Beyond historical catch: developing a climate-adaptive fisheries allocation framework for transboundary fish stocks under international law

1 Introduction

1.1 Background and context

Climate change is now transforming the oceans in ways that directly challenge the foundations of international fisheries governance. Rising sea temperatures, acidification and deoxygenation are driving marine species to shift their geographical ranges in “non-negligible” ways out of necessity, often poleward or into deeper, cooler waters, at rates estimated at up to 70 kilometres per decade (Doney et al., 2012; Poloczanska et al., 2013). These redistributions of fish stocks destabilise established management regimes, risk undermining established quota allocations, and may generate disputes between historically dominant fishing States and newly affected coastal States (Poloczanska et al., 2013). Whilst, therefore, it might be true, as Caddell writes (Caddell, 2021), citing the decision in The Grisbådarna Case, that “[i]t is a well-established principle of the law of nations that the state of things that actually exists and has existed for a long time should be changed as little as possible”, climate change means this is becoming increasingly difficult to maintain (Grisbådarna Case, 1909). Indeed, the law of the sea, designed around assumptions of relative ecological stability, now faces a legitimacy crisis as allocation systems premised on historical catch records become increasingly disconnected from ecological reality. What makes this even more challenging is that the poleward migration of species poses existential risks to already struggling and disadvantaged developing nations in the tropics, such as Caribbean nations (Palacios-Abrantes et al., 2025).

In light of these challenges, this article asks whether the present body and framework of international fisheries law can support the development of new, climate-adaptive allocation mechanisms that might be more capable of responding to climate-driven redistributions of fish stocks. As might be expected, this is a difficult question to answer; international law is made by consensus, and whilst there might well be losers from this development, there are also likely to be winners, which makes the agreement needed to drive changes to the law difficult to achieve. The article, however, will suggest that the existing framework of the international law of the sea, contained in instruments such as the United Nations Convention on the Law of the Sea 1982 (UNCLOS) (UNCLOS, 1982) and the United Nations Fish Stocks Agreement 1995 (UNFSA) (UNFSA, 1995, p3), already contains sufficient normative principles, such as cooperation, sustainability, the precautionary principle, ecosystem protection and equitable utilisation, to support a more adaptive allocation model. As such, the most serious obstacle to the adoption of an adaptive model is institutional, with the various Regional Fisheries Management Organisations (RFMOs) around the world generally emphasising ongoing stability and membership consensus over adaptation to changing realities.

1.2 Problem statement

The general goal of international fisheries law has always been to find a means of allocating fish stocks so that all States have the right to exploit resources within their own territory and sovereign exclusive economic zones (EEZs), subject to conservation obligations. The problem that occupied the minds of the drafters of UNCLOS was how to balance the tension between conservation and exploitation, alongside the difficulty facing newly developing coastal States seeking to establish their own fisheries industries where established States had already been fishing and had developed historical claims to the stocks concerned (UNCLOS III, 1974).

In practice, however, historical catch and fishing effort have remained particularly influential criteria in the allocation of fishing opportunities within RFMOs, frequently operating alongside other considerations such as zonal attachment, resource distribution and the interests of coastal and developing States (Seto et al., 2021; Bailey et al., 2013). This reliance on historical participation can favour continuity and predictability but may also make existing allocation arrangements difficult to adjust when the geographical distribution of stocks changes substantially.

It is important, however, to distinguish between the adaptability of conservation measures and the adaptability of allocation among States. Neither UNCLOS nor the UNFSA requires TACs or other conservation measures to remain static. On the contrary, UNCLOS Articles 61(2)–(3) and 119 require conservation measures to be informed by the best scientific evidence available and relevant environmental factors, while UNFSA Articles 5, 6, 10 and 14 similarly contemplate management based upon updated scientific information, uncertainty and changing conditions (UNCLOS, 1982, arts 61(2)–(3), 119; UNFSA, 1995, arts 5–6, 10(d), 14). Aggregate fishing opportunities may therefore increase or decrease as stock assessments change. The more difficult question addressed by this article concerns how those changing fishing opportunities are distributed among participating States. An allocation system may adjust the absolute tonnage available to each State as the overall TAC changes while nevertheless preserving relatively stable percentage shares between them. Consequently, the rigidity examined here should not be attributed to an assumption in UNCLOS or the UNFSA that either stocks or TACs are legally static. Rather, it arises principally from the continued influence of historically grounded allocation criteria and institutional practices that may preserve relative shares even where the geographical distribution, accessibility and socio-economic significance of a stock have materially changed (Seto et al., 2021; Sumaila et al., 2013).

As has already been seen, however, climate change now threatens to disrupt this static equilibrium. Stocks are beginning to shift into new jurisdictions, creating new winners and losers amongst States. As Cheung and others write, this is exemplified by the northward shift of Atlantic mackerel in recent years into Icelandic and Faroese waters (Cheung et al., 2010). This mackerel dispute has caused tension over access to a half-million tonne annual catch, highlighting the difficulty that climate change may have more widely in the future for existing allocation agreements (Cheung et al., 2010). Similarly, Pacific tuna governance reveals tensions between developed fishing States and climate-vulnerable small island developing States (SIDS) in that region. Another issue is the development of new emerging Arctic fisheries in formerly inaccessible waters, which further highlights the inadequacy of existing frameworks to manage newly accessible resources and has precipitated new agreements in the region, such as the Arctic Fisheries Agreement (CAOFA, 2018). All of these new disputes and difficulties underscore the urgent need for adaptive allocation mechanisms that reconcile ecological change with principles of equity and sustainability.

1.3 Literature context

Existing scholarship increasingly identifies climate-driven stock redistribution as a problem that sits at the intersection of several established debates in international fisheries law rather than as a discrete regulatory gap. Lennan provides an important starting point by demonstrating that shifting species distributions place pressure upon fisheries governance arrangements whose jurisdictional and institutional structures were not specifically designed to address climate-driven redistribution (Lennan, 2023). This problem does not necessarily arise because international fisheries law prohibits adaptation. Rather, it raises the question of whether existing legal principles can be translated into sufficiently responsive allocation practices when the geographical relationship between States and stocks changes (Dubik et al., 2019).

Engler develops this problem from the perspective of transboundary cooperation and the ecosystem approach. While ecosystem-based management provides a conceptual basis for responding to ecological dynamism, effective adaptation depends upon institutional arrangements capable of translating changing scientific information into cooperative management decisions (Engler, 2020). This brings the legal adaptability identified by Lennan into contact with the institutional problem: flexibility within the applicable legal framework does not itself guarantee corresponding flexibility in allocation practice.

Caddell’s analysis further exposes this tension by examining the limited interaction between climate change and established fisheries governance (Caddell, 2021). Fisheries instruments were not generally drafted with anthropogenic climate-driven redistribution specifically in mind, yet their existing concepts—including cooperation, conservation and relevant allocation considerations—may provide legal space for adaptation. The resulting difficulty is therefore less an absolute absence of applicable norms than uncertainty over how those norms should operate when ecological distributions depart significantly from historical patterns.

The allocation literature provides the final element of this debate. Studies of RFMO practice demonstrate the continuing influence of historical catch and effort in distributing fishing opportunities, notwithstanding the availability of broader allocation principles (Churchill, 2012). Taken together, these strands of scholarship suggest a more specific governance problem than a simple claim that international fisheries law is “static”: conservation rules are capable of responding to changing scientific assessments, but allocation institutions may remain anchored to historically derived distributive expectations.

This article builds upon these strands of scholarship by asking how the normative flexibility already present in international fisheries law can be translated into a structured approach to allocation when climate change alters the distribution of transboundary stocks. The relevant gap is therefore not the absence of scholarship on climate impacts, equity or adaptive fisheries governance individually. It lies in developing a legally grounded framework that brings changing stock distribution, historical participation, ecosystem sustainability, vulnerability, food security and distributive considerations into a common and transparent allocation structure.

1.4 Research objectives

The overarching objective of this article is to determine whether, and through what legal and institutional mechanisms, the existing international fisheries regime can accommodate climate-driven redistribution of transboundary fish stocks while maintaining ecological sustainability and distributive legitimacy. More specifically, the article seeks to move from diagnosis to institutional design: first identifying the extent to which existing allocation practices are vulnerable to ecological redistribution, then examining the adaptive capacity already available within international law and finally translating those findings into a structured climate-adaptive allocation framework. To pursue this overarching objective, the article has five specific objectives:

• To evaluate the adequacy of historical fish stock allocation systems under the conditions of climate induced ecological change;
• To examine whether existing international law permits adaptive allocation mechanisms, considering specifically rules in agreements such as the UNCLOS, UNFSA, and FAO agreements;
• To assess RFMO responses to shifting fish stock distributions globally in light of climate change, comparing the responses of the NEAFC, WCPFC, CCAMLR and, as noted above, the emerging Arctic fisheries arrangements;
• To integrate climate justice and equity considerations into the analysis of fisheries allocation debates, and to consider the position of SIDS and developing coastal States;
• To develop a comprehensive Climate-Adaptive Fisheries Allocation Framework (CAFAF), which incorporates the reality of climate-induced fish stock migration, taking into account ecological, social and equity-based indicators.

1.5 Methodology

The article combines doctrinal analysis of UNCLOS, the UNFSA, RFMO constitutive instruments and relevant soft law with a structured comparative analysis of regional practice. The doctrinal analysis identifies the legal principles capable of supporting climate-adaptive allocation, while the comparative component tests how those principles are reflected, constrained or operationalised in practice (Majeed et al., 2023).

More specifically, the cases were selected according to four criteria. First, each concerns a marine region in which environmental change, changing species distribution or ecosystem uncertainty creates, or is capable of creating, pressure on conventional fisheries governance. Secondly, the cases exhibit materially different institutional responses to such pressures: the Northeast Atlantic mackerel case illustrates distributive conflict within an established regional management setting; Pacific tuna governance demonstrates the interaction between shifting stocks, allocation and the particular vulnerability of SIDS; CCAMLR provides an ecosystem-oriented institutional model in which precautionary and area-based approaches are comparatively well developed; and the Central Arctic Ocean represents an anticipatory governance model in which States have temporarily prioritised scientific uncertainty and precaution before the emergence of large-scale commercial fishing. Thirdly, the cases differ in the relative importance assigned to historical catch, zonal attachment, ecosystem protection, vulnerability and precaution. This variation permits examination of the principal considerations subsequently incorporated into the CAFAF. Fourthly, the cases encompass different geographical and developmental settings, thereby reducing the risk of deriving a proposed allocation framework exclusively from the institutional experience of a single region or category of coastal State.

The comparison is therefore functional rather than based on an assumption of formal legal equivalence. In particular, CCAMLR and the Central Arctic Ocean are not presented as allocation regimes directly equivalent to the Northeast Atlantic mackerel or Pacific tuna arrangements. CCAMLR is primarily a conservation regime with an explicit ecosystem orientation, while the Central Arctic Ocean Fisheries Agreement establishes a precautionary framework for an emerging fishery rather than an established quota-allocation system. Their inclusion serves a different comparative purpose: they provide institutional contrasts through which the capacity of fisheries governance to incorporate ecosystem protection, precaution, scientific uncertainty and anticipatory adaptation can be assessed. The cases also differ structurally in ways material to allocation: their mandates do not cover identical jurisdictional spaces; some governance arrangements address high-seas fishing while others interact directly with coastal-State EEZ rights; and the relevant resources include highly migratory tuna, straddling pelagic stocks, ecosystem-managed Antarctic resources and a potential future Arctic fishery. Allocation may consequently attach to flag-State participation, zonal presence, access within EEZs, or combinations of these considerations. CAOFA is not an RFMO; it is an intergovernmental fisheries arrangement designed to prevent unregulated high-seas fishing pending adequate scientific knowledge and, potentially, future RFMO or arrangement-based management. A comparison confined to more legally similar bodies—for example, several tuna RFMOs—could provide a tighter test of variation within a common institutional type. The deliberately heterogeneous comparison used here serves a different purpose: identifying institutional features that enable or constrain adaptation across contrasting governance architectures.

To ensure comparability despite these differences, each case is examined against the same five comparative analytical dimensions: (1) legal and institutional basis; (2) allocation or access considerations; (3) treatment of ecological change and scientific uncertainty; (4) ecosystem, vulnerability and equity considerations; and (5) institutional capacity for adjustment. These five comparative analytical dimensions provide the common framework for the case studies and are synthesised in Table 1 in Section 3.6. They are methodological criteria used to compare governance regimes and should be distinguished from the six CAFAF allocation dimensions developed in Section 4, which are substantive considerations proposed for climate-adaptive allocation. The objective is therefore not to rank four legally identical fisheries regimes, but to use structured comparison across deliberately diverse cases to identify which legal and institutional characteristics facilitate or obstruct climate-adaptive fisheries governance.

Table 1. Comparative assessment of the four case studies across the five comparative analytical dimensions introduced in Section 1.5.

Three broader conclusions follow from this comparison.

The remainder of this article is structured as follows. Section 2 examines the international legal framework; Section 3 compares the selected regional governance arrangements; Section 4 develops the CAFAF and CAAI; and Section 5 concludes.

2 International legal framework: fit for purpose?

2.1 Introduction

The international legal framework governing fisheries is anchored in UNCLOS, supplemented by the UN Fish Stocks Agreement (UNFSA), FAO instruments and a range of soft-law commitments. Collectively, these instruments establish obligations of conservation and cooperation, as well as sustainable use. These instruments, however, were drafted in an era that assumed at least a relative degree of ecological stability, which is no longer a representative paradigm. This Section therefore examines whether these instruments are fit for purpose in addressing climate-induced redistribution of fish stocks, focusing on doctrinal obligations and their interpretive potential for adaptive allocation (Boyle, 2016).

2.2 UNCLOS

2.2.1 EEZ rights and duties

UNCLOS provides the principal legal framework governing coastal-State rights and responsibilities over fisheries within the exclusive economic zone (EEZ). Its comprehensive character famously led Tommy TB Koh, President of the Third United Nations Conference on the Law of the Sea, to describe the Convention as a “constitution for the oceans” (UNCLOS, 1982; Koh, 1983). Within this framework, Article 56(1)(a) confers upon the coastal State sovereign rights for the purpose of exploring, exploiting, conserving and managing the natural resources, whether living or non-living, within its EEZ (UNCLOS, 1982, art 56(1)(a)). Articles 61 and 62 do not themselves establish those sovereign rights; rather, they regulate their exercise in relation to the conservation and utilisation of living resources. Article 61(1) requires the coastal State to determine the allowable catch, while Article 61(2) requires it, taking into account the best scientific evidence available, to adopt proper conservation and management measures to ensure that living resources are not endangered by over-exploitation (UNCLOS, 1982, arts 61(1)–(2)). Under Article 61(3), those measures must be designed to maintain or restore harvested populations at levels capable of producing maximum sustainable yield, as qualified by relevant environmental and economic factors, including the economic needs of coastal fishing communities and the special requirements of developing States (UNCLOS, 1982, art 61(3)). Article 61(4) additionally requires consideration of the effects of harvesting upon associated or dependent species (UNCLOS, 1982, art 61(4)).

Article 62 reinforces both the strength of coastal-State resource rights and the limited flexibility available within the Convention. Article 62(1) requires the coastal State to promote the objective of optimum utilisation of the living resources of its EEZ, without prejudice to Article 61. Where the coastal State lacks capacity to harvest the entire allowable catch, Article 62(2) requires access to the surplus through agreements or other arrangements (UNCLOS, 1982, art 62(1)–(2)). Article 62(3) identifies factors relevant to the terms and conditions of such surplus access, including the significance of the resources to the coastal State, developing-State requirements, and the need to minimise economic dislocation in States whose nationals have habitually fished in the zone or contributed substantially to research and stock identification (UNCLOS, 1982, art 62(3)). The habitual-fishing reference is therefore narrow: it concerns the treatment of particular third-State interests in access to surplus catch and should not be read as a general entitlement to continued access or as a general allocation rule for transboundary stocks.

The distinction between Article 62(3)’s specific surplus-access function and the broader question of transboundary allocation is important for climate-adaptive governance. Caddell notes that the provision’s reference to ‘all relevant factors may leave some interpretive flexibility as fisheries move, but that flexibility should not be overstated (Caddell, 2021). Article 62(3) neither creates a general right of access for third States nor supplies a comprehensive formula for reallocating shares when stocks redistribute. Its narrower significance is that UNCLOS does not make historical fishing the exclusive consideration even within the surplus-access context. Read together with Article 61’s requirements concerning contemporary science and environmental factors, Article 62 illustrates legal room for adaptation, while leaving the distributive architecture to more specific cooperative arrangements.

2.2.2 High seas

Beyond national jurisdiction, UNCLOS recognises fishing as one of the freedoms of the high seas under Article 87(1)(e), but that freedom is neither absolute nor unqualified. Article 116 expressly subjects the right of States for their nationals to engage in high-seas fishing to their treaty obligations, the relevant rights and interests of coastal States, and the conservation provisions contained in Articles 117–120 (UNCLOS, 1982, arts 87(1)(e), 116). Article 117 requires States to take, or cooperate in taking, measures necessary for the conservation of high-seas living resources, while Article 118 imposes an obligation upon States to cooperate in their conservation and management and, where appropriate, to cooperate in establishing subregional or regional fisheries organisations (UNCLOS, 1982, arts 117–118). Article 119 further requires conservation measures to be based upon the best scientific evidence available and to maintain or restore harvested populations at levels capable of producing maximum sustainable yield, as qualified by relevant environmental and economic factors, including the special requirements of developing States, fishing patterns and the interdependence of stocks (UNCLOS, 1982, art 119(1)).

Consequently, it would be too strong to conclude that the high-seas provisions are incapable of supporting climate-adaptive allocation. They provide a broad legal foundation based upon conservation, scientific evidence and cooperation, but leave the operationalisation of those principles largely to subsequent agreements and regional institutions. In relation to straddling and highly migratory fish stocks, the UNFSA performs an important part of this supplementary function by developing the precautionary approach, strengthening cooperative arrangements and elaborating the role of RFMOs. The central question examined in the following section is therefore whether that more detailed framework is capable of converting the adaptability permitted by UNCLOS into sufficiently responsive conservation and allocation practices under conditions of climate-driven redistribution.

UNCLOS also addresses stocks whose biological distribution crosses jurisdictional boundaries. Article 63 requires coastal States, and where relevant States fishing the adjacent high seas, to seek agreement on measures necessary to coordinate and ensure conservation of stocks occurring within two or more EEZs or straddling an EEZ and an adjacent high-seas area. Article 64 imposes a parallel duty of cooperation, directly or through appropriate international organisations, for highly migratory species listed in Annex I, both within and beyond the EEZ (UNCLOS, 1982, arts 63–64). These provisions do not prescribe allocation criteria, but they establish the cooperative legal bridge between changing stock distribution and the more detailed institutional rules subsequently developed by the UNFSA.

2.3 UN Fish Stocks Agreement

2.3.1 Precaution, cooperation and participatory rights

The UNFSA develops the general conservation and cooperation framework established by UNCLOS for straddling and highly migratory fish stocks. Article 5 requires States, inter alia, to adopt measures ensuring the long-term sustainability of such stocks, apply an ecosystem-oriented approach by considering associated and dependent species, minimise by-catch and protect biodiversity (UNFSA, 1995, art 5). Article 6 further requires States to apply the precautionary approach widely and, in doing so, to take account of uncertainties concerning stock size and productivity, reference points, fishing mortality and “existing and predicted oceanic, environmental and socio-economic conditions” (UNFSA, 1995, art 6(1)–(3)). These provisions are particularly relevant to climate-driven stock redistribution because they permit, and in important respects require, fisheries management to respond to changing environmental conditions and scientific uncertainty rather than treating existing management arrangements as ecologically fixed.

The difficulty lies less in the normative content of these provisions than in their implementation through regional fisheries institutions. Rayfuse observes that climate change poses significant challenges for RFMOs because changes in stock distribution and productivity may require conservation and management arrangements to respond to ecological conditions for which existing institutional practices were not specifically designed (Rayfuse, 2019). Her analysis highlights the gap that may arise between the adaptive potential of precautionary and ecosystem-based principles and their practical operationalisation within RFMOs, particularly where changing ecological conditions affect established fishing interests and negotiated management arrangements.

Articles 8–14 UNFSA strengthen this institutional dimension by requiring cooperation through appropriate subregional and regional fisheries management organisations or arrangements. Article 8(3) provides that States fishing for the relevant stocks on the high seas and relevant coastal States are to give effect to their duty to cooperate by becoming members of, participating in, or agreeing to apply the conservation and management measures established by the competent organisation or arrangement. Importantly, the same provision states that States having a “real interest” in the fisheries concerned may become members or participants and that the terms of participation must not preclude or discriminate against States having such an interest (UNFSA, 1995, art 8(3)). The expression ‘real interest’ is deliberately open-textured and is not defined by the Agreement. Molenaar’s detailed analysis cautions against reducing it to historical fishing alone: the concept operates within the wider duty of cooperation and must be interpreted consistently with the non-discrimination language of Article 8(3), while leaving substantial room for regional practice to determine the interests that justify participation (Molenaar, 2000). It should therefore not be characterised as automatically entrenching historical fishing patterns or excluding new entrants, although disputes over its application can themselves become distributive controversies.

The more difficult issue arises in the implementation of participatory rights once membership or participation is sought. As Serdy demonstrates in his detailed analysis of the “new entrants problem”, regional fisheries governance must reconcile the claims of existing participants with those of States seeking access to fisheries in which available fishing opportunities may already be fully or substantially allocated (Serdy, 2016). The tension therefore does not arise because Article 8 itself legally privileges historical fishing States. Rather, it can arise where RFMO allocation practices, negotiated quota shares or capacity limitations give substantial practical weight to established participation. Climate-driven redistribution may intensify this problem by creating or strengthening the interests of coastal States that previously had little participation in a particular fishery but within whose maritime zones the stock subsequently becomes more abundant.

The UNFSA also distinguishes between the general institutional function of allocating fishing opportunities and the criteria relevant to participation. Article 10(b) requires States cooperating through RFMOs or arrangements to agree, as appropriate, on “participatory rights such as allocations of allowable catch or levels of fishing effort” (UNFSA, 1995, art 10(b)). It does not, however, specify in that provision the criteria according to which such allocations must be determined. Article 11 is the more relevant provision where new members or participants are concerned. It identifies a range of factors to be taken into account in determining the nature and extent of participatory rights, including the status of the stocks and existing fishing effort, the respective interests, fishing patterns and fishing practices of new and existing participants, contributions to conservation and scientific research, the needs of coastal fishing communities dependent mainly upon the stocks, the needs of coastal States whose economies are overwhelmingly dependent upon living marine resources, and the interests of developing States in whose areas of national jurisdiction the stocks also occur (UNFSA, 1995, art 11).

Article 7 performs a different function and should not be treated as an allocation provision. It concerns the compatibility of conservation and management measures established for the high seas and for areas under national jurisdiction in respect of the same straddling or highly migratory stocks. In determining compatible measures, States are required to take account of factors including previously agreed measures, measures adopted by coastal States within their areas of national jurisdiction, previously agreed measures adopted for the high seas, the biological unity and distribution of the stocks, the respective dependence of coastal and fishing States upon them, and the need to avoid harmful impacts upon the living marine resources as a whole (UNFSA, 1995, art 7(2)). These considerations may be relevant to climate adaptation because stock distribution and dependence can change over time, but Article 7 does not itself establish criteria for the allocation of fishing opportunities.

The UNFSA framework is therefore more adaptable than an account centred exclusively upon historical catch would suggest. It provides legal space for new participants, recognises a range of interests beyond established fishing history, and does not prescribe historical catch as the controlling criterion for allocation. The principal challenge for climate-adaptive allocation lies instead in how RFMOs translate these broadly framed treaty principles into concrete participatory rights and quota arrangements (UNFSA Review Conference, 2006; UNFSA Review Conference, 2016; United Nations General Assembly (UNGA), 2004). Where institutional practice gives predominant weight to established fishing patterns, the difficulty is one of implementation and distributive choice rather than an inherent rigidity in the text of the UNFSA itself.

2.4 FAO instruments and related environmental and climate frameworks

The legal framework relevant to climate-adaptive fisheries governance is supplemented by a range of FAO instruments and broader biodiversity and climate regimes. These instruments should not be treated as establishing an alternative system of fisheries allocation. Nor do they generally prescribe how relative quota shares should be distributed among States. Their relevance to the present analysis is more specific: they reinforce principles of precaution, ecosystem sustainability, scientific adaptation, enforcement, biodiversity resilience and vulnerability that can inform the exercise of the discretion left to States and RFMOs under UNCLOS and the UNFSA. They therefore provide supplementary normative support for climate-adaptive allocation while leaving the actual determination of participatory rights and quota shares to the applicable fisheries institutions.

The 1995 FAO Code of Conduct for Responsible Fisheries is a voluntary instrument establishing international principles and standards for responsible fisheries management (FAO, 1995). It requires States and fisheries management organisations to apply the precautionary approach widely and expressly directs decision-makers to take account of uncertainty concerning stock size and productivity, the distribution of fishing mortality and climatic, environmental, social and economic conditions (FAO, 1995). The Code is relevant to climate-adaptive allocation not because it determines how fishing opportunities should be divided, but because it supports the proposition that management decisions should be based upon changing scientific and environmental conditions rather than solely upon historical patterns of exploitation. The FAO International Guidelines on Bycatch Management and Reduction of Discards similarly provide voluntary guidance for reducing the ecosystem effects of fishing and reinforce the broader ecosystem-oriented constraints within which any allocation system must operate (FAO, 2011; FAO, 2003).

United Nations (1992) International climate law provides an additional normative context. Article 7 of the Paris Agreement establishes the global goal on adaptation of enhancing adaptive capacity, strengthening resilience and reducing vulnerability to climate change (Paris Agreement, 2015, art 7(1)). As with the biodiversity instruments, this provision does not create fisheries allocation rights and should not be treated as directly determining quota shares. Its relevance arises because climate-driven stock redistribution is itself an adaptation problem: fisheries institutions must determine how conservation and access arrangements should respond when climatic changes alter stock distribution, productivity and the dependence of coastal communities upon fisheries. The adaptation framework of the Paris Agreement therefore reinforces the legitimacy of interpreting discretionary fisheries-management mechanisms in ways that take account of vulnerability, resilience and changing climatic conditions.

Taken together, these instruments reveal a consistent distinction between normative adaptation and distributive allocation. The FAO Code of Conduct and the FAO Guidelines considered above reinforce precautionary, ecosystem-sensitive and scientifically responsive fisheries management, while the Paris Agreement supplies a broader normative context of adaptation, resilience and vulnerability. None independently determines how a climate-redistributed transboundary stock should be divided among States. Their collective relevance lies instead in identifying considerations that may legitimately inform the allocation discretion exercised through RFMOs and other cooperative arrangements. They therefore support, rather than themselves constitute, the legal foundation for the climate-adaptive allocation framework developed later in this article.

2.5 Conclusion

The analysis in this Section suggests that the international legal framework governing transboundary fisheries is more capable of accommodating climate-driven stock redistribution than a characterisation based upon legal rigidity would imply. UNCLOS and the UNFSA contain a range of provisions capable of responding to changing scientific and environmental conditions. These include obligations concerning the use of the best scientific evidence available, conservation and sustainable use, cooperation, the precautionary approach, ecosystem considerations and the recognition of environmental, economic and developmental factors. Neither instrument therefore requires fisheries management arrangements to remain fixed when the geographical distribution, productivity or accessibility of stocks changes.

The principal limitation is instead institutional and distributive. Although UNCLOS and the UNFSA permit conservation measures and cooperative arrangements to adapt, they do not themselves prescribe a comprehensive mechanism for determining how relative fishing opportunities should be redistributed when climate-driven stock shifts alter the relationship between States and a shared fishery. In particular, the treaties do not compel States or RFMOs to revise historically established allocation arrangements merely because the geographical distribution of a stock has changed. The existence of legal flexibility therefore does not necessarily produce institutional adaptation.

This distinction is important. The problem identified in this article is not that international fisheries law is incapable of being interpreted in a climate-responsive manner. On the contrary, the relevant treaty provisions provide substantial normative space for adaptive management and, through regional cooperation, for adaptive allocation. The difficulty is that the framework frequently leaves the translation of those principles into concrete allocation decisions to States and regional fisheries institutions, where consensus requirements, established participation patterns, negotiated expectations and distributive conflicts may inhibit adjustment.

The supplementary instruments considered in this Section reinforce rather than alter this conclusion. FAO instruments elaborate precautionary and ecosystem-based management principles; the FAO Code of Conduct and Guidelines reinforce precautionary and ecosystem-sensitive management; and international climate law provides a wider normative context of adaptation, resilience and vulnerability. None of these instruments independently establishes a formula for reallocating fishing opportunities in response to climate-driven stock redistribution. Together, however, they strengthen the legal and policy basis upon which adaptive fisheries institutions may act.

The central question is therefore no longer whether international law contains principles capable of supporting climate-adaptive fisheries governance, but whether those principles are effectively operationalised in regional decision-making. The following Section examines this question comparatively through the Northeast Atlantic mackerel dispute, Pacific tuna governance, CCAMLR and the emerging Central Arctic Ocean fisheries regime, focusing on the institutional conditions that facilitate or obstruct the translation of legal flexibility into adaptive conservation, access and allocation practices.

3 Comparative RFMO analysis

3.1 Introduction

Regional Fisheries Management Organisations (RFMOs) are the institutional backbone of international fisheries governance. These organisations operationalise UNCLOS and UNFSA obligations, adopting conservation and management measures (CMMs) for straddling and highly migratory stocks (UNFSA, 1995, arts 8, 10). The performance of these RFMOs in adapting to climate-induced redistribution has, however, been uneven, and this Section will now compare three major RFMOs, the NEAFC, the WCPFC and the CCAMLR, alongside emerging Arctic governance, to assess institutional barriers and adaptive practices.

RFMOs constitute the principal mechanisms through which the conservation, access and allocation obligations contained in UNCLOS and UNFSA are implemented in practice. Their responses to climate-induced ecological change are, however, far from uniform. This Section examines four deliberately contrasting cases: the Northeast Atlantic mackerel fishery, Western and Central Pacific tuna fisheries, CCAMLR and the emerging Central Arctic Ocean fisheries regime.

These cases should not be understood as four formally equivalent RFMOs or allocation systems. Rather, they represent four distinct governance situations through which different dimensions of climate adaptation can be examined. The Northeast Atlantic mackerel dispute represents an established fishery experiencing redistribution-driven allocation conflict; Pacific tuna governance represents an established highly migratory fishery in which redistribution interacts with development, food security and the vulnerability of SIDS; CCAMLR represents an ecosystem-centred conservation regime with comparatively strong precautionary and scientific features; and the Central Arctic Ocean represents an anticipatory regime governing a potential future fishery under conditions of substantial scientific uncertainty.

The comparative value of these cases lies precisely in this institutional variation. A comparison confined to legally identical RFMOs would demonstrate differences in implementation but would provide a narrower basis from which to identify the institutional characteristics necessary for climate adaptation. The present comparison instead asks how different governance architectures respond to a common underlying problem: the increasing incompatibility between relatively static legal and allocation arrangements and dynamic marine ecosystems.

Accordingly, each case is assessed through the same five questions. First, what is the legal and institutional basis of the regime? Secondly, which considerations principally determine allocation, access or management decisions, including historical catch and zonal attachment? Thirdly, how does the regime accommodate changing stock distribution, scientific uncertainty and ecological change? Fourthly, to what extent are ecosystem sustainability, vulnerability, food security and distributive equity incorporated into decision-making? Fifthly, what institutional mechanisms permit or impede adjustment when ecological conditions change?

Applying these common analytical dimensions makes it possible to distinguish differences attributable merely to the legal nature of the regimes from differences that reveal broader strengths or weaknesses in adaptive governance. The analysis therefore proceeds from two established allocation settings—the Northeast Atlantic and Western and Central Pacific—to the ecosystem-oriented CCAMLR model and finally to the precautionary and anticipatory Central Arctic Ocean regime. Section 2.6 then draws these findings together through a structured comparative synthesis.

3.2 North East Atlantic Fisheries Commission

The North-East Atlantic fisheries regime combines the NEAFC Convention’s high-seas regulatory mandate with coastal-State arrangements for stocks that occur both within EEZs and in the Regulatory Area. The Convention authorises recommendations concerning fisheries in the Convention Area and requires the Commission, in exercising its functions, to seek consistency with coastal-State measures for stocks occurring within national jurisdiction and the adjacent high seas (NEAFC Convention, 1980). This structure matters because the mackerel allocation dispute is not simply an internal NEAFC quota exercise: allocation among coastal States is negotiated alongside NEAFC’s high-seas management role, and changing zonal attachment can alter the bargaining positions of States as stock distribution changes.

The Northeast Atlantic mackerel dispute illustrates the resulting distributive tension. As mackerel distribution expanded north-westwards and its presence increased in Icelandic and Faroese waters, those States sought larger shares while other participants emphasised established fishing patterns and negotiated expectations. The result was not institutional inaction in the simple sense. States repeatedly attempted to renegotiate arrangements, but disagreement over the weight to be given to contemporary distribution, historical participation and other allocation claims produced unilateral quota setting and periods of over-allocation (Østhagen et al., 2020). The case therefore demonstrates an active but conflict-prone form of adaptation: scientific evidence of redistribution can enter negotiations without generating agreement on how the distributive consequences should be shared (Jensen et al., 2015).

For present purposes, the important point is that scientific advice and stock assessment can reveal ecological change more readily than the allocation process can translate that change into revised shares. Ecosystem considerations may strengthen the conservation context, but they are not a necessary condition for adaptive allocation. What matters more directly is whether updated science on distribution and abundance is institutionally connected to procedures capable of reopening participatory shares without making every adjustment dependent upon ad hoc bargaining. The NEAFC/mackerel experience thus supports the paper’s broader distinction between scientific adaptability and distributive adaptability.

In its allocation practices, the NEAFC has relied on historical catch and zonal attachment in quota allocation (UNFSA, 1995, art 7). The Northeast Atlantic mackerel dispute illustrates the fragility of this system. When mackerel stocks shifted into Icelandic and Faroese waters due to warming seas, these States demanded larger quotas, which existing members then resisted, citing historical allocations. The dispute escalated into unilateral fishing and collapse of cooperation (Østhagen et al., 2020). Østhagen argues convincingly here that the NEAFC’s reliance on historical allocation created rigidity, preventing adaptation to ecological change, showing how the rigidity and self-interest of RFMO members can result in the failure to adapt to changing requirements.

3.3 Western and Central Pacific Fisheries Commission (WCPFC)

The WCPFC manages highly migratory tuna stocks in the Western and Central Pacific, with membership including major fishing States and Pacific Island countries (Churchill, 2007). Its mandate reflects UNFSA obligations and incorporates precautionary and ecosystem approaches (WCPFC Convention, 2000). Recent WCPFC practice also shows that the Commission is no longer appropriately described simply as having failed to engage with climate change. Climate change has become a standing agenda item across WCPFC bodies, a Climate Change Workplan for 2024–2027 was adopted, and subsequent work has developed ecosystem and climate indicators and a framework for assessing the vulnerability of conservation and management measures to climate impacts (WCPFC, 2024, 2025, 2026). These initiatives remain primarily directed at understanding and integrating climate risk into management rather than renegotiating allocation shares, but they demonstrate meaningful institutional progression since earlier criticism of the Commission’s response.

Rayfuse’s earlier criticism remains useful as a baseline for assessing the gap between precautionary obligations and climate-responsive allocation (Rayfuse, 2019), but subsequent practice requires a more qualified assessment. The WCPFC’s climate workplan, climate and ecosystem indicators, and climate-change vulnerability assessment process indicate increasing institutional attention to climate impacts (WCPFC, 2024, 2025, 2026). They do not yet amount to a settled mechanism for reallocating fishing opportunities as tuna distribution changes. This makes the WCPFC materially different from the Northeast Atlantic mackerel dispute: the latter has already generated acute renegotiation of competing allocation claims, whereas the WCPFC is still developing the scientific and institutional machinery through which future climate-related distributional pressures may be addressed.

Allocation within the WCPFC has nevertheless been contentious. Developed fishing States have often emphasised historical catch, while Pacific Island States have stressed zonal attachment and developmental needs (Cheung et al., 2010). Climate change may intensify these tensions as tuna distributions shift, potentially reducing catches in some SIDS (Lehodey et al., 1997; Cheung et al., 2010). More recent Pacific-focused research sharpens the distributive stakes. Bell et al. project that climate-driven movement of tuna from the EEZs of tuna-dependent Pacific SIDS toward the high seas could reduce purse-seine catches, access-fee revenue and government revenue, making redistribution an issue of fiscal capacity and climate justice as well as food security (Bell et al., 2021). The existing Parties to the Nauru Agreement Vessel Day Scheme provides some capacity to smooth spatial variability within participating EEZs but does not by itself solve the longer-term problem of biomass shifting from those EEZs to high-seas areas.

The WCPFC Convention is particularly significant for the present analysis because, unlike UNCLOS and the UNFSA, it expressly identifies a detailed range of considerations relevant to the allocation of fishing opportunities. Article 10(3) provides that, in developing criteria for the allocation of total allowable catch or total level of fishing effort, the Commission must take into account, inter alia, the status of the stocks and existing fishing effort; the respective interests, past and present fishing patterns and fishing practices of participants; the extent of the catch taken and fishing effort exercised within areas under national jurisdiction; the needs of small island developing States and other participating territories and possessions; the respective contributions of participants to conservation and management, data collection and scientific research; the needs of coastal communities principally dependent upon the stocks; the special circumstances of States surrounded by EEZs of other States; the geographical situation of small island developing States composed of non-contiguous island groups; and any other relevant factors (WCPFC Convention, 2000, art 10(3)).

Article 10(3) is important because it demonstrates that allocation under the WCPFC Convention is not legally reducible to historical catch. Past and present fishing patterns are expressly relevant, but they constitute only one element within a broader and potentially adaptive set of considerations. Of particular significance for climate-driven stock redistribution are the Convention’s express references to catch and fishing effort within areas under national jurisdiction, the needs of small island developing States, dependence of coastal communities upon the relevant stocks, contributions to conservation and scientific research, and the residual category of “any other relevant factors”. These criteria provide substantial legal space for the Commission to take account of changes in stock distribution and their socio-economic consequences, even though Article 10(3) does not expressly identify climate change or climate-driven redistribution as an allocation criterion.

The difficulty examined in this article therefore lies not in the absence of potentially adaptive allocation criteria from the WCPFC Convention itself, but in how these criteria are weighted and operationalised in practice. Article 10(3) does not establish a hierarchy among the listed considerations or prescribe a mathematical formula for converting them into relative allocation shares. Consequently, the Convention provides a comparatively broad normative framework for adaptive allocation while leaving the distributive balance among historical participation, contemporary geographical interests, developing-State needs and other relevant considerations to negotiation within the Commission. This distinction between the legal availability of adaptive criteria and their institutional operationalisation is central to assessing the WCPFC’s response to climate-driven redistribution.

3.4 Commission for the Conservation of Antarctic Marine Living Resources

The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) was established pursuant to the 1980 Convention on the Conservation of Antarctic Marine Living Resources (CAMLR Convention), which was negotiated within the broader framework of the Antarctic Treaty System and entered into force in 1982 (CAMLR Convention, 1980). The Convention is particularly significant for the present analysis because its conservation mandate is explicitly ecosystem-oriented. Article II defines the objective of the Convention as the conservation of Antarctic marine living resources, while clarifying that “conservation” includes rational use. It further requires harvesting and associated activities to maintain ecological relationships between harvested, dependent and related populations and to prevent, or minimise the risk of, changes to the marine ecosystem that are not potentially reversible over two or three decades, taking account of available knowledge concerning harvesting, associated activities and environmental change (CAMLR Convention, 1980, art II(1)–(3)). These provisions distinguish CCAMLR from fisheries regimes focused more narrowly upon the management of individual target stocks and provide a comparatively strong legal basis for ecosystem-sensitive and adaptive management. The relevance of this ecosystem mandate to climate-adaptive fisheries allocation is indirect but significant. The CAMLR Convention does not establish a general formula for reallocating fishing opportunities in response to climate-driven stock redistribution. Article II nevertheless demonstrates that fisheries management under the Convention is expressly required to consider ecological relationships and environmental change rather than treating the geographical and biological characteristics of fisheries as fixed. CCAMLR therefore provides a useful comparator for assessing whether ecosystem-oriented and precautionary institutional structures can translate ecological change into adaptive management decisions.

Despite its strong ecosystem mandate, CCAMLR has encountered significant institutional difficulties in expanding its system of marine protected areas (MPAs), particularly because substantive decisions are generally dependent upon consensus among Members (CAMLR Convention, 1980, art XII(1)). This difficulty should not be understood as demonstrating a weakness in the scientific foundations of CCAMLR’s ecosystem approach. Kock’s account of CCAMLR management illustrates the development of a precautionary and ecosystem-based system in which management extends beyond individual target species to consider dependent and related species and wider ecosystem dynamics (Kock, 2000). The more significant constraint arises in translating scientific analysis into collectively agreed conservation measures where Members hold divergent interests. Recent analysis of CCAMLR’s consensus practice demonstrates that proposals concerning MPAs and responses to climate impacts have proved particularly difficult to adopt, and that measures perceived as affecting existing or prospective fishing interests may encounter sustained opposition (Goldsworthy, 2022). Li and Yang similarly identify international cooperation and the accommodation of conservation and fishing interests as central challenges in the development of Southern Ocean MPAs (Li and Yang, 2018).

At the same time, CCAMLR’s MPA framework illustrates an important form of ecological adaptation. MPAs can provide reference areas in which scientists compare restricted or protected areas with areas open to fishing, thereby assisting the assessment of ecosystem change and the effects of climate change (CCAMLR, n.d.). CCAMLR therefore provides a potentially valuable model for other regional fisheries institutions insofar as it integrates ecosystem protection, scientific monitoring and environmental change into spatial management. Its experience nevertheless also demonstrates the distinction between normative capacity and institutional implementation that runs throughout this article: a strong ecosystem and precautionary mandate can provide the legal and scientific foundations for climate-responsive management, but consensus-based decision-making may impede or delay the translation of those foundations into new conservation measures. For climate-adaptive fisheries governance, CCAMLR consequently illustrates both the value of embedding ecological change within institutional decision-making and the importance of mechanisms capable of converting scientific information into timely collective action.

The CCAMLR case therefore demonstrates that a comparatively strong ecosystem and environmental-change mandate does not automatically produce institutional adaptation. The CAMLR Convention provides substantial legal capacity for ecologically responsive management, but the implementation of that capacity remains dependent upon institutional decision-making, including the ability of members to reach consensus. For the purposes of climate-adaptive allocation, CCAMLR consequently illustrates both the value of embedding ecological change within the governing legal mandate and the limitations of relying upon normative flexibility without corresponding institutional mechanisms capable of translating scientific change into timely management decisions.

3.5 Emerging Arctic governance

The Central Arctic Ocean Fisheries Agreement (CAOFA) represents a particularly significant example of anticipatory and precautionary fisheries governance. Rather than waiting for a commercially significant fishery to develop before establishing conservation measures, the Agreement seeks to prevent unregulated fishing in the high seas portion of the Central Arctic Ocean while scientific knowledge concerning the region’s fish stocks and ecosystems remains limited (CAOFA, 2018, art 2). The Agreement nevertheless does not establish a permanent prohibition on commercial fishing. Instead, it creates an interim regime under which commercial fishing may occur only pursuant to conservation and management measures adopted by an appropriate regional or subregional fisheries management organisation or arrangement, or pursuant to interim measures established by the Parties under the Agreement (CAOFA, 2018, art 3(1)). It also establishes a Joint Program of Scientific Research and Monitoring intended to improve knowledge of the ecosystems and determine whether fish stocks might support sustainable commercial fisheries (CAOFA, 2018, art 4).

The significance of this arrangement should therefore be characterised more carefully than as a merely temporary moratorium. The CAOFA initially remains in force for sixteen years and is thereafter automatically extended for successive five-year periods unless a Party objects to an extension (CAOFA, 2018, art 13). The Agreement can therefore extend beyond its initial term, but its durability is politically contingent because continuation can be blocked by a Party objecting to an extension. It nevertheless establishes a precautionary regime that deliberately leaves open the possibility of future commercial fishing once sufficient scientific information and appropriate conservation and management arrangements exist. This structure is both a strength and a limitation from the perspective of climate adaptation. It allows governance to develop in response to emerging scientific knowledge rather than predetermining a permanent regulatory outcome, but it also means that the future management of commercially viable fisheries may ultimately require additional institutional arrangements. Scholarship on the CAOFA accordingly emphasises that the Agreement forms part of an evolving Arctic Ocean governance complex and expressly contemplates the possible future establishment of one or more regional fisheries management organisations or arrangements if commercial fishing becomes viable (Vylegzhanin et al., 2020). The extension mechanism therefore reproduces, in a different form, the consensus-related vulnerability identified elsewhere in this article: anticipatory design can postpone distributive conflict, but cannot remove the political capacity of States to resist continuation or future institutional development.

For the purposes of climate-adaptive fisheries governance, the Central Arctic Ocean case therefore provides an important contrast with fisheries in which allocation arrangements developed only after substantial fishing interests had already become established. The CAOFA seeks to create scientific and institutional foundations before large-scale commercial exploitation begins. It does not yet resolve the future distributive question of how fishing opportunities should be allocated if commercially significant stocks emerge or increasingly redistribute into the high seas portion of the Central Arctic Ocean. Its principal contribution is instead anticipatory: it creates time and a cooperative scientific process within which future conservation and allocation arrangements can be developed before historical fishing patterns become entrenched. The Arctic example therefore demonstrates the potential value of precautionary governance while simultaneously illustrating that scientific adaptation must ultimately be accompanied by institutional mechanisms capable of governing participation and allocation if new fisheries emerge.

3.6 Comparative synthesis: four models of adaptive capacity

The four cases reveal not a single model of fisheries governance but a continuum of approaches to ecological change. Their legal and institutional differences make direct comparison of quota rules inappropriate, but comparison across the five comparative analytical dimensions introduced in Section 1.5 and applied throughout Section 3 reveals several recurring patterns relevant to the development of CAFAF. Table 1 summarises the results of that structured comparison and shows how each governance setting performs a different analytical function in identifying the institutional features that enable or constrain climate adaptation.

First, historical allocation becomes particularly problematic where ecological redistribution is already occurring within an established commercial fishery. The Northeast Atlantic mackerel case demonstrates this most directly. When the geographical distribution of a stock changes but quota expectations remain anchored in earlier fishing patterns, the divergence between ecological presence and institutional entitlement can undermine cooperation. Pacific tuna governance demonstrates a related problem but adds a distributive dimension: changes in stock distribution may impose particularly severe consequences upon States whose economies, public revenues and food security depend heavily upon fisheries. These two cases therefore support the inclusion of contemporary stock distribution, historical participation, climate vulnerability and food-security dependence as distinct considerations in the design of an adaptive allocation framework.

Secondly, the comparison demonstrates that adaptation concerns more than the redistribution of quota. CCAMLR illustrates the importance of ecosystem-level management, scientific monitoring and precaution, even though its legal and institutional purposes differ from the allocation regimes examined in the first two cases. Its relevance to the design of an adaptive allocation framework therefore lies not in providing a transferable allocation formula but in demonstrating that fisheries governance can institutionalise ecological considerations as continuing constraints upon exploitation. At the same time, the difficulties created by consensus decision-making illustrate that progressive substantive mandates do not necessarily produce adaptive outcomes where institutional procedures permit political disagreement to delay action.

Thirdly, the Central Arctic Ocean case demonstrates the value of anticipatory governance. Unlike the mackerel and tuna cases, it does not involve the redistribution of a mature quota among States with deeply entrenched historical expectations. Its significance lies precisely in the fact that governance mechanisms have been established before large-scale commercial exploitation develops. This provides an important contrast with reactive adaptation in established fisheries. Once economic expectations, fleet investments and historical catch records become embedded, subsequent redistribution becomes politically more difficult. A climate-adaptive framework should therefore not merely respond to ecological change after distributive conflict arises; it should incorporate scientific review and mechanisms for future adjustment before allocation patterns become institutionally entrenched.

The cases consequently perform complementary rather than identical functions within the analysis. Mackerel demonstrates the costs of allocation rigidity; Pacific tuna exposes the distributive and climate-justice consequences of redistribution; CCAMLR demonstrates the potential and institutional limits of ecosystem-oriented governance; and the Central Arctic Ocean illustrates precautionary and anticipatory governance before historical allocation becomes entrenched. Taken together, the findings generated through the five comparative analytical dimensions provide the comparative foundation for the six CAFAF allocation dimensions developed in Section 4: Contemporary Stock Distribution (CSD), Historical Participation (HP), Ecosystem Sustainability Performance (ESP), Climate Vulnerability (CV), Food-Security and Developmental Dependence (FSD), and Equitable Allocation Need (EAN). The five comparative analytical dimensions are therefore the methodology for comparing the case studies; the six CAFAF allocation dimensions are the substantive criteria proposed for allocation decisions.

The comparison also demonstrates why no single existing regime provides a complete model for climate-adaptive allocation. The framework developed in the following section therefore does not seek to transplant one of these institutional arrangements into other regions. Instead, it synthesises their respective lessons into a common framework: ecological responsiveness from the mackerel experience; attention to vulnerability and developmental dependence from Pacific tuna governance; ecosystem sustainability and precaution from CCAMLR; and anticipatory review and scientific uncertainty management from the Central Arctic Ocean. The comparative analysis thus provides the empirical and institutional bridge between the deficiencies identified in Sections 2–4 and the operational allocation architecture proposed in Section 5.

4 Climate-adaptive fisheries allocation framework

4.1 Climate-adaptive fisheries allocation framework

The Climate-Adaptive Fisheries Allocation Framework (CAFAF) is the article’s proposed institutional design for climate-responsive allocation. It comprises three connected elements: (1) six substantive CAFAF allocation dimensions—Contemporary Stock Distribution (CSD), Historical Participation (HP), Ecosystem Sustainability Performance (ESP), Climate Vulnerability (CV), Food-Security and Developmental Dependence (FSD), and Equitable Allocation Need (EAN)—derived from the comparative findings in Section 3; (2) a procedural cycle for agreeing indicators, data, weights, review periods and safeguards within the competent RFMO or arrangement; and (3) the Climate-Adaptive Allocation Index (CAAI), a decision-support tool that can operationalise the six allocation dimensions after those political and institutional choices have been made. CAFAF is therefore broader than the CAAI: the framework structures both the negotiation and review process, while the index is only its quantitative component. Rather than replacing existing international fisheries law, CAFAF seeks to operationalise principles already embedded within UNCLOS, the UNFSA and contemporary fisheries governance.

CAFAF is built upon six interrelated allocation dimensions. First, Contemporary Stock Distribution (CSD) measures present geographical distribution and relative abundance. CSD should inform allocation because persistent redistribution can weaken the connection between historically negotiated shares and the contemporary location of the resource. It should not, however, create an automatic rule that quota follows fish. Such a rule could transfer climate risk almost entirely to coastal States losing stocks, including highly fisheries-dependent SIDS. CSD is therefore one dimension to be balanced against historical participation, vulnerability, developmental dependence and equity, with stabilisation safeguards limiting abrupt redistribution (Cheung et al., 2010; Bell et al., 2021; Palacios-Abrantes et al., 2025).

Secondly, Historical Participation (HP) recognises verified past participation and the investments associated with it. Its function is to protect continuity and reduce abrupt dislocation, not to equate historical catch with every form of economic dependence. Flag-State harvesting history is distinct from coastal-State dependence on access fees paid by foreign fleets. The latter is better captured through Food-Security and Developmental Dependence (FSD) and, where losses are not adequately reflected there, Equitable Allocation Need (EAN). Historical participation should therefore remain relevant but should not operate as the presumptively dominant criterion.

Thirdly, Ecosystem Sustainability Performance (ESP) assesses the performance of participating States in meeting applicable conservation and management obligations and operates as a sustainability safeguard on allocation. It is not a score for the biological condition of the stock itself, which is principally addressed when the TAC and conservation measures are set. At allocation stage, ESP may use measurable indicators such as compliance with quotas, by-catch and discard rules, reporting and data-submission obligations, monitoring and enforcement requirements, and contributions to agreed scientific programmes (UNFSA, 1995, arts 5–6; Juan-Jordá et al., 2018). Ecosystem orientation is therefore one legally relevant component of adaptive governance, not a necessary condition for adaptive allocation. Scientific advice, stock assessment and distribution data can support reallocation even in regimes without a strong ecosystem mandate; ESP instead ensures that distributive adaptation remains bounded by conservation performance.

Fourthly, Climate Vulnerability (CV) measures exposure and adaptive capacity in relation to climate-driven changes affecting the fishery, particularly where SIDS and other climate-vulnerable coastal States face disproportionate impacts (Blasiak et al., 2017). Fifthly, Food-Security and Developmental Dependence (FSD) captures identifiable dependence on the fishery, including dietary protein, employment, coastal livelihoods, domestic value addition, government revenue and fishing-access fees. Bell et al. demonstrate why access-fee dependence is especially important for tuna-dependent Pacific SIDS, but the indicator is not region-specific and may apply wherever coastal States derive material public revenue or development benefits from foreign fishing access (Bell et al., 2021; Golden et al., 2016).

FSD is analytically related to equity but is kept as a separate dimension because it captures measurable forms of dependence that can be specified ex ante rather than left to residual equitable discretion. Separating FSD from EAN reduces the burden placed on an open-ended equity category and makes visible the particular economic functions that fisheries perform for different States.

Finally, Equitable Allocation Need (EAN) is a cross-cutting but residual dimension in a defined sense: it addresses demonstrable distributive disadvantages not already captured by CSD, HP, ESP, CV or FSD. Residual does not mean marginal. It prevents double counting while preserving space to address, for example, disproportionate climate-related losses, genuine new-entrant disadvantages, or other distributional effects that the more specific dimensions fail to capture (Gray, 2024; Serdy, 2016). Because EAN is potentially contestable, its indicators and evidentiary thresholds should be agreed ex ante and reasons should be published. Like every CAAI dimension, EAN remains subject to negotiation and cannot circumvent RFMO consensus requirements.

These six CAFAF allocation dimensions are translated into an operational decision-making architecture through the Climate-Adaptive Allocation Index (CAAI). The distinction between CAFAF and CAAI is important. CAFAF constitutes the overarching normative and institutional framework, whereas the CAAI is the decision-support instrument through which the six allocation dimensions are organised, measured and compared in individual allocation exercises.

4.2 Climate-adaptive allocation index

The Climate-Adaptive Allocation Index (CAAI) is therefore an operational component of CAFAF rather than synonymous with the framework itself. Its purpose is to translate the six principles identified above into a transparent and reproducible structure capable of informing RFMO allocation decisions.

The CAAI should also be distinguished from the scientific process by which the total allowable catch (TAC) is established. It does not determine how much of a stock may sustainably be harvested. That question remains governed by scientific stock assessment, applicable conservation obligations, precautionary reference points and ecosystem considerations under UNCLOS and the UNFSA (UNCLOS, arts 61–62; UNFSA, arts 5–6) (Kerr et al., 2026; Marshall et al., 2026; Punt et al., 2021). The CAAI operates only after the permissible TAC has been determined and addresses the separate distributive question of how that TAC should be allocated among eligible participating States.

4.2.1 Formal structure and weighting of the CAAI

For a particular stock, assessment period and participating State i, the CAAI may be expressed as a weighted composite index:

The formal expression should not obscure the institutional difficulty of reaching agreement on an allocation formula. Long-running negotiations in the Indian Ocean Tuna Commission’s Technical Committee on Allocation Criteria demonstrate that even without climate change, States can disagree for years over baselines, coastal-State interests, historical catch, developing-State needs and the distributive consequences of alternative criteria (IOTC, 2024, 2025, 2026; Indian Ocean Tuna Commission (IOTC), 2011; IOTC, 2021; IOTC, 2026a; IOTC, 2026b; Indian Ocean Tuna Commission Secretariat, 2026). The CAAI therefore cannot bypass consensus-based decision-making. Its value is narrower: once members have negotiated the relevant criteria and safeguards, it can make the consequences of those choices more transparent, reproducible and open to sensitivity testing. Earlier work on tuna allocation likewise illustrates how allocation models can generate materially different distributive outcomes for Pacific Island States (Parris, 2010).

CAAI(i)=w1S1(i)+w2S2(i)+w3S3(i)+w4S4(i)+w5S5(i)+w6S6(i)

where:

S₁ = Contemporary Stock Distribution (CSD)

S₂ = Historical Participation (HP)

S₃ = Ecosystem Sustainability Performance (ESP)

S₄ = Climate Vulnerability (CV)

S₅ = Food-Security and Developmental Dependence (FSD)

S₆ = Equitable Allocation Need (EAN)

and:

Σwk=1The use of a weighted composite structure follows established methodology for composite indicators, under which conceptually distinct variables are first rendered comparable through normalisation and subsequently combined through an explicitly defined weighting and aggregation rule (OECD and European Commission JRC, 2008, pp. 13–31).

Each component would be transformed into a standardised score ranging from 0 to 1. For continuous variables, a basic min–max transformation may be employed:

Sk(i)=[Xk(i)−Xk(min)]/[Xk(max)−Xk(min)]Where a higher raw value represents a less favourable outcome, the direction of the indicator should be reversed:

Sk(i)=[Xk(max)−Xk(i)]/[Xk(max)−Xk(min)]Min–max normalisation provides an established means of making indicators measured on different scales comparable within a composite index (OECD and European Commission JRC, 2008, pp. 83–88). The substantive direction of every indicator should therefore be specified ex ante, and normalisation should ordinarily be undertaken separately for each stock and assessment cycle.

As a neutral starting point, the model assigns equal weight to the six components:

w1=w2=w3=w4=w5=w6=1/6≈0.167Equal weighting is adopted as a transparent normative baseline rather than as a claim that all six considerations are necessarily of identical importance in every fishery. The present analysis does not provide an empirical basis for determining, for example, that contemporary stock distribution should count precisely twice as much as climate vulnerability or food-security dependence. Since weighting choices can materially influence the results of a composite indicator, differentiated weights without empirical calibration could create an appearance of mathematical precision unsupported by the underlying analysis (OECD and European Commission JRC, 2008, pp. 89–100).

The weights should not, however, be immutable. An RFMO may adopt differentiated weights where the ecological or socio-economic characteristics of a particular fishery justify doing so. Any departure from equal weighting should satisfy three safeguards: it should be supported by a reasoned scientific or policy justification; its distributive consequences should be tested through sensitivity analysis; and the weights should be adopted and published before the relevant allocation calculation is conducted. Sensitivity analysis is especially important because changes in weighting, normalisation, aggregation and missing-data treatment can materially affect the resulting scores or rankings (OECD and European Commission JRC, 2008, pp. 117–131).

Once the CAAI score has been calculated for each eligible State, provisional quota shares may be derived as follows:

q(i)=CAAI(i)/ΣCAAI(j)and:

Q(i)=TAC×q(i)where q(i) represents the proportional allocation share of State i, Q(i) its resulting quantity of catch, and ΣCAAI(j) the aggregate CAAI scores of all eligible participating States.

The resulting quota should be understood as a provisional allocation generated by the framework rather than an automatic legal entitlement. Final authority would remain with the competent RFMO. However, any material departure from the index-generated allocation should be accompanied by reasons, thereby increasing transparency and constraining purely ad hoc distributive bargaining.

4.2.2 Indicator definitions, measurement and data sources

The six allocation dimensions require indicators that are sufficiently precise to permit measurement but sufficiently flexible to accommodate differences between stocks and regional institutions.

Contemporary Stock Distribution (CSD) should measure the mean proportion of assessed stock biomass geographically associated with the relevant State’s EEZ or management area during the assessment period. RFMO scientific committees, ICES or comparable bodies, standardised surveys, tagging data and validated species-distribution models could constitute the principal sources. Where robust biomass estimates are unavailable, standardised catch-per-unit-effort data or validated distribution models could be employed as secondary proxies (Cheung et al., 2010; Palacios-Abrantes et al., 2025).

Historical Participation (HP) should measure the State’s mean proportion of verified catch or fishing effort for the stock over an agreed rolling reference period. A ten-year period may provide an illustrative baseline, drawing principally upon RFMO catch and effort databases, FAO statistics, verified national logbooks and observer data (FAO, n.d.; Gray, 2024).

Ecosystem Sustainability Performance (ESP), as defined in Section 4.1, focuses primarily on State-level performance. Candidate indicators include quota compliance, by-catch and discard compliance, reporting and data-submission performance, monitoring and enforcement implementation, and contributions to agreed scientific programmes. The purpose is to reward or recognise compliance-relevant performance within the allocation exercise without duplicating the scientific determination of the TAC. Indicator selection should be tailored to the legal powers and data systems of the relevant RFMO.

Climate Vulnerability (CV) should assess the vulnerability of the State’s fisheries sector to climate-driven ecological change through measures of exposure, sensitivity and adaptive capacity. Peer-reviewed fisheries vulnerability indices and verified national or international climate and fisheries assessments could be used for this purpose (Blasiak et al., 2017).

Food-Security and Developmental Dependence (FSD) should assess the extent to which the relevant fishery contributes to dietary protein, employment, coastal livelihoods, domestic value addition, government revenue and fisheries-related economic dependence, including access-fee revenue derived from foreign vessels fishing within a coastal State’s EEZ. Appropriate sources include FAO nutrition and fisheries-employment data, national accounts, government budget data and verified access-fee statistics. This dimension is separated from EAN because it seeks to quantify identifiable dependence directly rather than leave it to residual equitable discretion (Bell et al., 2021).

Finally, Equitable Allocation Need (EAN) should identify distributive disadvantages not already captured by CV or FSD, such as limited alternative fishing opportunities, genuine new-entrant disadvantages or disproportionate climate-related losses that remain after the other dimensions have been applied. To prevent EAN from becoming an unrestricted adjustment variable, the RFMO should agree eligible indicators, evidentiary thresholds and any cap on the EAN contribution before calculating allocations. This is necessarily a negotiated choice and may itself be difficult to agree under consensus-based decision-making.

Several methodological qualifications are necessary. Contemporary stock distribution should normally be based upon a multi-year moving average rather than a single-year observation. A three-year average may provide an illustrative starting point, reducing the risk that temporary environmental anomalies or short-term distributional changes trigger disproportionate reallocations. The three-year period should nevertheless be regarded as a design parameter rather than a universally optimal threshold and may require adjustment according to the biological characteristics of the stock.

Historical participation should be measured directly rather than inversely. States with greater verified historical harvesting participation may receive a higher HP score because this dimension protects continuity in established fishing activity and associated investments. HP should not, however, be described as capturing all ‘reliance interests’. In particular, coastal-State dependence on access fees paid by foreign vessels is conceptually different from flag-State catch history and should be measured under FSD, with any remaining disproportionate loss considered under EAN. Historical fishing history may be represented through a multi-year average, while the appropriate reference period should be agreed for the relevant fishery rather than treated as universal.

Similarly, the ecosystem sustainability dimension should avoid duplicating the role of stock status in determining the TAC. Biological stock condition is already central to conservation decisions under UNCLOS and the UNFSA and may reflect the combined conduct of several States. Reusing overall stock status as an allocation indicator risks both double counting and attributing collective ecological conditions to individual participants. State-level compliance and sustainability performance therefore provide more appropriate distributive indicators (UNCLOS, art 61; UNFSA, arts 5–6).

Finally, CAAI calculations should include explicit classifications of data quality. Missing information should not automatically generate a zero score, since this could systematically disadvantage data-poor States. Missing values should instead trigger an agreed regional proxy, a documented imputation procedure, or temporary exclusion of the relevant component combined with proportional rescaling of the remaining weights. The method adopted should be disclosed alongside the final calculation (OECD and European Commission JRC, 2008, pp. 24–25, 55–62).

4.2.3 Avoiding double counting and controlling discretion

A composite index of this kind necessarily creates a risk that related indicators may reward the same underlying disadvantage more than once. This is particularly relevant to climate vulnerability, food-security dependence and equitable allocation because SIDS and developing coastal States may score highly across all three dimensions. Composite-indicator methodology therefore requires attention to conceptual overlap and statistical correlation among indicators (OECD and European Commission JRC, 2008, pp. 25–26, 63–81).

The CAAI addresses this problem by assigning each component a distinct function. Climate vulnerability measures exposure, sensitivity and adaptive capacity in relation to climate-induced fisheries change. Food-security and developmental dependence measures the consequences that reduced access to a fishery would have for nutrition, employment and livelihoods. Equitable allocation need is residual and should capture only distributive disadvantages that have not already been incorporated into the CV or FSD scores.

Accordingly, an RFMO relying upon the EAN component should expressly identify the additional disadvantage being addressed and demonstrate that it has not already been incorporated into another component. This residuality requirement limits both double counting and the potentially open-ended discretion associated with appeals to equity.

The RFMO’s technical body should additionally conduct correlation and sensitivity checks before final allocations are adopted. Where two indicators are so strongly related that they effectively measure the same underlying phenomenon, the indicator specification or corresponding weights should be reconsidered and the resulting decision publicly explained (OECD and European Commission JRC, 2008, pp. 63–81, 117–131).

4.2.4 Decision-making, review and stabilisation procedure

The CAAI is intended to operate through existing RFMO institutions rather than requiring the creation of a new international organisation or, necessarily, amendment of constituent treaties. This is consistent with the central role assigned to regional and subregional fisheries management organisations and arrangements under the UNFSA (UNFSA, arts 8–13).

Implementation could proceed through seven stages.

First, the relevant RFMO scientific body would determine or recommend the TAC according to the applicable conservation framework. This biological determination would precede, and remain analytically separate from, the distributive allocation exercise (UNCLOS, art 61; UNFSA, arts 5–6).

Secondly, the RFMO members would determine eligible participants in accordance with the constitutive instrument and applicable rules. Data compilation and technical analysis should then be assigned to the Secretariat, scientific committee, technical body or external scientific provider only to the extent permitted by the relevant RFMO’s mandate. Because institutional competences vary considerably, CAFAF does not assume that every Secretariat can conduct science, make allocation recommendations or determine eligibility. Relevant datasets, reference periods, proxies and missing-data rules should be published before calculation.

Thirdly, before any technical body calculates draft scores, members would have to agree the CAAI architecture for that allocation cycle: the six dimensions to be used, operational indicators, normalisation rules, weights, aggregation method, treatment of missing data and any stabilisation constraints. This is a critical political step rather than a merely technical exercise. Only after those choices have been adopted should the competent Secretariat or technical body normalise the indicators and calculate draft CAAI scores and provisional allocation shares.

Fourthly, those calculations would be circulated to participating States for a defined review period. States should be entitled to challenge factual errors, data quality, indicator construction or incorrect application of the agreed methodology, but not simply to renegotiate an unfavourable result outside the established criteria.

Fifthly, the relevant scientific or technical committee would resolve technical objections and undertake sensitivity analysis. At a minimum, the analysis should examine whether reasonable alternative normalisation methods or weighting configurations materially alter participating States’ rankings or allocation shares. Where minor methodological changes generate substantial differences, that uncertainty should be reported to the Commission (OECD and European Commission JRC, 2008, pp. 117–131).

Sixthly, the Commission would adopt the final allocation through the decision-making procedures applicable within the relevant RFMO. Any material departure from the CAAI-generated provisional allocation should be accompanied by publicly recorded reasons. The purpose of the index is therefore to structure and discipline institutional discretion rather than eliminate it.

Seventhly, allocations should be reassessed periodically, for example on the three-to-five-year review cycle considered below, while scientific information concerning the underlying stock may be updated more frequently where necessary.

A stabilisation mechanism should accompany periodic adjustment. Climate-responsive allocation necessarily requires some redistribution over time, but excessive year-to-year change could undermine legitimate reliance interests and political acceptance of the framework. An RFMO could therefore establish an ex ante transition corridor limiting the permissible change in a State’s quota share between review cycles. A 15 per cent threshold may be used for illustrative testing of the model but should not be treated as a universally appropriate rule without empirical validation. Where the index indicates that greater redistribution is justified, the outstanding adjustment could be phased across successive review cycles, subject to exceptions where conservation necessity requires more rapid change. Stabilisation devices are not alien to fisheries allocation. The EU Common Fisheries Policy’s principle of ‘relative stability’ preserves stable percentage shares among Member States, while quota-swapping and related flexibility mechanisms can moderate operational disruption (European Parliament, 2026; Council of the European Union, 2026; Carpenter et al., 2019). CAFAF would use stabilisation for a different purpose—not to freeze historical shares, but to phase climate-responsive adjustment. Any illustrative annual cap, such as 15%, should therefore be treated as a calibration parameter to be tested and negotiated rather than as a legally derived threshold.

The Northeast Atlantic mackerel dispute illustrates the potential operation of this approach. As the geographical distribution of the stock increasingly extended into Icelandic and Faroese waters, contemporary distribution would progressively have strengthened their allocation scores, whereas the historical participation component would have preserved part of the reliance interests of established fishing States. Rather than requiring an immediate choice between historically entrenched allocations and abrupt redistribution, a stabilisation mechanism could have phased the transition over successive review periods (Østhagen et al., 2022).

4.2.5 Methodological status of the CAAI

The methodological status of the proposed CAAI should be defined carefully. It is operationalised but not empirically validated. The proposal goes beyond a purely conceptual framework because it specifies the relationship between its six components, provides operational definitions and potential data sources, establishes normalisation and weighting rules, addresses missing data and double counting, translates scores into provisional quota shares and identifies an institutional decision-making and review procedure. In this sense, the architecture is sufficiently specified to permit replication, retrospective testing and prospective application.

At the same time, the model does not claim that equal weighting, a ten-year historical reference period, a three-year distributional average or any illustrative stabilisation threshold represents an empirically optimal configuration applicable to all fisheries. Composite-index methodology demonstrates that weighting, indicator selection, normalisation and missing-data treatment involve methodological choices capable of materially affecting the resulting scores (OECD and European Commission JRC, 2008, pp. 13–31, 83–117).

These parameters would therefore require calibration at the level of the relevant stock and RFMO through retrospective simulation, sensitivity analysis and consultation with appropriate scientific and technical bodies. Before formal implementation, an RFMO should back-test the CAAI against historical allocation disputes, compare alternative weighting and indicator structures and publish the distributive consequences of those choices (OECD and European Commission JRC, 2008, pp. 117–131).

The CAAI should consequently be characterised neither as a purely conceptual set of principles nor as a statistically validated universal algorithm. It is more accurately understood as a legally grounded, operational and testable allocation architecture that translates the normative principles of CAFAF into transparent decision rules while preserving room for scientifically justified and institutionally accountable calibration at RFMO level.

4.3 Periodic adaptive review mechanism and benefits of the model

The application of CAFAF to the four case studies illustrates how the framework could structure allocation decisions without assuming that it would eliminate the political disagreements underlying them. Its function would vary according to the ecological and institutional characteristics of each fishery.

In the Northeast Atlantic mackerel dispute, CAFAF could balance stability and flexibility by combining contemporary stock distribution with historical participation and by establishing predetermined review periods and ecological triggers for reconsidering allocations. Historical participation would protect legitimate reliance interests, while persistent scientifically demonstrated changes in stock distribution could justify gradual adjustment. This would not resolve competing coastal-State claims but could reduce reliance on ad hoc bargaining by requiring States to agree ex ante on the evidence, criteria and procedures governing subsequent reviews. The case also underlines a central institutional limit: if the applicable process requires consensus, predetermined criteria do not compel agreement. They can clarify the basis of disagreement and discipline bargaining, but a State may still resist a distributive outcome it regards as unacceptable.

In Pacific tuna fisheries, climate vulnerability requires more than simply identifying States as SIDS. It should reflect their exposure to climate-driven stock redistribution, their economic and food-security dependence on tuna, and their capacity to adapt to resulting losses. Tuna fisheries are particularly important to Pacific SIDS because they support government revenue—including access fees paid by foreign fleets—employment, development and food security, while climate change is projected to redistribute tuna biomass away from some EEZs (Bell et al., 2021). The CAAI would therefore consider contemporary stock distribution alongside indicators such as dependence on access-fee revenue, fisheries-related employment, food security and projected losses of tuna biomass. This would prevent geographical redistribution from automatically producing an equivalent redistribution of economic benefits away from highly dependent States (Goodman et al., 2022). Although this dependence is especially visible in the Western and Central Pacific, the underlying principle is general: where a coastal State relies materially on access fees or other public revenue generated by a transboundary fishery, climate-driven loss of stock from its EEZ should be visible within FSD and, where necessary, EAN rather than treated solely as a question of flag-State historical catch.

In CCAMLR, CAFAF would perform a different function. Climate-driven changes in stock distribution would not automatically justify corresponding changes in fishing opportunities; allocation would remain constrained by precautionary management, stock condition and ecosystem considerations. Climate-sensitive scientific information could instead trigger periodic review of existing arrangements. CAFAF cannot remove the difficulties created by consensus decision-making, but predetermined review procedures could reduce the matters requiring renewed negotiation.

The Central Arctic Ocean illustrates the more complex problem of new entrants. As Serdy demonstrates, international fisheries law must reconcile the interests of established participants with claims by States seeking access to fisheries, while avoiding both the permanent entrenchment of historical fishing and uncontrolled expansion of fishing capacity (Serdy, 2016, chs 1–2). CAFAF would therefore not guarantee new entrants an allocation merely on grounds of fairness. Rather, participation would be considered alongside conservation requirements, historical participation, contemporary stock distribution and developmental dependence. In an emerging fishery such as the Central Arctic Ocean, agreeing on these principles before commercial fishing becomes established could reduce the risk that first participation subsequently becomes the dominant basis of entitlement.

Overall, these cases do not demonstrate that CAFAF would necessarily produce agreement or an objectively optimal allocation. They show instead how a common framework could structure different allocation disputes while allowing its criteria to be adapted to the ecological, economic and institutional characteristics of individual fisheries.

4.4 Conclusion

The Climate-Adaptive Fisheries Allocation Framework offers a structured pathway for addressing the distributive consequences of climate-driven changes in transboundary fish stocks. By combining contemporary stock distribution with historical participation, ecosystem sustainability, climate vulnerability, food-security and developmental dependence, and equitable allocation, CAFAF provides a principled basis for adapting allocation without treating either ecological change or historical reliance as determinative in isolation. Its operationalisation through the CAAI and periodic review mechanisms could permit greater responsiveness to changing ecological conditions while retaining a degree of stability for States and fishing communities that have developed legitimate reliance interests over time.

The framework should nevertheless not be understood as eliminating distributive conflict or guaranteeing particular economic outcomes. Changes in allocation may still create adjustment costs, especially where redistribution is substantial. The function of historical participation and the proposed stabilisation mechanisms is therefore to moderate abrupt disruption rather than to prevent economic dislocation altogether. Likewise, CAFAF is intended to structure and discipline RFMO decision-making, while its CAAI component makes agreed allocation criteria more transparent and reproducible rather than replace political negotiation or the legal authority of the relevant institution. Its value lies primarily in making the considerations underlying allocation more explicit, transparent and capable of periodic reassessment as ecological and socio-economic conditions change.

CAFAF therefore represents an institutional design proposal rather than a claim to a universally optimal allocation formula. Its implementation would require calibration to the biological characteristics of individual stocks, the legal mandates of particular RFMOs and the availability and quality of relevant data. Nevertheless, the framework demonstrates that greater climate responsiveness need not require abandonment of existing international fisheries law. It may instead be pursued by operationalising the flexibility already contained within that legal framework through more transparent, evidence-based and periodically reviewable allocation procedures.

5 Conclusion

This article has examined whether international fisheries law is capable of responding to climate-driven redistribution of transboundary fish stocks and, in particular, whether existing legal principles can support more adaptive approaches to the allocation of fishing opportunities. The analysis demonstrates that UNCLOS, the UNFSA, relevant FAO instruments and associated environmental and climate frameworks already contain significant normative foundations for adaptation, including cooperation, conservation, the precautionary approach, ecosystem considerations, scientific responsiveness and recognition of economic and developmental interests. The principal difficulty is therefore not an absolute absence of relevant legal principles. Rather, it lies in translating those principles into allocation practices capable of responding to ecological change while accommodating established interests and maintaining institutional cooperation.

The comparative analysis illustrates different dimensions of this challenge. The Northeast Atlantic mackerel dispute demonstrates how changing stock distribution can destabilise established allocation expectations when contemporary geographical presence and historical participation diverge. Pacific tuna governance highlights the additional distributive consequences that redistribution may create for climate-vulnerable and fisheries-dependent SIDS. CCAMLR demonstrates the potential value of ecosystem-oriented and precautionary governance while also illustrating how consensus-based procedures may constrain timely institutional adaptation. The Central Arctic Ocean Agreement, by contrast, provides an example of anticipatory governance in which scientific cooperation and precaution have been institutionalised before large-scale commercial fishing becomes established. The Agreement should not be understood simply as a moratorium approaching a predetermined expiry: its structure permits continuing precautionary governance while leaving open the possibility that future fisheries may require additional conservation, participation and allocation arrangements. Across the cases, ecosystem-based management is therefore best understood as one source of adaptive capacity rather than a prerequisite for adaptive allocation. Equally important are the institutional treatment of scientific advice, stock assessments, distribution data and procedures for reopening negotiated shares.

These cases also demonstrate that historical participation remains an important but context-dependent consideration rather than a universally controlling principle. Existing fisheries regimes vary considerably in the weight they assign to historical catch, zonal attachment, contemporary distribution, developmental needs and ecosystem considerations. Climate-driven redistribution does not therefore require the wholesale rejection of historical participation. It requires a more systematic mechanism through which historical reliance can be balanced against contemporary ecological distribution, sustainability, vulnerability, food-security dependence and other equitable considerations.

The principal contribution of this article is accordingly the proposed Climate-Adaptive Fisheries Allocation Framework and its operational component, the Climate-Adaptive Allocation Index. CAFAF, comprising substantive dimensions, a negotiated procedural cycle and the CAAI decision-support component, translates the normative flexibility identified within existing international fisheries law into a structured allocation architecture, while the CAAI specifies how six distinct considerations—contemporary stock distribution, historical participation, ecosystem sustainability performance, climate vulnerability, food-security and developmental dependence, and equitable allocation need—could be measured, normalised, weighted and translated into provisional allocation shares. The model further incorporates safeguards concerning data quality, double counting, sensitivity analysis, institutional review and stabilisation. It is therefore intended to make allocation decisions more transparent and responsive without presenting the resulting index as an automatic legal entitlement or a substitute for RFMO decision-making.

The proposal nevertheless has important limitations. The CAAI is operationalised but has not yet been empirically validated, and the illustrative weighting structure, reference periods and stabilisation parameters should not be treated as universally optimal. Application would require stock-specific calibration, retrospective simulation and sensitivity testing, together with assessment by the scientific and technical bodies of the relevant RFMO. Future research should therefore test the framework against historical allocation disputes and available fisheries datasets in order to assess how alternative indicator specifications and weighting arrangements affect distributive outcomes. The most important limitation is political: neither CAFAF nor the CAAI can displace the voting and consensus rules of the competent institution. Experience in allocation negotiations such as the IOTC TCAC confirms that agreeing criteria, baselines and weights may itself be the central distributive contest.

Subject to these limitations, the analysis suggests that climate-adaptive fisheries allocation does not necessarily require the creation of an entirely new body of international law. Existing legal principles provide substantial space for adaptation, but that space must be converted into institutional procedures capable of responding systematically to changing ecological conditions. Moving beyond predominant or inflexible reliance on historical allocation does not mean disregarding legitimate historical interests. It means placing those interests within a broader, transparent and periodically reviewable allocation structure. CAFAF offers one possible architecture for achieving that balance and, in doing so, provides a basis for further legal, institutional and empirical development of climate-resilient fisheries governance.

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Footnotes

Edited by: Yen-Chiang Chang, Dalian Maritime University, China

Reviewed by: Kamal Azmi, University of Wollongong, Australia

Siyuan Zhang, Nanchang University, China