complex spatial nature of ocean systems.

Environmental assets

The Framework accommodates both individual environmental assets (as defined in the SEEA Central Framework) and ecosystem assets (as defined in SEEA Ecosystem Accounting). Individual environmental assets in the ocean domain can be classified according to the 2025 SNA's five categories of natural resources^[5:1][6:2]:

1. Land (including coastal land and the seabed)
2. Mineral and energy resources (including seabed minerals and offshore energy resources, as well as renewable energy resources such as offshore wind and tidal energy, AN322)
3. Biological resources (including aquatic resources such as fish stocks)
4. Water resources
5. Other natural resources

These assets provide inputs to economic activities and are accounted for within the integrated framework of national accounts. Ecosystem assets are conceptualized as spatially-defined areas containing combinations of biotic and abiotic components that function together as a unit, potentially supplying a range of ecosystem services. For the ocean domain, these may include coral reefs, seagrass meadows, mangroves, coastal wetlands, pelagic and benthic marine ecosystems, and other categories recognised in the Global Ecosystem Typology^[19].

The Framework enables tracking of both the extent and condition of these assets. Ecosystem condition is measured using the SEEA EA Ecosystem Condition Typology (ECT), which organises condition variables into three groups and six classes^[8:1][20]:

• Abiotic characteristics:
  • Physical state (e.g., sea surface temperature, current patterns, bathymetry)
  • Chemical state (e.g., ocean pH, dissolved oxygen, nutrient concentrations)
• Biotic characteristics:
  • Compositional state (e.g., species diversity of reef fish assemblages, phytoplankton community composition)
  • Structural state (e.g., coral cover, seagrass canopy height, mangrove stem density)
  • Functional state (e.g., primary productivity, fish recruitment rates, decomposition rates)
• Landscape/seascape characteristics: (e.g., spatial configuration of habitat patches, connectivity between reef systems, fragmentation of coastal wetlands)

Condition is measured relative to a reference condition that reflects, where possible, the natural or undegraded state of the ecosystem (SEEA EA para 5.69)^[8:2].

An important distinction applies to aquatic biological resources. Aquaculture production (cultivated biological resources) falls within the SNA production boundary: the growth of organisms in aquaculture facilities is treated as a process of production, and these resources are classified as produced assets. In contrast, wild-capture fisheries target natural biological resources that are outside the production boundary until harvest, and are subject to depletion accounting. This distinction, elaborated in SEEA CF Section 5.9^[7:2], has fundamental implications for how these resources are recorded in ocean accounts--including whether changes in stock are treated as changes in produced capital or as depletion of natural resources.

Social assets and conditions

The Framework provides structures to incorporate social dimensions affecting and affected by ocean environments and economies. This can include measures of wellbeing, vulnerability, and resilience in coastal communities--such as poverty rates, food security, and disaster risk exposure. Social indicators may be disaggregated by demographic factors to facilitate equity analyses. Governance accounts can complement these metrics by documenting institutional arrangements, legal frameworks, customary practices, and policy instruments that shape human-ocean interactions.

Produced and financial assets

The Framework enables the inclusion of stocks of built capital (infrastructure, vessels, equipment) and financial capital (investments, funds, securities) relevant to ocean activities. These assets, traditionally captured in the SNA's balance sheets, can be adapted to highlight their ocean-specific dimensions and spatial distribution.

Flows within the economy

The Framework enables the representation of economic transactions related to ocean activities as defined in the SNA, including production, consumption, income, and capital flows. Physical flows of natural resource inputs and residuals between the environment and the economy are structured using Physical Supply and Use Tables (PSUTs), the established accounting framework in the SEEA Central Framework (Chapter III) that extends the monetary supply and use structure of the SNA to physical units^[7:3].

Flows and activities within society beyond the SNA

The Framework allows for the inclusion of important social activities that fall outside the SNA production boundary but significantly impact ocean sustainability. These may include unpaid household labor such as subsistence fishing, food preparation from ocean resources, and customary marine stewardship activities.

Flows and interactions within the environment

The Framework provides structures to represent ecological processes and interactions occurring within marine environments that maintain ecosystem functioning. These can include biogeochemical cycles (carbon, nitrogen, phosphorus), energy flows through food webs, species migrations, larval dispersal, and other dynamic processes that connect different ecosystems.

Flows of pollution, waste and other residuals

The Framework systematically enables recording of human-generated outputs that affect marine environments, including point-source pollutants, diffuse pollutants, solid waste, noise, heat, and other emissions.

Monetary flows between assets and economic sectors

The Framework allows for tracking monetary transactions associated with produced and financial ocean-related assets within the SNA production boundary.

Contributions of social conditions to activities

The Framework facilitates capturing the bidirectional relationship between social conditions and various activities in both social and economic domains.

Supply and use of ecosystem services

The Framework enables capturing the flow of services from marine and coastal ecosystems directly benefiting human wellbeing and economic activity. These may include provisioning services (such as wild fish and other natural aquatic biomass provisioning), regulating and maintenance services (such as coastal protection, global climate regulation through carbon sequestration and storage, and water purification), and cultural services (such as recreation, visual amenity, and spiritual, artistic and symbolic services)^[8:3].

3.6 Relationship to other standards and approaches

Ocean Accounts build upon and interact with several established international standards and emerging approaches:

System of National Accounts (SNA)

The System of National Accounts (SNA)^[5:2] provides the foundational structure for measuring economic activity. The 2025 SNA, adopted by the United Nations Statistical Commission in March 2025, represents a significant advance over the 2008 SNA^[21] in its treatment of environmental and sustainability dimensions. Notably, the 2025 SNA now treats the depletion of natural resources as a cost of production alongside depreciation, giving more emphasis to net income measures such as Net Domestic Product (NDP) as the conceptually preferred measure of economic growth (Annex 4, para A4.59). The 2025 SNA also formally defines natural capital, introduces new chapters on wellbeing and sustainability measurement (Chapters 34-35), and explicitly identifies ocean accounting as an application of its thematic accounting framework (para 35.63)^[6:3].

System of Environmental-Economic Accounting (SEEA)

The System of Environmental-Economic Accounting (SEEA) includes two complementary standards: the SEEA Central Framework (SEEA-CF)^[7:4] and SEEA Ecosystem Accounting (SEEA-EA)^[8:4]. SEEA-CF provides methodology for measuring individual environmental assets (e.g., fish stocks, minerals) and their flows into the economy, structured through Physical Supply and Use Tables and asset accounts. SEEA-EA focuses on ecosystem accounting, including ecosystem extent, condition, and services. Ocean Accounts adapt these approaches specifically for the marine domain, addressing challenges such as three-dimensional ecosystem delineation and fluid boundaries^[22].

Ocean Economy Satellite Accounts

Ocean Economy Satellite Accounts are specialized economic accounts that disaggregate and measure ocean-related economic activities. These complement traditional national accounts by providing greater detail on maritime sectors that are often hidden within broader classifications^[23].

Natural Capital Accounting (NCA)

Natural Capital Accounting (NCA) broadly refers to approaches that measure natural assets and their contributions to the economy. Ocean Accounts represent a specific application of NCA principles to the marine domain, with particular attention to spatial detail and ocean-specific challenges^[24].

Corporate disclosure frameworks

Corporate disclosure frameworks like the Task Force on Climate-related Financial Disclosures (TCFD) and emerging frameworks for nature-related financial disclosures focus on enterprise-level reporting. While Ocean Accounts primarily support public policy at national and subnational scales, the concepts and data can inform corporate reporting on ocean dependencies and impacts^[25].

Marine Spatial Planning (MSP)

Marine Spatial Planning (MSP) frameworks organize the spatial allocation of ocean activities. Ocean Accounts can provide standardized data inputs to MSP processes and help evaluate outcomes of spatial planning decisions over time^[26].

3.7 Data quality and uncertainty

The compilation of ocean accounts involves integrating data from diverse sources with varying levels of quality, coverage, and precision. The SEEA EA identifies six dimensions of data quality relevant to environmental-economic accounting: relevance, timeliness, accuracy, coherence, interpretability, and accessibility, together with the quality of the institutional environment in which the data are compiled (SEEA EA para 2.86)^[8:5].

In addition, four categories of uncertainty are particularly pertinent to ecosystem accounting and apply directly to ocean accounts:

1. Uncertainty related to physical measurement of ecosystem services and ecosystem assets
2. Uncertainty in the valuation of ecosystem services and ecosystem assets
3. Uncertainty related to the dynamics of ecosystems and changes in flows
4. Uncertainty regarding future prices and values (SEEA EA para 2.90)^[8:6]

It is important that all accounting work document the scope of measurement, the definitions applied, the methods used, and the assumptions made (SEEA EA para 2.95). Circular 0.7 addresses quality assurance and quality control procedures for ocean accounts in detail.

3.8 Implementation approaches and starting points

Ocean Accounts implementation can follow diverse pathways tailored to national contexts, policy priorities, and resource constraints. Countries typically adopt modular approaches, building accounts progressively rather than attempting comprehensive implementation from the outset.

Common entry points include:

• Thematic focus: Marine protected area management, sustainable fisheries, coastal tourism development, marine pollution reduction, climate change adaptation, blue economy development strategies^[27]

• Geographic scope: National level (whole exclusive economic zone), subnational regions, specific ecosystems (coral reefs, mangroves), marine protected areas, areas of high economic significance or environmental vulnerability

• Existing data availability: National statistical compilations, environmental monitoring programs, economic surveys, marine spatial data infrastructures, research programs, administrative datasets^[28]

• Institutional arrangements: National statistics office-led, environment agency-led, multi-agency collaborative efforts, research institution partnerships

The modular, adaptive nature of Ocean Accounts allows for a "learn-by-doing" approach. Initial pilot studies often focus on feasibility assessment and capability development before scaling to more comprehensive implementation. Countries with limited resources may begin with rapid assessments using global datasets before developing more detailed national accounts^[29].

4. Acknowledgements

This Circular has been approved for public circulation and comment by the GOAP Technical Experts Group in accordance with the Circular Publication Procedure.

Authors: Ben Milligan (University of New South Wales), Teerapong Praphotjanaporn (UN Economic and Social Commission for Asia and the Pacific). The authors acknowledge prior content adapted from the collective work of the authors of the Version 1.0 Technical Guidance developed by member institutions of the Global Ocean Accounts Partnership.

Reviewers: Emily Mckenzie (Taskforce for Nature-related Financial Disclosures), Crystal Bradley (Australian National University), Firdaus Agung (Government of Indonesia), Carl Obst (IDEEA Group).

5. References