OA and Fisheries Management

1. Outcome

This Circular provides guidance on using Ocean Accounts to inform fisheries management decisions. Ocean Accounts provide a structured framework for integrating fisheries stock assessment data with economic performance indicators and sustainability metrics, enabling evidence-based decision-making that balances extraction with ecosystem health.

The guidance addresses the practical integration of biological stock assessment data with asset accounts, approaches to valuing fish stocks, methods for deriving economic performance indicators for the fisheries sector, and the calculation of sustainability indicators aligned with international targets including SDG 14.4^[1].

Decision use cases: Ocean Accounts for fisheries support four critical management functions. First, quota setting using asset account depletion data: physical asset accounts tracking biomass, natural growth, and extraction enable managers to assess whether current catch levels exceed sustainable yield, providing an objective basis for setting Total Allowable Catch (TAC) quotas. Second, MSY verification: comparing stock biomass estimates to BMSY benchmarks derived from stock assessments enables verification that fisheries management plans are achieving their stated objectives of maintaining stocks at levels capable of producing maximum sustainable yield. Third, subsidy reform using flow accounts: flow accounts for fisheries subsidies linked to stock status indicators reveal whether government support is contributing to overcapacity and overfishing or promoting sustainable practices, informing policy design aligned with SDG 14.6. Fourth, SDG 14.4 reporting: asset accounts provide the direct inputs for SDG indicator 14.4.1 (proportion of fish stocks within biologically sustainable levels), ensuring that international reporting is grounded in comprehensive national accounting data. These use cases connect directly to the policy frameworks described in TG-1.1 OA and National Budget Processes, where fisheries depletion costs are integrated into natural capital budgeting.

Downward connections to accounts, indicators, and data: The policy decisions supported by this Circular depend on three foundational accounting structures. Fish stock asset accounts (see TG-3.1 Asset Accounts) track biomass, natural growth, extraction, and depletion in physical and monetary terms, providing the data infrastructure for sustainable yield management. Flow accounts for fish harvest (see TG-3.2 Flows from Environment to Economy) record gross catch, landings, and discards, enabling catch statistics to be reconciled with stock assessments and supporting analysis of fishing impacts across the supply chain. Ecosystem condition indicators (see TG-2.1 Biophysical Indicators) for fish nursery habitats such as mangroves, seagrass meadows, and estuaries link habitat health to fisheries productivity, demonstrating how ecosystem degradation affects the regenerative capacity of fish stocks. These three layers--asset stocks, flow accounts, and condition indicators--form an integrated information system enabling Ocean Accounts to translate biological stock assessment science into policy-relevant insights.

2. Requirements

• TG-0.1 General Introduction

Related Circulars:

• TG-3.1 Asset Accounts—General methodology for physical and monetary asset accounts
• TG-3.2 Flows from Environment to Economy—Treatment of fish harvest as natural resource input
• TG-3.9 Aquaculture—Distinguishing cultivated from natural aquatic resources
• TG-6.7 Fisheries Accounting: Integrating Stock Assessment—Detailed thematic methodology for linking stock assessment to accounts

3. Guidance Material

3.1 Fisheries in the Ocean Accounting Framework

3.1.1 Classification of Aquatic Resources

Aquatic resources are classified within the SEEA Central Framework as one of five categories of natural resources that comprise natural capital^[2]. The classification distinguishes between:

Cultivated aquatic resources include all aquatic organisms produced within aquaculture facilities where there is active management over growth and regeneration. Farming implies intervention in the rearing process to enhance production, such as regular stocking, feeding, and protection from predators, as well as individual or corporate ownership of the stock being cultivated^[3]. Cultivated aquatic resources are further divided into:

• Resources held for harvest (treated as inventories)
• Breeding stock (treated as fixed assets)

For detailed guidance on aquaculture accounting, see TG-3.9 Aquaculture.

Natural aquatic resources comprise wild fish stocks, crustaceans, molluscs, marine mammals, and other aquatic organisms that are harvested through capture fishing operations where growth and regeneration occur naturally without direct management by institutional units^[4]. Natural aquatic resources are considered natural biological resources and are classified as non-produced non-financial assets.

This distinction determines the accounting treatment. The growth of cultivated aquatic resources in aquaculture facilities is treated as a process of production that falls within the SNA production boundary. In contrast, wild capture fisheries target natural biological resources that are outside the production boundary until harvest, and are therefore subject to depletion accounting when extraction exceeds sustainable yield^[5]. The harvest of wild fish represents a flow from the environment to the economy, as described in TG-3.2 Flows from Environment to Economy.

3.1.2 Spatial Scope and Jurisdictional Boundaries

For accounting purposes, aquatic resources are attributed to a country based on their location within that country's exclusive economic zone (EEZ) throughout their life cycles, covering both marine and inland waters^[6]. The legal framework for defining these boundaries is provided by the United Nations Convention on the Law of the Sea (UNCLOS), which establishes that coastal States have sovereign rights over the natural resources of their EEZ extending up to 200 nautical miles from their baselines^[7].

Migrating and straddling fish stocks present particular measurement challenges. Such stocks are considered to belong to a country during the period when they inhabit its EEZ. When exploitation control has been established through international agreements that define a country's access rights to shared resources, that portion of the stock can be attributed to the country^[8]. The Agreement for the Implementation of the Provisions of UNCLOS relating to the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks and the FAO Code of Conduct for Responsible Fisheries provide the legal framework for managing these shared resources^[9].

Where a stock migrates in and out of the EEZ within the accounting year, biomass attribution should follow the country's agreed RFMO allocation share where a formal allocation exists. Where no formal allocation exists, the preferred default is to attribute biomass in proportion to the estimated stock fraction present within the EEZ at the mid-year survey date. Compilers should document the method chosen in account metadata and flag the risk of double-counting when multiple countries account for the same stock. Adjustments to allocation shares over time should be recorded as reclassifications in the asset account rather than as physical changes^[10].

Regional Fisheries Management Organizations (RFMOs) play a central role in coordinating the management of shared and straddling stocks and can serve as important data sources for compiling national accounts. In the Asia-Pacific region, several RFMOs are particularly relevant. The Western and Central Pacific Fisheries Commission (WCPFC) manages highly migratory tuna and billfish stocks across the western and central Pacific, maintaining detailed catch, effort, and stock assessment databases that member States can use to populate their asset accounts. The Indian Ocean Tuna Commission (IOTC) performs a similar function for tuna and tuna-like species in the Indian Ocean. The Commission for the Conservation of Southern Bluefin Tuna (CCSBT) manages the single global stock of southern bluefin tuna and provides allocation-based data useful for attributing shared stocks to individual countries. Countries participating in these organisations should utilise RFMO stock assessment outputs as primary inputs when compiling aquatic resource asset accounts, supplementing national data where domestic assessments are unavailable^[11].

3.1.3 Species Classification

The Food and Agriculture Organization (FAO) Aquatic Sciences and Fisheries Information System (ASFIS) provides a standard species classification containing over 11,500 species. This is linked to the International Standard Classification for Aquatic Animals and Plants (ISCAAP), which divides commercial species into 50 groups based on taxonomic, ecological, and economic characteristics^[12]. For accounting purposes, aquatic resources can be grouped into nine divisions:

1. Freshwater fishes
2. Diadromous fishes (species migrating between fresh and salt water)
3. Marine fishes
4. Crustaceans
5. Molluscs
6. Whales, seals and other aquatic mammals
7. Miscellaneous aquatic animals
8. Miscellaneous aquatic animal products
9. Aquatic plants

3.2 Stock Assessment Integration

For detailed methodology on linking stock assessment models to accounting structures, see TG-6.7 Fisheries Accounting: Integrating Stock Assessment.

3.2.1 Physical Asset Accounts for Aquatic Resources

The account structure follows TG-3.1 Asset Accounts; the fisheries-specific entries are detailed in the table below^[13]:

Following SEEA CF Table 5.22, extraction flows (gross catch/harvest) are shown separately from "other changes in volume" (natural mortality, catastrophic losses, uncompensated seizures, reappraisals, and reclassifications). This separation reflects the conceptual distinction between human-driven removals that enter the production account and stock-biological or institutional changes that do not. Only extraction flows enter the depletion test in Section 3.2.3; natural mortality does not constitute depletion. Units of measurement should be consistent across all entries, typically tonnes of live weight biomass. Conversion factors may be needed when data are available in different units (numbers of fish, processed weight)^[14].

3.2.2 Stock Assessment Methods

Fishery biologists employ various methods to estimate absolute stock size, including:

Virtual Population Analysis (VPA): A mathematical reconstruction of fish population dynamics based on age-structured catch data, using known catch numbers and estimated natural mortality to work backward through time and estimate historical population sizes^[15].

Tag-recapture analysis: Physical or electronic tagging of individuals followed by recapture to estimate population size based on the proportion of tagged fish in subsequent catches^[16].

Acoustic and trawl surveys: Direct measurement using echo-sounders, trawl surveys, or visual observation (including drone and satellite-based observation for surface species) to estimate biomass within surveyed areas, extrapolated to the full stock range^[17].

Catch Per Unit Effort (CPUE): When absolute stock size estimates are unavailable, CPUE provides an index of relative abundance. The ratio of catch to effort (fishing days, gear deployed, vessel power) serves as a proxy indicator of stock density, though this approach requires careful adjustment for changes in technology, fleet composition, and management arrangements^[18]. It is important to record the impact of changes in model parameters as reappraisals in the asset accounts to distinguish methodological revisions from actual physical changes in stock size^[19].

Countries with limited capacity for full stock assessments can still compile informative aquatic resource accounts by adopting a tiered approach to data requirements. At the most basic level (Tier 1), countries can use catch time series combined with CPUE indices to derive relative abundance trends, which support qualitative assessments of whether stocks are increasing, stable, or declining. At an intermediate level (Tier 2), surplus production models such as the Schaefer model can be fitted to catch and effort data to generate estimates of maximum sustainable yield and current biomass relative to B_MSY, without requiring age-structured data. At the most detailed level (Tier 3), full age-structured or length-based assessments provide absolute biomass estimates and fishing mortality rates. Countries should aim to compile accounts at the highest tier supported by their data, while recognising that even Tier 1 accounts--when consistently maintained over time--provide valuable information on stock trajectories and can flag potential sustainability concerns^[20].

The following table maps each tier to the physical asset account entries it can support. Entries marked "proxy" require an indicative estimate rather than a model-based value; entries marked "omit (document)" should be left blank with an explanatory metadata note.

Table 3.2.2: Tier-to-account-entry mapping for physical asset accounts

At Tier 1, accounts can still support directional judgements (improving/stable/declining) useful for flagging potential sustainability concerns, even without absolute biomass estimates.

3.2.3 Sustainable Yield and Depletion

A critical concept linking stock assessment to accounting is sustainable yield--defined as "the surplus or excess of animals or plants that may be removed from a population without affecting the capacity of the population to regenerate itself" (SEEA CF para 5.82)^[21]. For any given population, if extraction is less than sustainable yield, no depletion should be recorded. Depletion occurs only when extraction exceeds sustainable yield, representing a genuine reduction in the asset base.

The sustainable yield concept derives from population biology models that relate harvest to stock size. At low population sizes, little surplus is available for harvest because absolute reproduction is limited. At high population sizes approaching carrying capacity, surplus is also limited because density-dependent factors reduce reproduction. Maximum Sustainable Yield (MSY) occurs at intermediate population levels where the combination of population size and per-capita reproduction generates the largest surplus^[22].

Modern fisheries management increasingly uses precautionary reference points that provide a buffer below MSY to account for uncertainty in stock assessments and environmental variability. These include F_0.1 (fishing mortality at which the slope of the yield-per-recruit curve is 10% of the slope at the origin) and B_lim (limit reference point for biomass below which recruitment may be impaired)^[23].

Depletion of natural aquatic resources, in physical terms, equals total removals less sustainable yield, where total removals comprise gross catch (including discards), resident illegal or unreported catch, and non-resident illegal extraction (see Section 3.6.3 for the treatment of IUU components). Since population dynamics are modelled with uncertainty, year-to-year variation between estimated sustainable yield and actual growth must be expected. Depletion should be recorded whenever total removals exceed sustainable yield as estimated in the current-year stock assessment; no separate threshold for "normal variation" is applied because the sustainable yield estimate already incorporates expected biological variability^[24].

Climate change is altering fish stock productivity, distribution, and recruitment patterns, which has direct implications for the calculation of sustainable yield in asset accounts. As ocean temperatures shift, species ranges are moving poleward, productivity regimes are changing, and the carrying capacity of particular marine areas may increase or decrease. These changes mean that sustainable yield is not a fixed quantity but should be recalculated periodically to reflect current environmental conditions. When compiling accounts, compilers should use the most recent stock assessment outputs, which increasingly incorporate environmental covariates such as sea surface temperature and ocean productivity indices. Where formal stock assessments are not updated frequently, compilers should document the environmental assumptions underlying existing sustainable yield estimates and note any known environmental shifts that may affect their validity. Adjustments to reference points (such as recalculating B_MSY or F_MSY under changed productivity assumptions) should be recorded as reappraisals in the asset account rather than as physical changes in stock size, thereby maintaining the integrity of the accounting framework^[25].

3.3 Economic Performance Indicators

For comprehensive guidance on ocean economy measurement, see TG-2.5 Ocean Economy Structure.

3.3.1 Production and Value Added

The primary economic indicators derive from supply and use accounts that record the output of fisheries industries. Key measures include:

Gross output: The total value of fish and fishery products produced, valued at basic prices (excluding taxes on products)^[26].

Intermediate consumption: The value of goods and services used as inputs in fishing operations, including fuel, gear, bait, ice, and vessel maintenance.

Gross value added (GVA): The difference between gross output and intermediate consumption, representing the contribution of the fisheries sector to GDP.

Net value added: GVA less consumption of fixed capital (depreciation of vessels and equipment) and, following the 2025 SNA treatment, less depletion of natural fish stocks^[27].

These measures can be compiled for the fisheries sector as a whole or disaggregated by:

• Type of fishing (commercial, artisanal/small-scale, recreational, subsistence)
• Fishing method or gear type (trawl, purse seine, longline, gillnet, etc.)
• Target species or species groups
• Geographic area or fishing ground
• Enterprise size (by vessel tonnage, crew size, or revenue)

3.3.2 Employment Indicators

Employment in fisheries encompasses diverse working arrangements from large commercial operations to small-scale artisanal fishing. Key employment indicators include:

• Number of persons engaged in fishing activity
• Full-time equivalent (FTE) employment
• Employment by gender, age, and other demographic characteristics
• Compensation of employees in the fisheries sector
• Mixed income of owner-operators and unincorporated fishing enterprises

Employment data should distinguish between employment in capture fisheries and employment in aquaculture, and may further distinguish processing and marketing activities within the broader fisheries value chain^[28].

Small-scale fisheries employ an estimated 90 per cent of the world's capture fishers and fish workers, yet these workers are frequently undercounted in official labour statistics because many operate informally, seasonally, or on a part-time basis^[29]. To improve coverage, countries should consider supplementing standard labour force surveys with targeted approaches. These include adding fisheries-specific modules to household surveys that capture seasonal and part-time fishing activity; conducting frame surveys at landing sites and fishing communities to enumerate active fishers, vessels, and gear; using key-informant interviews in coastal and riparian communities to validate administrative records; and cross-referencing vessel and licence registries with labour market data where registration systems exist. Where direct survey coverage remains limited, proxy estimation methods--such as applying average crew sizes to registered vessel counts or using per-capita fish consumption to estimate subsistence harvesting effort--can provide reasonable orders of magnitude. Countries participating in the Global Strategy to Improve Agricultural and Rural Statistics (GSARS) may draw on its guidelines for designing cost-effective fisheries employment surveys^[30].

3.3.3 Trade and International Flows

Fisheries are a globally traded commodity with significant international flows. Relevant trade indicators include:

• Exports and imports of fish and fishery products (volume and value)
• Trade balance in fishery products
• Main trading partners and export markets
• Foreign direct investment in the fishing sector

For countries whose residents harvest fish from other countries' EEZs, the accounting must carefully distinguish between: (a) catches from national aquatic resources regardless of who harvests them, and (b) catches by national fishing operations regardless of where they fish^[31]. This distinction is essential for correctly measuring changes in national aquatic resource stocks versus national fishing industry output.

3.4 Sustainability Indicators

3.4.1 Stock Status Indicators

Physical asset accounts provide the foundation for key stock status indicators:

Stock biomass relative to reference points: Comparing current estimated biomass (B) to biological reference points such as:

• B_MSY: Biomass at which MSY is achieved
• B_0: Unfished (virgin) biomass
• B_lim: Limit reference point below which recruitment is impaired

Fishing mortality relative to reference points: Comparing current fishing mortality rate (F) to:

• F_MSY: Fishing mortality that produces MSY
• F_0.1: Precautionary proxy for F_MSY
• F_lim: Limit above which stock decline is expected

Proportion of stocks within biologically sustainable levels: SDG indicator 14.4.1 measures the percentage of fish stocks that are within biologically sustainable levels, defined as stocks with abundance at or above the level that can produce MSY^[32].

3.4.2 Depletion-Adjusted Income Measures

The 2025 SNA now treats depletion of natural resources as a cost of production alongside depreciation, giving greater prominence to net income measures that account for the using up of natural capital (SNA 2025 Annex 4, para A4.59)^[33]. Countries that have not yet transitioned to SNA 2025 can compile depletion-adjusted income measures as supplementary or satellite account entries consistent with SNA 2008; the SEEA Central Framework provides a version-neutral basis for these calculations (SEEA CF Section 5.8), enabling countries at any stage of SNA transition to produce meaningful depletion-adjusted indicators. For fisheries, this means:

Net fishing income: Gross value added from fishing less the value of depletion. This measure reflects the genuine contribution of fisheries to national income after accounting for any reduction in the fish stock asset.

Sustainable net income: Income that could be earned indefinitely if harvesting were limited to sustainable yield levels. Operationally, sustainable net income can be approximated as: SNI = GVA × (SY / gross catch), where SY is the sustainable yield at current biomass and gross catch is actual extraction for the period. This scaling approach assumes that costs and revenues are proportional to catch volume. Where unit cost data are available, a more precise formulation is: SNI = SY × (average price per tonne − average cost per tonne). For a numerical illustration, see the companion monetary example in Step 1b of Section 3.5.2. More detailed methodology, including treatment of multi-species fisheries and long-run price assumptions, is covered in TG-6.7 Fisheries Accounting: Integrating Stock Assessment.

When depletion occurs (extraction exceeds sustainable yield), the difference between gross income and sustainable net income represents income generated by depleting capital rather than genuine sustainable returns.

3.4.3 SDG 14 Alignment

Ocean Accounts support monitoring of several SDG 14 targets related to fisheries^[34]:

SDG 14.4: "By 2020, effectively regulate harvesting and end overfishing, illegal, unreported and unregulated fishing and destructive fishing practices and implement science-based management plans, in order to restore fish stocks in the shortest time feasible, at least to levels that can produce maximum sustainable yield as determined by their biological characteristics."

• Indicator 14.4.1: Proportion of fish stocks within biologically sustainable levels
• Asset accounts directly provide data on stock status relative to MSY benchmarks. SDG 14.4.1 uses an unweighted stock-count method: each assessed stock is counted equally, and the indicator equals the number of stocks at or above B_MSY divided by the total number of assessed stocks. Where a country's fisheries data are already disaggregated by species or stock in pre-existing fisheries data systems, those disaggregated stock records feed directly into the count without further aggregation. Compilers should follow FAO's indicator methodology note (FAO 2020, footnote 34) for official SDG reporting. Alternative weightings by catch volume or landed value may be informative for national monitoring purposes but should not replace the FAO unweighted method for official SDG submissions.

SDG 14.6: "By 2020, prohibit certain forms of fisheries subsidies which contribute to overcapacity and overfishing, eliminate subsidies that contribute to illegal, unreported and unregulated fishing and refrain from introducing new such subsidies."

• Environmental subsidy accounts can track government support to the fisheries sector
• Analysis can assess whether subsidies enhance or undermine sustainability

SDG 14.7: "By 2030, increase the economic benefits to small island developing States and least developed countries from the sustainable use of marine resources, including through sustainable management of fisheries, aquaculture and tourism."

• Indicator 14.7.1: Sustainable fisheries as a proportion of GDP in small island developing States, least developed countries and all countries
• Directly derived from economic accounts measuring fisheries GVA

SDG 14.b: "Provide access for small-scale artisanal fishers to marine resources and markets."

• Indicator 14.b.1: Degree of application of a legal/regulatory/policy/institutional framework which recognizes and protects access rights for small-scale fisheries
• Disaggregated accounts can track the distribution of fisheries benefits across scales of operation

3.5 Practical Applications

3.5.1 Informing Total Allowable Catch Decisions

Fisheries managers commonly set Total Allowable Catch (TAC) limits based on biological stock assessments. Ocean Accounts enhance this process by:

• Providing a systematic framework for recording and updating stock information
• Enabling comparison of catch levels against sustainable yield benchmarks
• Tracking the cumulative impact of harvesting decisions on stock levels over time
• Integrating economic information to assess the costs and benefits of different TAC options^[35]

The following decision framework illustrates how data from physical asset accounts and stock assessments can be combined to guide TAC decisions. By cross-referencing the current stock status (expressed as the ratio of biomass to the biomass at maximum sustainable yield, B/B_MSY) with recorded catch relative to sustainable yield (SY), managers can identify the appropriate management response.

Table 3.5.1: Sustainable yield decision framework for fisheries management

This decision matrix translates accounting outputs into actionable management guidance. When a stock is healthy (B >= B_MSY) and catch does not exceed sustainable yield, no depletion is recorded and the current TAC can be maintained. When catch exceeds sustainable yield even for a healthy stock, depletion is recorded in the asset account, signalling that the TAC should be reduced to prevent the stock from falling below its MSY benchmark. For depleted stocks, even catch levels at the current (reduced) sustainable yield merely stabilise the stock at its depleted level rather than rebuilding it; active rebuilding requires catch below sustainable yield. Catch exceeding sustainable yield for a depleted stock represents the most urgent case for TAC reduction. Managers should interpret these categories in conjunction with the precautionary reference points discussed in Section 3.2.3 and with due regard for uncertainty in stock assessment estimates^[36].

Estimating current SY for depleted stocks: For the two depleted rows in Table 3.5.1 (B/B_MSY < 1.0), "current SY" is the sustainable yield at the stock's actual (reduced) biomass, which is lower than MSY. The method for estimating this value depends on the data tier in use. At Tier 1, use the Schaefer model approximation: SY_current = MSY × (B/B_MSY), noting that this assumes a symmetric production curve and should be treated as indicative only. At Tier 2 and above, the surplus production or age-structured model used in the stock assessment will directly provide a current-biomass-conditional yield estimate; the Schaefer approximation should not be substituted in these cases. Reference the Tier 2 surplus production model guidance in Section 3.2.2 as the appropriate tool for Tier 2+ calculations.

3.5.2 Worked Example: Using Asset Account Data to Inform Quota Decisions

This worked example demonstrates how a fisheries management agency can use asset account data to assess stock status and adjust Total Allowable Catch quotas, using synthetic data for a hypothetical coastal demersal fishery.

Scenario description: The Coastal Demersal Fishery Management Authority oversees a commercially important snapper species within the national EEZ. The fishery is managed using annual TAC quotas allocated through an Individual Transferable Quota (ITQ) system. Stock assessment scientists conduct annual assessments using age-structured models calibrated to catch data, fishery-independent trawl surveys, and commercial CPUE indices. The authority compiles physical asset accounts for the snapper stock, integrated with the stock assessment process.

Step 1: Compile physical asset account

The authority compiled the following physical asset account for snapper stock for the accounting year 2024, based on the 2024 stock assessment:

Note: Sustainable yield is stock-dependent and varies with biomass. At the current depleted biomass of 40,600 tonnes (B/B_MSY = 0.74), the estimated sustainable yield of 8,500 tonnes represents the harvestable surplus above natural mortality—the quantity that can be removed by human harvest without reducing stock biomass below its current level. Depletion is therefore measured as total removals (gross catch plus all IUU extraction, whether by residents or non-residents) minus that harvestable surplus: 10,800 - 8,500 = 2,300 tonnes. Natural mortality of 5,800 tonnes is recorded separately in the reductions block as a stock-biological process distinct from the harvest-based depletion test; it does not enter the depletion calculation. As the stock rebuilds toward B_MSY, sustainable yield will increase toward its maximum.

Step 1b: Compile monetary asset account

Using a unit resource rent approach (SEEA CF paras 5.441-5.452), the authority monetises the physical account. All figures are illustrative.

The depletion value of USD 920,000 represents stock capital eroded in 2024. Net fishing income of USD 3,280,000 is the sector's genuine contribution to national income after accounting for this capital drawdown. These monetary measures provide the inputs for depletion-adjusted GDP as described in Section 3.4.2.

Step 2: Assess stock status against decision framework

The authority applies the decision framework from Table 3.5.1:

• Stock status: B/B_MSY = 0.74, indicating the stock is below MSY benchmark (depleted)
• Catch relative to sustainable yield: Total removals (10,800) > sustainable yield (8,500), so depletion is recorded (2,300 tonnes)
• Decision category: "< 1.0 (depleted)" AND "Catch > current SY" → Urgent TAC reduction

Step 3: Calculate TAC adjustment

The management authority determines that the TAC should be reduced to allow stock rebuilding. Two scenarios are considered:

Scenario A: Reduce catch to current sustainable yield level

• Set TAC for 2025 at 8,500 tonnes (equal to current sustainable yield at present biomass)
• This prevents further depletion but does not actively rebuild the stock
• At this catch level, stock biomass would stabilise near the current level (approximately 40,600 tonnes), remaining below B_MSY

Scenario B: Reduce catch below sustainable yield to enable rebuilding

• Set TAC for 2025 at 7,000 tonnes (below sustainable yield by 1,500 tonnes)
• Stock expected to increase by approximately 1,500 tonnes per year
• Rebuilding target: return to B_MSY (55,000 tonnes) within 10 years
• Required annual rebuilding increment: (55,000 - 40,600) / 10 = 1,440 tonnes/year
• TAC of 7,000 tonnes achieves this rebuilding trajectory

The authority selects Scenario B, setting the 2025 TAC at 7,000 tonnes, representing a 33% reduction from 2024 gross catch.

Step 4: Communicate decision using asset account framework

The authority publishes the decision with the following justification, grounded in asset accounting concepts:

"The 2024 physical asset account for snapper stock shows closing biomass of 40,600 tonnes, 26% below the B_MSY reference level of 55,000 tonnes. Total removals of 10,800 tonnes (gross catch 10,500 plus IUU 300) exceeded sustainable yield of 8,500 tonnes, resulting in depletion of 2,300 tonnes of stock capital. To reverse this trajectory and rebuild the stock asset to sustainable levels within 10 years, the 2025 Total Allowable Catch is set at 7,000 tonnes. This reduction allows net stock growth of approximately 1,500 tonnes per year. Continued monitoring through annual asset accounts will track rebuilding progress, and the TAC will be adjusted as the stock approaches the MSY target."

Step 5: Monitor rebuilding through subsequent accounts

Monitoring actions for each assessment tier are set out in Table 3.5.1.

3.5.3 Evaluating Fisheries Subsidies

Governments provide various forms of support to fisheries, from fuel subsidies to vessel construction programs. Ocean Accounts enable systematic assessment of:

• The magnitude and composition of fisheries subsidies
• Whether subsidies enhance capacity (potentially harmful) or improve sustainability (beneficial)
• The distributional effects of subsidies across different types of fishing operations
• Alignment with international commitments under SDG 14.6 and WTO fisheries subsidies disciplines^[37]

3.5.4 Assessing Recovery Programs

For depleted stocks, recovery programs aim to rebuild populations to sustainable levels. Ocean Accounts support:

• Baseline measurement of stock status at program initiation
• Tracking of stock recovery through periodic asset accounts
• Assessment of economic impacts during rebuilding periods (short-term costs)
• Evaluation of long-term benefits from restored sustainable harvesting^[38]

3.5.5 Quota Valuation and Management

Individual Transferable Quotas (ITQs) are an increasingly common approach to fisheries management. When quotas are freely traded, their market prices can inform the valuation of fish stocks^[39]. Ocean Accounts support:

• Recording quota values as assets (permits to use environmental assets under SEEA CF para 4.178)
• Tracking changes in quota values over time
• Distinguishing between the value of quotas and the value of underlying fish stocks
• Assessing the equity implications of quota allocation systems

When using ITQ market prices to estimate the value of fish stock assets, compilers should be aware that quota prices may not fully reflect the underlying resource value. Quota markets are often thin (few transactions), geographically segmented, and subject to regulatory constraints on ownership concentration and foreign participation that can distort prices. In addition, quota prices reflect private expectations of future harvesting returns, which may diverge from the social value of the resource. Where quota markets exist, their prices can serve as a useful cross-check against net present value estimates derived from resource rent approaches. The primary reference for ITQ treatment as environmental assets is SEEA CF paras 4.178-4.180, which establish the asset classification for permits to use environmental assets. The valuation method—resource rent and net present value approaches—is provided in SEEA CF paras 5.441-5.452. Quota prices should not be treated as the sole basis for monetary asset valuation without careful assessment of market conditions^[40].

3.5.6 Climate Change Adaptation

Climate change is affecting fish stock distribution, productivity, and sustainable yield levels. Ocean Accounts can support climate adaptation by:

• Tracking shifts in stock distribution across spatial accounting units
• Monitoring changes in condition indicators that may signal climate impacts
• Adjusting sustainable yield estimates to account for changing environmental conditions
• Informing adaptive management responses to climate-driven changes^[41]

3.5.7 Community-level Fishery Accounting

[This section is under active development. Guidance will be updated as community-level OA practice matures. Practitioners seeking current methodology should contact the GOAP small-scale fisheries working group.]

The ocean accounting framework can be applied not only at national scale but also at community level to capture the economic contributions of small-scale and subsistence fishing that are often missed in standard economic surveys. The International Institute for Environment and Development (IIED) developed survey tools and toolkits examining subsistence and recreational supply of ocean-related natural inputs relevant to small-scale fisheries, with a focus on understanding how coastal communities depend on and contribute to ocean resources^[42]. In a complementary effort, the Environmental Defense Fund (EDF) undertook community-level fisheries accounting work in Baja California, Mexico, demonstrating that accounting principles derived from the SEEA Central Framework and Ocean Accounts methodology could be operationalised at local scales to inform cooperative fisheries management.

These initiatives illustrated that structured accounting approaches can render visible the economic value of artisanal and subsistence catches--value that conventional national accounts frequently undercount or omit entirely. By capturing household-level resource flows and linking them to ecosystem condition indicators, community-scale accounts provide a bridge between national statistical frameworks and local management needs. The IIED/EDF framework (2015-2019) remains the most recent published methodology at the time of writing; no formal superseding guidance has been published. [Editor note: confirm current status of Kenya and Indonesia fisheries OA pilots before citing.]

Case illustration: Community Fishery Accounts in Baja California (2015--2019)

Work by the International Institute for Environment and Development (IIED) on survey methodologies and toolkits for small-scale fisheries, together with efforts by the Environmental Defense Fund (EDF) beginning in 2015 in Baja California, Mexico, demonstrated that ocean accounting frameworks can be applied at the community scale. The EDF programme compiled fishery accounts for remote fishing villages, capturing the economic contributions of small-scale and subsistence fishing that are typically missed in standard economic surveys. These efforts highlight the potential for community-level accounts to complement national-level compilations, particularly for capturing non-market and subsistence ocean economy contributions^[43].

3.6 Data Sources and Compilation Considerations

3.6.1 Primary Data Sources

Compilation of fisheries accounts typically draws on:

Catch and landing statistics: Recorded by fisheries agencies, port authorities, or fish market operators. FAO collects and publishes global capture and aquaculture production data annually through FishStatJ (www.fao.org/fishery/statistics/software/fishstatj)^[44]. FishStatJ covers capture production and aquaculture output for over 200 countries and territories, disaggregated by species group and FAO major fishing area, with time series typically updated annually with a one- to two-year lag. The database is the primary global benchmark for national catch reconciliation and is freely downloadable as a desktop application. Key limitations include: (a) data are reported at country level on the basis of declared landings and may not reflect unreported or illegal catch; (b) discards are not included in standard production tables and must be estimated separately using observer or logbook data; and (c) government subsidies to the sector are not captured within FishStatJ and require separate compilation from national budget sources or the OECD Fisheries Support Estimate database.

Stock assessment reports: Produced by national fisheries research institutions, regional fisheries management organizations (e.g., WCPFC, IOTC, CCSBT for tuna), or international bodies. The RAM Legacy Stock Assessment Database provides standardized stock assessment outputs.

Vessel and licence registries: Providing data on fishing capacity, effort, and fleet composition.

Economic surveys: Dedicated fisheries economic surveys or general business surveys covering fishing enterprises.

Trade statistics: Customs data on fish imports and exports, compiled according to the Harmonized System (HS) commodity classification.

Employment surveys: Labour force surveys or dedicated fisheries employment surveys.

3.6.2 Intergovernmental Fisheries Data Sources

Intergovernmental organisations play a significant role in collecting and harmonising fisheries data across countries. Key active sources and initiatives relevant to compiling ocean accounts for fisheries are summarised in Table 3.6.1 below^[45].

Table 3.6.1: Intergovernmental fisheries data sources and initiatives

3.6.3 Illegal, Unreported, and Unregulated (IUU) Fishing

IUU fishing presents significant measurement challenges. The accounting treatment differs depending on whether the illegal catch is by residents or non-residents, and compilers must apply these treatments separately.

Illegal catches by residents (domestic IUU) are still treated as production by the national fishing industry regardless of legality, per SEEA CF para 5.435. They are recorded as gross catch/extraction in the physical asset account and as output in the production account. Residence, not legality, determines the production boundary. Where domestic IUU can be estimated, it should be added to reported landings in the gross catch row of the asset account.

Illegal catches by non-residents are recorded as "uncompensated seizures" in the asset account (a separate reductions line), distinguishing them from production by the country's nationals. These represent a transfer of natural capital to foreign operators without compensation, per SEEA CF para 5.436.

Following these accounting principles, illegal catches by residents should still be recorded as production with income accruing to the fisher^[46]. The practical implication: resident IUU must be included in the gross catch figure that flows into the depletion calculation, while non-resident IUU appears in the separate "uncompensated seizure" line as shown in the worked example in Section 3.5.2.

Estimates of IUU fishing are inherently uncertain but important for understanding true extraction levels and their impact on stock sustainability. Global IUU catch has been estimated at 11--26 million tonnes annually (Agnew et al., 2009), with significant regional variation.

Countries should develop national IUU estimation approaches appropriate to their data environment and fishery characteristics. Commonly used methods include comparison of reported landings with independent estimates of total removals derived from port sampling, at-sea observer programmes, or vessel monitoring system (VMS) data; stock assessment--based back-calculation, in which the difference between model-estimated total removals and reported catch provides an implied IUU component; trade-based analysis, comparing declared domestic landings with apparent consumption (production plus imports minus exports) to identify discrepancies; and aerial and satellite surveillance data, which can detect unreported fishing activity by matching vessel positions with licence registers. Regardless of the method chosen, IUU estimates should be presented with explicit uncertainty bounds and documented in the metadata accompanying the accounts. Where multiple methods yield different estimates, compilers should report a range and indicate the preferred central estimate^[47].

3.6.4 Subsistence and Recreational Fishing

Fisheries accounts should encompass all harvesting activity, not only commercial operations. Subsistence fishing for household consumption represents production for own final use. Recreational fishing, while not undertaken for commercial purposes, still removes fish from stocks and should be recorded^[48].

These non-commercial catches may require special estimation approaches based on:

• Household surveys with questions on fishing activity and consumption
• Recreational fishing licence data (where licensing exists)
• Creel surveys at popular fishing locations
• Proxy indicators based on boat ownership or coastal population

Small-scale and subsistence fisheries are of particular importance in developing countries and in many GOAP member countries in the Asia-Pacific region, where they may represent a substantial proportion of total catch and provide essential food security and livelihoods for coastal communities. In several Pacific Island States, for example, subsistence and artisanal catches may equal or exceed commercial catches in volume, yet remain largely unreported. Countries compiling fisheries accounts should assess the relative importance of non-commercial catches in their national context and allocate survey resources accordingly. Where comprehensive survey programmes are not feasible, countries may consider periodic benchmark surveys at representative landing sites combined with extrapolation methods, integration of fisheries questions into existing multi-purpose household surveys (such as Household Income and Expenditure Surveys), and use of food balance sheet data and per-capita fish consumption estimates to cross-check catch figures. The FAO Guidelines for Securing Sustainable Small-Scale Fisheries provide an international framework that can inform the design of data collection strategies for this sector^[49].

4. Acknowledgements

Authors: [To be confirmed]

Reviewers: [To be confirmed]

5. References