Transboundary Data Sharing and Integration

• TG-0.1 General Introduction to Ocean Accounts — for the conceptual framework and core accounting components that transboundary data must feed into.
• TG-4.6 Data Harmonisation and Interoperability — for the baseline data standards and interoperability protocols applied within and between countries, which TG-4.12 extends to cross-border contexts.
• TG-4.7 National Data Coordination Architectures — for the domestic institutional arrangements upon which transboundary coordination builds. TG-4.12 is explicitly a cross-border extension of TG-4.7.

Helpful background:

• TG-0.7 Quality Assurance Principles — for the quality dimensions that must be maintained when integrating externally sourced data into national accounts.
• TG-4.2 Survey Methods for Ocean Economic Activity — for survey design in shared sea areas, including harmonising survey frames between neighbouring countries.

Data requirements:

• Existence of a national ocean accounts focal point or coordinating body with authority to engage in bilateral data exchange discussions.
• Access to existing bilateral or multilateral frameworks (treaty, convention, MoU) under which a data exchange channel can be formalised or activated.

Legal and institutional requirements:

• National statistical legislation or data sharing policy that explicitly permits sharing of statistical data with foreign counterparts (or a privacy and confidentiality assessment confirming that exchange is lawful).
• Identified counterpart agency in partner country with comparable data mandate.

Technical requirements:

• Common or mappable spatial reference systems (WGS84 recommended) and agreed temporal reference period.
• Metadata standard adopted by both parties. ISO 19115 is the minimum recommended standard for geographic data.

Ocean accounting is inherently transboundary. Large Marine Ecosystems (LMEs) span multiple jurisdictions. Shared fish stocks cannot be assessed without data exchange between the flag states and coastal states involved, and ecosystem processes — ocean currents, pollution plumes, species migrations — do not respect political boundaries. The SEEA Ecosystem Accounting framework acknowledges that “ecosystem accounting may cover sub-national to supranational domains”, implicitly requiring cooperative data input wherever accounting areas straddle national boundaries.

This section provides guidance across five dimensions: conceptual framing (Section 3.1), governance and legal arrangements (Section 3.2), technical standards for data exchange (Section 3.3), institutional coordination mechanisms (Section 3.4), and reporting and integration (Section 3.5).

Jurisdictional transboundary. Data collected by one state are needed by another to compile accounts. A fishing vessel flagged in State A but landing catch in State B may appear in neither country’s accounts without an exchange of vessel monitoring and landing records. Similarly, economic activity data for ocean industries that operate across borders — maritime transport, offshore energy exploration — may be held by the country where the activity is registered rather than the country where the environmental impact occurs. Jurisdictional transboundary data exchange addresses these mismatches between data custody and accounting need.

Ecosystem transboundary. Ecological processes that sustain ocean ecosystem services operate independently of political boundaries. Ocean currents that distribute nutrients, larval dispersal that connects reef systems across EEZs, and migratory species that cycle through the high seas all generate ecosystem services that accrue to multiple countries. Accounting for these services — and for the degradation they may suffer — requires integrating biophysical data from multiple national monitoring systems and, in some cases, from international observation platforms such as Argo floats and the Global Ocean Observing System (GOOS).

These three senses are not mutually exclusive. A shared mangrove ecosystem (geographic transboundary) may generate carbon sequestration services (ecosystem transboundary) that are relevant to both countries’ nationally determined contributions under the Paris Agreement, requiring exchange of both extent and condition data (jurisdictional transboundary). Compilers should identify which sense or senses apply to each data gap they face, as this determines which legal instruments and coordination mechanisms are relevant.

Relationship to TG-4.7. TG-4.7 addresses coordination among domestic agencies — the NSO, fisheries authority, environmental monitoring body, and other national actors that hold relevant data. TG-4.12 extends this to international coordination: the same committee models, data sharing agreement elements, and trust frameworks described in TG-4.7 have regional analogues, but the legal instruments differ (bilateral treaties rather than national MOUs), the institutional actors differ (regional fisheries bodies and regional seas secretariats rather than national line agencies), and the confidentiality regime differs (considerations of national sovereignty alongside statistical confidentiality). Compilers should read TG-4.7 before TG-4.12. This Circular assumes familiarity with TG-4.7’s three committee models, trust framework dimensions, and modular implementation phases.

SEEA EA boundary-setting. The SEEA EA permits ocean accounting areas to be defined at any scale, from a sub-national coastal zone to a multi-country Large Marine Ecosystem. Where a country chooses to compile accounts for an LME or shared sea, transboundary data exchange is a structural requirement of the accounting boundary chosen. Countries should therefore clarify their intended accounting boundary (see TG-4.7 Section 3.1 and TG-0.8 Implementation Readiness Assessment) before designing transboundary data exchange arrangements, so that exchange agreements are scoped to match the accounting area.

3.2 Governance and Legal Arrangements

Transboundary data exchange for ocean accounting operates within a layered architecture of international legal instruments, regional conventions, and bilateral agreements. This section describes that architecture using a tiered framework and identifies the key instruments at each tier.

Tier 1 — Global treaty obligations.

UNCLOS (UN Convention on the Law of the Sea, 1982) is the foundational instrument. Several provisions create direct obligations or permissions for data sharing relevant to ocean accounting:

The Agreement under UNCLOS on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ Agreement, 2023) introduces new data sharing obligations for marine genetic resources and Environmental Impact Assessments in the high seas. Countries with accounting interests in the high seas or in exclusive economic zones adjacent to areas beyond national jurisdiction should assess the BBNJ Agreement’s data provisions as a potential source of both obligations and data flows for ocean accounting. (As of May 2026 the BBNJ Agreement had not yet entered into force. Countries should monitor ratification progress and assess data provision obligations accordingly.)

The Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization (2010, in force 2014) creates obligations for access to and sharing of biological samples and associated genetic resource data. Where ocean accounting extends to marine genetic resources or biodiversity observation data that include genetic resource information — relevant for ecosystem condition accounts in high-biodiversity areas — compilers should assess whether the Nagoya Protocol’s access and benefit-sharing provisions apply to the data exchange. The BBNJ Agreement’s data sharing provisions build on the Nagoya Protocol framework for areas beyond national jurisdiction.

The UN Fundamental Principles of Official Statistics (Principle 6) affirms that individual data collected by statistical agencies are confidential and are to be used exclusively for statistical purposes. This principle applies when a country shares statistical microdata internationally, and data sharing agreements must include provisions confirming that statistical confidentiality is upheld by the receiving party.

Tier 2 — Regional seas conventions and equivalent bodies.

Regional seas conventions provide the most operationally accessible legal framework for transboundary ocean accounting data exchange. Each convention establishes a secretariat, working groups, and often data exchange protocols that can serve as the institutional infrastructure for accounting data sharing:

Tier 3 — Bilateral and sub-regional agreements.

Where global or regional instruments do not provide a sufficient legal basis for the specific data exchange needed, bilateral MOUs or data sharing agreements between countries provide a pragmatic alternative. The elements of such agreements are analogous to those described for domestic data sharing agreements in TG-4.7 §3.2, with the following additional considerations specific to bilateral international agreements:

Table 3.2.1: Governance framework for transboundary ocean accounting data

3.3 Technical Standards for Data Exchange

Transboundary data exchange requires both parties to adopt compatible technical standards for data structure, metadata, and transmission. The full catalogue of standards relevant to ocean accounting — spanning geospatial metadata, web service interfaces, statistical exchange, biodiversity occurrence records, and catalogue discovery — is treated in TG-4.6 Data Harmonisation and Interoperability. This section identifies only the cross-border-specific requirements that supplement that baseline.

TG-4.7 describes three national committee models (NSO-led, multi-agency, nested) through which domestic agencies coordinate ocean accounting data. These models have regional analogues, and the TG-4.7 typology provides a useful reference for understanding the corresponding international coordination structures. The defining difference is authority: at the domestic level, a committee can compel data sharing through statutory mandate or Ministerial direction, whilst at the international level, participation is voluntary. Trust and mutual benefit (as described in TG-4.7 Section 3.3) therefore become even more central to effective coordination.

Bilateral Technical Working Groups (BTWGs). The closest international analogue to the TG-4.7 Model A (NSO-led) bilateral data sharing agreement is the BTWG: a small expert group drawn from the NSO or lead environmental agency of each country, meeting annually to agree data exchange schedules, resolve quality discrepancies, and review data use. BTWGs are most appropriate where two countries share a well-defined accounting area (e.g., a jointly managed strait or shared mangrove coast) and have existing statistical cooperation at the national level. The BTWG should operate under a bilateral MoU (see Section 3.2) that formalises its mandate and data exchange obligations.

Regional coordination nodes. IOC Sub-Commissions (IOCARIBE for the Caribbean, IOCINDIO for the Indian Ocean, WESTPAC for the Western Pacific) provide pre-existing intergovernmental infrastructure for ocean data exchange. These bodies function as a regional analogue to the TG-4.7 Model C (nested) committee, coordinating data flows across many countries through a regional secretariat. Countries should map their existing participation in IOC Sub-Commission activities and assess whether ocean accounting data can be routed through those existing channels rather than requiring new bilateral arrangements. Holdings exposed through the IOC’s Ocean Data and Information System (ODIS) can be discovered without a bilateral request at all.

Data stewardship responsibilities. In transboundary arrangements, each country retains stewardship of the primary data it generates, whilst regional bodies and bilateral partners hold derived products agreed under the exchange arrangement. Data sharing agreements should specify: (a) which party holds the authoritative version of each dataset; (b) embargo periods before data are made publicly available; (c) attribution requirements when data are used in published accounts; and (d) update obligations — the frequency with which the custodian party will refresh the shared data.

The GOAP Secretariat is the primary entry point for accessing GOAP-funded technical assistance. Countries may also engage IOC capacity development initiatives (including the IOC Ocean Teacher Global Academy) and the capacity-building provisions of the relevant RFMO. Unequal capacity between partners that is not explicitly addressed frequently causes transboundary data exchange to default to one-directional flows that do not sustain long-term cooperation.

This architecture is illustrated in Figure 4.12.1.

Regional seas bodies and sub-regional groupings increasingly request harmonised ocean accounting data from member states for regional environmental assessments. OSPAR’s Quality Status Reports, HELCOM’s State of the Baltic Sea reports, the CTI-CFF Regional State of the Coral Triangle Report, and SPREP’s State of the Pacific Ocean report all require country-level data that can be aggregated regionally. Countries should align the spatial boundaries, temporal reference periods, and account classifications used in their national ocean accounts with the regional reporting requirements of the bodies of which they are members.

GOAP maintains a central data registry for member country ocean accounts. Countries with transboundary data exchange arrangements should notify the GOAP Secretariat of those arrangements so that cross-country accounting boundaries are correctly reflected in the registry and to avoid double-counting where the same shared ecosystem is reported by two countries. GOAP reporting templates for shared ecosystem accounts should align with the partner country’s national account submissions. The GOAP Secretariat provides harmonisation guidance for countries compiling accounts that overlap geographically.

Section 3.5.2 Global frameworks.

Three global frameworks make direct use of transboundary ocean accounting data:

Section 3.5.3 Integration into national accounts.

When data received under a transboundary agreement are incorporated into national ocean accounts, compilers must apply three additional steps beyond those required for domestic data:

Harmonisation: Apply the classification concordance and unit standardisation procedures in TG-4.6 Data Harmonisation and Interoperability to all received data before integration. This is particularly important for fisheries statistics, where species classification systems (FAO ASFIS, national systems), spatial aggregation units (FAO areas, ICES rectangles, national EEZ zones), and reporting periods may differ between countries.

Lineage documentation: Per the quality assurance requirements of TG-0.7 Quality Assurance Principles, all externally sourced data must be documented with: the originating country and custodian agency; the legal basis for the exchange (treaty article, MoU reference, or RFMO data access agreement); the version and vintage of the data received; any transformations applied during harmonisation; and known limitations or data quality caveats. This lineage documentation should be published as part of the national accounts metadata in accordance with the transparency requirements of the UN Fundamental Principles of Official Statistics.

Section 3.5.4 Requesting regional data at a resolution the account can use.

Regional bodies publish condition information in the geometry their own assessment cycle requires, which is normally an aggregate for the convention area and its sub-regions. An ecosystem account needs the same measurements attributed to ecosystem types. The two geometries are not interchangeable, and the mismatch defeats a condition account even where the underlying monitoring is long-running and dense.