8.1 Introduction

This is a self-reflective essay that aims to discuss the contributions of non-judicial actors,Footnote ¹ ranging from United Nations’ (UN) bodies to academic researchers in legal, natural and social sciences, as well as non-governmental organizations (NGOs) and human rights holders, to treaty interpretation as a matter of research design of an inter- and transdisciplinary project – the One Ocean Hub,Footnote ² which the author led. The reflection allows to shed light on the role of diverse actors and experts to co-develop a mutually supportive interpretation of international environmental law, the law of the sea and international human rights law that contributes to enhance, and potentially transform, the protection of the marine environment and of the human rights dependent on a healthy ocean.

As discussed in other chapters of this edited volume, ‘the law and practice in specific fields of international law has reached an unprecedented level of sophistication’,Footnote ³ and this in itself has been a barrier to connecting efforts to address the intertwined challenges of the protection of the marine environment and the protection of human rights.Footnote ⁴ The inter-linkages among these challenges have become increasingly clear in non-legal research, notably in marine and social sciences research,Footnote ⁵ as well as in the actions of researcher-activists working in solidarity with human rights holders.Footnote ⁶ As part of a broader effort of mapping out the current trends in the study of the process of interpretation in international law, this chapter therefore reflects on the increasing need to interpret in an evolutive and mutually supportive manner the rules of international environmental law, the law of the sea and international human rights law. Such evolutive and mutually supportive interpretation is based on new knowledge integrating local experiences of lack of sustainability and other injustices, interdisciplinary scientific evidence and Indigenous and local knowledge systems shedding light on the interdependence of diverse international treaty objectives. This appears necessary with a view to enhancing equity and effectiveness in the realization of the objectives of relevant treatiesFootnote ⁷ and potentially contribute to transforming current governance into more inclusive, sustainable and fair practices at different levels.

To that end, the chapter reflects on the efforts of different UN and other international bodies that provide advisory services to States on how to implement international law,Footnote ⁸ researcher-activists that seek to respond to pressing socio-cultural and environmental injustices at the local and national levels by relying on international law, as well as civil society and human rights holders working with them. The chapter focuses in particular on how these actors are increasingly working together to co-develop mutually supportive interpretations based on local-level experiences of lack of sustainability and of intergenerational injustices, interdisciplinary scientific evidence and Indigenous and local knowledge systems, in order to influence public authorities towards transforming environmental governance into more inclusive, sustainable and fair approaches. The chapter will take as a specific case study for analyzing this trend the One Ocean Hub research programme, which involved all the above-mentioned actors in activities related to the growing international recognition of human rights dependent on a healthy oceanFootnote ⁹ on the basis of mutually supportive interpretations of the international law on the marine environment, international biodiversity law, international climate change law and international human rights law. The chapter will first introduce the concepts of mutual supportiveness under the international law of treaty interpretation, together with the need for self-reflection by international law scholars and the role of collective approaches to interpretation as co-development. The One Ocean Hub will then be introduced as a case study of an inter- and transdisciplinary research programme that was designed on the basis of a mutually supportive interpretation, and the role of international law research as part of inter- and trans-disciplinarity. The chapter will then reflect on the distinctive role of a variety of non-judicial actors in co-developing mutually supportive interpretations of international law on the protection of the marine environment and human rights. Attention will focus on specific examples related to the recognition of ‘ocean defenders’ as environmental human rights defenders. The chapter will conclude with a reflection on how co-development of mutually supportive interpretations can also be institutionalized under treaty law, as a participatory monitoring, evaluation and learning approach embedded in treaty bodies devoted to the review of implementation and/or to technical and scientific advice.

8.2 Mutually Supportive Interpretations of International Law and the Need for Collective Approaches to Self-reflection

Mutual supportiveness is an emerging principle of international lawFootnote ¹⁰ that builds upon the customary rule of treaty interpretation of systemic integration, as enshrined in the Vienna Convention on the Law of Treaties – the need to take into account, ‘any relevant rules of international law applicable in the relationships between the parties’.Footnote ¹¹ Both mutual supportiveness and systemtic integration seek to find a reasonable way to apply different international instruments with minimal disturbance to the operation of the whole international legal system,Footnote ¹² with a view to preserving the unity of the international legal order.Footnote ¹³ In this sense, both also support the principle of good faith, which in its own right supports ‘cross-fertilization and coherence of international legal system’Footnote ¹⁴ through treaty interpretation.Footnote ¹⁵

Systemic integration, however, strictly speaking, applies only to treaties and other binding sources of international law, and there have been debates about whether it only applies to treaties among the same parties.Footnote ¹⁶ Due to these uncertainties, international law scholars have turned their attention to mutual supportiveness, which privileges an interpretative solution that also draws on decisions of treaty bodiesFootnote ¹⁷ and other forms of normative interactions among different international regimes.Footnote ¹⁸ Drawing on such multitude of international legal materials, mutual supportiveness requires, at the interpretative level, that states disqualify solutions to tensions between competing regimes involving the subordination of one regime to the other.Footnote ¹⁹ Mutual supportiveness is enshrined in specific multilateral environmental treatiesFootnote ²⁰ and is understood as a corollary of the principle sustainable development,Footnote ²¹ which is often part of the object and purpose of international environmental law treaties.Footnote ²²

In particular, mutual supportiveness contributes to clarify the legal content of fairness and equity, which are seen as a reflection of both sustainable development and of the general principle of good faith.Footnote ²³ Fairness is usually contained in open-ended treaty provisions in international environmental law and the law of the sea, so these provisions can be filled with content by establishing a linkage with different international legal sub-systems through mutual supportiveness.Footnote ²⁴ As I have argued in earlier work, in the specific case of human rights and the environment, these developments can be understood as evolutive interpretation of the object and purpose of relevant treaties (sustainable development, equity) in the light of emerging (natural and social) scientific evidence that human rights are dependent on healthy ecosystems.Footnote ²⁵ This interpretation in turn contributes to teleological clarity and effectivenessFootnote ²⁶ based on the realization that the respective objectives of different treaties are interdependent for their realizationFootnote ²⁷ and therefore increased cooperation is needed across these regimes to that end.Footnote ²⁸ Such interpretative directions have been adopted explicitly by a variety of global and regional human rights courtsFootnote ²⁹ and non-judicial bodiesFootnote ³⁰ in light of human rights and environmental treaties, such as the Convention on Biological Diversity (CBD), as well as in the light of decisions adopted under the CBD.Footnote ³¹

As I came to realize in my individual and collective international law research aimed at developing mutually supportive interpretations,Footnote ³² however, self-reflexivity needs to be a part of a heightened awareness with regard to unconscious and conscious power and influenceFootnote ³³ on international lawFootnote ³⁴ and national, ideological and structural biasesFootnote ³⁵ and blind spots.Footnote ³⁶ International law scholarship had already underscored that scholars do not explicitly interrogate whether their interpretative efforts are inclusive or exclusive of marginalized voices.Footnote ³⁷ As a result, I have been increasingly interested in the concept explored in the social sciences of self-reflexivity, which includes ‘the explicit articulation of values, assumptions and normative orientations; and renewed attention to asymmetries in power’Footnote ³⁸ in considering how we see our ‘scientific practice, our engagement with other agents within the process of research, how values are reflected in the work we do, and how we sense that research leads to social and political change and transformation’.Footnote ³⁹

In this reflection, I have developed a proposition that a self-reflective interpretative approach to mutual supportive interpretations requires a collective effort among legal scholarsFootnote ⁴⁰ to help one other to identify respective blind spots and biases.Footnote ⁴¹ Based on a distinction proposed by Neil Walker, I have argued that ‘pragmatist’, ‘idealist’ and ‘radically critical’ legal scholarsFootnote ⁴² should work together and constructively challenge one another with their respective insights on other scholars’ limitations. Critical legal scholars can support other lawyers with their ‘systematic attempt to include both the dimension of power and a theory of domination, and the relentless questioning of the “dark sides” of apparently emancipatory and progressive agendas’ in law.Footnote ⁴³ In turn, pragmatic lawyers can support critical lawyers in fully taking into account the actual nuances in the law and support idealist lawyers in anchoring their arguments in existing details of the law or actual workings of it. For their part, idealist lawyers can support both critical and pragmatic legal scholars to move beyond a negative critique or technicist analysis of the law, towards the development of a constructive proposition that can systematically consider the dark sides of law and accurately assess opportunities and constraints in its detailed workings.

What I explored more in my current collaborative research is the contribution of an even broader conversation with other epistemic communities, such as environmental justice scholarsFootnote ⁴⁴ and transdisciplinary researchers exploring the points of contact between different knowledge systems, including natural and social sciences, Indigenous and local knowledge systems and other forms of knowing. Such conversation can feed into the co-developing of mutually supportive interpretations of international law that respond to the needs, insights and life experiences of those most vulnerable to environmental degradation, while taking into account historic, systemic and cross-scalar injustices and carefully surfacing blind spots among all co-researchers, as discussed below.

8.3 The One Ocean Hub as an Example of Research Design Inspired by Mutually Supportive Interpretation

The One Ocean Hub (2019–25) was an inter- and transdisciplinary ocean research collaboration aiming to support fair and inclusive decision-making for a healthy ocean whereby people and the planet flourish. The Hub sought, from the outset, to integrate marine and social sciences, and the arts, as well as Indigenous and local knowledge systems and other forms of knowing, by relying on mutually supportive interpretations of international law on human rights and the marine environment. Such mutually supportive interpretation acted as a connecting frame across academic disciplines and diverse knowledge systems and as a platform for influencing ocean governance across temporal and geographical scales. The attention to different scales implies attention both to historical and current sources of injustices, including intergenerational trauma and colonial legacies, as well as to influences across different geographical scales, including local-to-global or global-to-local dynamics and Global North/South dynamics.

As an inter- and transdisciplinary ocean researchFootnote ⁴⁵ collaboration that was specifically mandated by its funder to achieve long-lasting, sustainable development impacts,Footnote ⁴⁶ the One Ocean Hub had the ambition to serve as a prototype for transformative ocean governance at different scales. Interdisciplinarity refers to efforts to integrate research efforts across different academic disciplines: the intention and challenge here is to move beyond multi-disciplinarity, where different academic disciplines proceed in parallel, and their separate findings are then brought together (juxtaposed) at the end. Instead, interdisciplinarity entails that the basic assumptions, key concepts and prior findings of various disciplines interrogate and challenge one another at the outset of the project, with a view to identifying respective blind spots and biases, eventually leading to the co-identification of research questions, which will then be pursued by various constellations of mixed approaches and findings from different disciplines. At that point, it is still possible and helpful to undertake also disciplinary research (including intra-disciplinary research, such as across different areas of legal scholarship) as long as the research questions are clearly anchored in and informed by the overall interdisciplinary research approach of the project and there are iterative ways to keep interrogating disciplinary research from the perspective of the other disciplines. In addition, transdisciplinarity refers to the effort to co-develop research across academic disciplines and diverse knowledge systems, such as Indigenous science and local knowledge, and the lived experiences and distinctive insights of other human rights holders, such as women and children.

The Hub brought together ocean-dependent people, decision-makers, and civil society in Ghana, Namibia and South Africa, and academic researchers from these countries, the UK and the two regional universities in the Caribbean and South Pacific. In addition, the Hub included legal officers from UN bodies: the UN Environment Programme, the UN Division on Ocean Affairs and the Law of the Sea, the UN Development Programme, the Food and Agriculture Organization of the UN and the Convention on Biological Diversity.Footnote ⁴⁷ Over time, the One Ocean Hub also worked closely with the Office of the High Commissioner for Human Rights and several UN Special Rapporteurs, particularly on Environment and Human Rights, Climate Change and the Right to Food. The Hub, therefore, was conceived as an ambitious attempt to co-develop knowledge across disciplines in different sectors and at different scales (global-local) to address multiple challenges to ocean health that undermine multiple Sustainable Development Goals (SDGs), while developing capacities and approaches to value, and learn from, different knowledge systems and voices at different scales. This was considered necessary to respond more holistically to the cumulative challenges facing marine ecosystems and undermining their multiple contributions to sustainable development.

The Hub research design, and model for research partnerships with all these diverse actors, was framed by international law scholarship and included explicit commitments to contribute to the mutually supportive and evolutive interpretation of international environmental law, the law of the sea and international human rights law in the light of co-produced knowledge on local experiences of lack of sustainability and injustices, interdisciplinary scientific evidence and Indigenous science and local knowledge systems. Specifically, the Hub aimed to develop a mutually supportive interpretation of the ecosystem-based approach under international environmental law and the human rights–based approaches for enhancing the effectiveness and fairness of the implementation of the law of the sea. This was with a view to supporting the implementation of the law of the sea to address multiple and cumulative threats: ocean plastics; ownership, tenure, stewardship and benefit-sharing of ocean space and resources; sustainable renewables and tourism development; climate change responses and disaster risk reduction. To that end, the One Ocean Hub was conceived as the first attempt to test the potential of the Framework Principles on Human Rights and the Environment developed by the UN Special Rapporteur on Human Rights and the Environment, John Knox,Footnote ⁴⁸ to guide the development of coherent, pro-poor, gender-sensitive, climate-proofed and transparent frameworks for ocean management across these sectors.

The Hub took as interdisciplinary research questions to what extent international law on the marine environment is a governance problem, why this is the case and who (among humans and across the marine environment) is most affected by it.Footnote ⁴⁹ Those interdisciplinary research questions were, in turn, meant to allow the Hub to test the extent to which international law can overcome its perceived limits to address intractable challenges through creative reading of existing legal instruments and legal forecasting,Footnote ⁵⁰ based on the understanding arising from the social and marine sciences research, as well as diverse knowledge systems. For instance, what is the potential of legal processes on public consultations, from the local to the international level, to truly take into account the lived experiences, needs, aspirations, distinct knowledge systems and human rights of Indigenous peoples and other ocean-dependent communities, as well as rural women and children, as they are developed and run in ways that are inherently limiting and disempowering.Footnote ⁵¹

The underlying intuition was that the way science and evidence are produced to support future decision-making on the ocean (but also other areas of the global and national sustainable development agendas) is where one needs to ensure genuine co-development by different knowledge holders. Without a co-developed integrated evidence base, it is much harder for ocean decision-makers to consider and understand the perspectives of those that are usually not represented in scientific knowledge production, and therefore to give due consideration to their insights on ocean health and human well-being. In other words, without the inclusion of human rights holders and diverse knowledge holders in the production of evidence base, the opportunities to protect their human rights in decision-making are drastically reduced. On the other hand, relying on the recognition in international law of the interdependence of a healthy environment (including a healthy ocean) and basic human needs (protected as human rights)Footnote ⁵² – as a matter of international law interpretation and research design – served to underscore the need for researchers to engage in inter- and transdisciplinary practices. In turn, integrated evidence from inter- and transdisciplinary research supports decision-makers to prioritize and take action on, as a matter of international law, key findings from the marine and social sciences that aligned in showing how to protect the marine environment with clear benefits for the protection of basic human needs. As part of this process, international law scholarship, particularly focused on treaty interpretation, contributed to build the capacity of different sectors of society (small-scale fishers, Indigenous Peoples, rural women, children, and researchers themselves) to demand legal protection for the ocean and their ocean-dependent human rights and to clarify the corresponding duties of public authorities.Footnote ⁵³

The ultimate assumption of the One Ocean Hub was that the interpretation of international law, in a dialogue with marine and social sciences research co-developed with diverse knowledge holders and human rights holders, could contribute to transformationFootnote ⁵⁴ – the shift away ‘from the technocratic and regulatory fix of environmental problems to more fundamental and transformative changes in social-political processes and economic relations’Footnote ⁵⁵ – in ocean governance at different scales.Footnote ⁵⁶ Here the overarching research question was how to interpret – to the full extent of their potential – provisions in international environmental law, the law of the sea and international human rights lawFootnote ⁵⁷ to identify ‘solutions that also have sustainable impacts at other scales and in other sectors’ and ‘empower those whose interests are currently not being met and represent transformative sustainability values’.Footnote ⁵⁸

To close the circle, transformation is understood to require transdisciplinary governance – the recognition of different knowledge systems and the inclusion of underrepresented types of knowledge in decision-making processes.Footnote ⁵⁹ International environmental law, to some extent, and international human rights law already recognize the need to recognize and integrate Indigenous and local knowledge,Footnote ⁶⁰ but much remains to be clarified about how to genuinely and respectfully do so, while preventing a shifting of the burden of response onto the vulnerable and addressing issues of power and legitimacy.Footnote ⁶¹ These were further research questions that shaped the design and practices of the One Ocean Hub and shed light on the topicality of interpretation across international environmental law, the law of the sea and international human rights law to support transdisciplinarity as an essential precondition for transformation. Transdisciplinarity, as mentioned above, requires engaging with and recognizing the value of non-academic experts, and from an interpretation perspective, this specifically requires engaging with understandings of the law and its underpinnings from legal professionals outside academia (such as UN officers, or lawyers working in NGOs) as well as with Indigenous peoples and local community representatives or children. These were the non-judicial actors that, together with legal scholars, contributed to the co-development of mutually supportive interpretations under the One Ocean Hub.

8.4 The Role of Non-judicial Actors

There is already a significant body of literature on the practices and importance of interpretation ‘from below’ in international human rights law,Footnote ⁶² in particular with a view to overcoming colonial legacies and preventing cultural impositions. These interpretative debates, however, remain limited in international environmental law and even more so in the law of the sea. It has thus been the area of cross-fertilization between international environmental law and international human rights law that initially created a space for shared scholarship on the importance of interpretation from below, notably with a focus on Indigenous Peoples’ human rights.Footnote ⁶³

On the one hand, these mutually supportive interpretation efforts serve to identify and address blind spots and limitations in the State-centric international environmental law, notably with regard to indeterminate environmental obligations with a very wide margin of discretion and an apparent lack of procedural guarantees.Footnote ⁶⁴ A paradigmatic example is that of obligations to carry out environmental impact assessments, which can be found in general international law,Footnote ⁶⁵ as well as international biodiversity lawFootnote ⁶⁶ and the law of the sea.Footnote ⁶⁷ These obligations have been considered so general by the International Court of Justice that the precise content and process of an environmental impact assessment (EIA) was considered a matter left to the State’s discretion.Footnote ⁶⁸ The ICJ, however, in reaching this conclusion, did not consider that the 196 CBD Parties had already clarified, by consensus, the content and process of an EIA to a significant degree.Footnote ⁶⁹ In addition, in a separate decision, the International Court of Justice (ICJ) had interpreted the wording of the applicable CBD provision on EIA as not even giving rise to a legally binding obligation, because of the vagueness of its formulation.Footnote ⁷⁰ Instead, in my previous legal research, I had contended that the CBD wordingFootnote ⁷¹ only opens up a margin of discretion for different parties to decide how (not whether) to implement such duty.Footnote ⁷² This margin of discretion is further limited by the joint reading of States’ obligations to prevent negative impacts on the marine environment under their jurisdiction, pursuant to the law of the seaFootnote ⁷³ and on human rights arising from biodiversity degradation under international biodiversity law and international human rights law.Footnote ⁷⁴ Hub research expanded this argument, by showing how diffuse environmental harm and degradation of nature’s benefits to human well-being (which could be considered foreseeable negative impacts on human rights), as well as historical evidence on marginalization from decision-making and current disregard for cultural rights linked to the effective protection of the marine environment, were routinely left out of EIAs.Footnote ⁷⁵ A mutually supportive interpretation of international biodiversity law, the law of the sea and international human rights law, therefore, served to identify some minimum content for the EIA obligation, which allowed to take into account the findings from the marine sciences about environmental blind spots in current EIA practices, as well as social sciences findings about negative impacts on human rights.Footnote ⁷⁶ This interpretation finds resonance in the 2023 Agreement on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction, which requires States to carry out EIAsFootnote ⁷⁷ in order to duly consider ‘consequences of climate change, ocean acidification and related impacts’,Footnote ⁷⁸ as well as ‘economic, social, cultural and human health impacts’.Footnote ⁷⁹ This is therefore an example in which mutually supportive interpretations contribute to the evolutive and effective interpretation of the law of the sea, by providing more normative detail to generic terms, with a view to better achieving interdependent treaty objectives in the light of new (natural and social) scientific evidence, local intergenerational experiences of lack of sustainability and injustices, and Indigenous Peoples’ and local knowledge systems.

Such a mutually supportive interpretation is innovative because while human rights and the environment has been a well-established area of international law scholarship since the 1990s,Footnote ⁸⁰ it has mainly focused on land-based issues and more recently on climate change.Footnote ⁸¹ Instead, little attention has been paid until very recently to human rights issues related to the protection of the marine environment, in particular of marine areas beyond national jurisdiction.Footnote ⁸² The case of the human rights dimensions of deep-seabed mining are quite instructive in this respect: international law scholarship started raising these questions only in 2019 from an Indigenous Peoples’ human rights perspective,Footnote ⁸³ and in 2022 from a general human rights perspective,Footnote ⁸⁴ with the UN Human Rights Office issuing a note in 2023.Footnote ⁸⁵ These interpretative developments can be explained on the basis of the emerging marine biodiversity evidence on the irreversible environmental impacts of deep-seabed miningFootnote ⁸⁶ and social science research and Indigenous knowledgeFootnote ⁸⁷ on the importance of the deep seabed for humankind.

As part of this ongoing process of cross-fertilization with these areas of international law, the One Ocean Hub researchers partnered with different UN bodies, whose mandates focused on human rights, the environment and the ocean, respectively. The partnership meant discussing research questions with UN officers to make sure that research findings could contribute to ongoing international negotiations or UN-led legal advisory and capacity-building initiatives to support the implementation of international law and guidelines at the national level. Interestingly, through these conversations, it also became clear which international law interpretation questions were identified but could not be investigated by UN officers themselves, either for lack of research time and resources, or for the risk of appearing to overstep their mandate. For instance, fully understanding the extent of the human rights–based approach to small-scale fisheries, particularly in as far as it related also to cultural rights and intangible ocean cultural heritage, required a new joint effort between Hub researchers, the Food and Agriculture Organization (FAO) and the Office of the High Commissioner for Human Rights (OHCHR), with the two UN bodies collaborating for the first time on that topic.Footnote ⁸⁸ In particular, social sciences and art-based participatory research in South Africa served to shed a light on the lack of understanding and consideration of intangible cultural and spiritual connection of certain Indigenous Peoples with the seabed. This in turn led to a disregard for their procedural rights in decision-making processes on offshore oil and gas exploration that would negatively impact also on their fishing activities and human right to food.Footnote ⁸⁹ These considerations, in addition, revealed the need to consider and protect the human rights of fishers also in the context of the conservation and management of marine areas beyond national jurisdiction, including from a climate change perspective.Footnote ⁹⁰ Conversely, it was difficult for FAO to integrate human rights considerations in its role as one of the relevant UN agencies involved in the development and implementation of the WTO Fisheries Subsidies Agreement.Footnote ⁹¹ So, an independent academic reflection on the need to interpret that Agreement and shape its implementation in accordance with the protection of human rights, including the human rights of small-scale fishers, was necessary. Such academic reflection allowed to carefully identify the role of FAO in supporting the human rights–based approach as part of its capacity-building mandate vis-à-vis States,Footnote ⁹² as opposed to a monitoring approach that would appear more appropriate for international human rights treaty bodies.

The collaboration between international law scholars and marine scientists under the One Ocean Hub was also distinctly instructive in supporting a mutually supportive interpretation between international biodiversity law, the law of the sea and international human rights law. Fisheries sciences experts were developing an evidence base of collapsing fisheries, and tools for the government to manage enhanced risks for the conservation and sustainable use of marine biodiversity due to other pressures, exacerbated by climate change. In addition, deep-sea biodiversity scientists clarified the current state of knowledge of the state and functioning of life in the depths of the marine environment, as well as the limitations of such knowledge that provide grounds for precautionary approach. Finally, ecosystem services research provided the essential bridging evidence between the knowledge of the functions of marine life and its complexes and benefits to human well-being (nutrition, health, cultural and spiritual well-being, purification of water and air, and resilience to climate change)Footnote ⁹³. In other words, ecosystem services research explained how and to what extent a healthy ocean contributes to the protection of a variety of human rights. At the same time, collaboration between international law scholars and marine scientists allowed to identify blind spots in the production of natural science evidence in terms of assumptions about undifferentiated human needs and vulnerabilities, as well as the limited capacity to integrate cultural rights or diverse knowledge systems within current methods for assessing, mapping and modelling impacts and responses for the protection of the marine environment.Footnote ⁹⁴

Marine science experts were quite familiar with international environmental law concepts related to precaution and the ecosystem approach but were generally unaware of the connections between these concepts and international human rights law.Footnote ⁹⁵ In effect, the interpretative efforts of the 196 Parties to the CBD had already clarified that the ecosystem approach entails understanding and factoring in societal choices, rights and interests of Indigenous Peoples and local communities, along with intrinsic as well as tangible and intangible values attached to biodiversity, ultimately leading to a balance between local interests and the wider public interest. It also entails ensuring appropriate representation of community interests in the decision-making process.Footnote ⁹⁶ Instead, marine scientists generally saw their role as carrying out technical stakeholder consultations for the purposes of gaining social traction of their findings, while for their part they felt an obligation to treat all groups (be they large-scale business as opposed to subsistence fishers) equally despite power imbalances and differentiated vulnerabilities to environmental impacts. As a result, their evidence base and tools for decision-making would not support decision-makers to fulfil their international human rights obligations in the context of the protection of the marine environment. This is because such evidence did not include disaggregated data analysis, consideration of differentiated impacts on different sectors of society and an effort to prioritize the needs of the most vulnerable as part of ensuring environmental sustainability of ocean use or marine conservation.

The collaboration between international law scholars and social scientists, notably experts in educational sociology, ethnographic sociology, anthropology, human geography, history and political ecology, as well as art-based participatory research approaches, was crucial to understand lived experiences, living memories, the existence of distinctive knowledge systemsFootnote ⁹⁷ and the differentiated impacts of the degradation of ocean health and the modalities and impacts of exclusionary ocean research and governance practices on human rights holders. In other words, it allowed all researchers to realize where their own assumptions and the scope of their work had prevented consideration of relevant human rights and how to ensure the protection of persons against negative consequences of their scientific research or its applications on the environment.Footnote ⁹⁸ Further, earlier social sciences research on ocean-dependent communities, small-scale fisheries, environmental justice issues and exclusion in decision-making also revealed itself essential to ground the design and planning of transdisciplimary research, with a view to ensuring contextualization and avoiding ‘parachute science’.Footnote ⁹⁹ It also served to build or enhance the understanding and capacity of other researchers, from law and the marine sciences, to relate their own work to the local context and identify potential areas of interdisciplinary collaboration across the team. This allowed researchers to ensure that priorities for scientific research should focus on key issues for the most vulnerable and strive towards scientific progress that is critical to the enjoyment of the human right to health and other economic, social and cultural rights.Footnote ¹⁰⁰ These approaches were then essential to engage in a respectful way and ensure mutual learning and knowledge co-development with human rights holders themselves, without creating new exclusion or injustices in the context of other research under the One Ocean Hub.Footnote ¹⁰¹

In particular, environmental justice scholarship from the Global SouthFootnote ¹⁰² provides a plural and contextually located approach to contrast Western ways of thinking and doing,Footnote ¹⁰³ which are underlined by a perception that humans and other species of plants and animals are distinct and separate, on a universal scale.Footnote ¹⁰⁴ This area of scholarship unveils how today’s environmental injustices are profoundly shaped by persistent colonial legaciesFootnote ¹⁰⁵ and intertwined global and local power imbalances arising from competing economic interests, exploitative processes and inequality, which are increasing embodied in growing demand for marine resources, globally and nationally.Footnote ¹⁰⁶ Environmental justice scholarship from the Global South also critically reflects on how ‘these dominant frameworks frequently draw on science as the only legitimate form of knowledge for understanding our natural environments and developing related policies and regulations. This can inadvertently delegitimize and exclude other ways of knowing and living with the natural world, such as Indigenous science and local knowledge.’Footnote ¹⁰⁷ The dialogue with environmental justice scholars from the Global South, including their praxis as researchers and human rights advocates working in solidarity with human rights holders, supported imaginative thinking on alleviating planetary harms and socio-cultural and economic injusticesFootnote ¹⁰⁸ and fed into interpretative efforts at the intersection of international environmental law, international human rights law and the law of the sea.

In particular, social sciences and art-based participatory research in South Africa served to shed a light on the lack of understanding and consideration of intangible cultural and spiritual connection of certain Indigenous peoples with the seabed. This in turn led to a disregard for their procedural rights in decision-making processes on offshore oil and gas exploration that would negatively impact also on their fishing activities and human right to food. These approaches place the experiences, needs, knowledge and human rights of local actors at the outset as a way to interrogate different meanings of international law, to identify how to best respond to local understandings of sustainability and justice, as well as be aligned with the natural sciences evidence and, on that basis, assess whether national law was in compliance with the underlying international treaties.Footnote ¹⁰⁹

Over time, this approach allowed the Hub to contribute to the development of new international interpretative guidance on the human rights of the child and a healthy environment,Footnote ¹¹⁰ as well as integrate such interpretation in ongoing research efforts.Footnote ¹¹¹ Hub interdisciplinary research on the importance of marine biodiversity for children’s human rights, including their right to development and culture,Footnote ¹¹² as well as on the importance of a healthy ocean for climate change mitigation and adaptationFootnote ¹¹³ and insights arising from partnerships with children rights organizations at the ocean-climate nexus,Footnote ¹¹⁴ were shared in various ways during the development of the 2023 UN General Comment on Children’s Human Rights and the Environment, with a focus on Climate Change.Footnote ¹¹⁵ As a result, the General Comment clarifies that children’s human right to a healthy environment includes obligations for States to take ‘immediate action’ to ‘conserve, protect and restore biodiversity’, ’prevent marine pollution, by banning the direct or indirect introduction of substances into the marine environment that are hazardous to children’s health and marine ecosystems’ and ‘ transform industrial fisheries to produce healthy and sustainable food aimed at preventing malnutrition and promoting children’s growth and development’.Footnote ¹¹⁶ This guidance, therefore, enshrines a mutually supportive and evolutive interpretation of international human rights law, international biodiversity law, international climate change law and the law of the sea,Footnote ¹¹⁷ on the basis of new (natural and social) scientific evidence of the interdependence of their respective objectives as reflected in children’s own understandings. Such a holistic interpretation of children’s human right to a healthy environment has then supported further interpretative work by the One Ocean Hub, as part of international civil society networks advocating for the respect of children’s human rights in the international climate change regime. This co-development led to the integration of interpretative arguments prioritizing ocean-based and other nature-based solutions to climate change,Footnote ¹¹⁸ as opposed to unproven and dangerous technologies to mitigate climate change.Footnote ¹¹⁹ These contributions were in addition to interpretative arguments focused on enhanced social protection for children in the face of the negative impacts of climate change. These are further examples of mutually supportive interpretations based on international biodiversity law and international human rights law that underpin an evolutive interpretation of international law of the sea and international climate change law based on a new understanding of the interdependence of their respective objectives in the light of local experiences of lack of sustainability and injustices, interdisciplinary scientific evidence and Indigenous science and local knowledge systems.

8.5 Aligning Interpretative Efforts: The Case of Ocean Defenders

This section now delves into a particular area of co-development of a mutually supportive interpretation that emerged from the interactions among the non-judicial actors involved in the One Ocean Hub: the concept of ‘ocean defenders’ as part of environmental human rights defenders. Environmental human rights defenders were defined by former UN Special Rapporteur on Human Rights Defenders Michel Forst, as the individuals and communities that raise awareness about the negative impacts on human rights of unsustainable decisions on the environment.Footnote ¹²⁰ Environmental human rights defenders are increasingly the object of (often lethal) attacks by governments or private actors, as well as harassment, denigration or side-lining.Footnote ¹²¹ They are recognized and studied as agents of change,Footnote ¹²² including for their role in preventing unsustainable and unjust uses of the environment that may lead to conflict.Footnote ¹²³

Environmental human rights defenders are entitled to all the rights and protections set out in the 1998 UN Declaration on the Right and Responsibility of Individuals, Groups and Organs of Society to Promote and Protect Universally Recognized Human Rights and Fundamental Freedoms (Declaration on Human Rights Defenders).Footnote ¹²⁴ To respect defenders’ human rights, States must ensure a safe and enabling environment for them to operate free from threats, harassment, intimidation and violence, including by providing appropriate training for security officials. Protection further entails publicly recognizing the contributions of defenders to society and ensuring that their work is not stigmatized.Footnote ¹²⁵ Heightened levels of protection are needed for child defenders.Footnote ¹²⁶

As for other areas of cross-fertilization between international human rights law and international environmental law, however, international interpretative guidance on environmental human rights defenders has mainly focused on land-based issues, and in fact there are often references to ‘land and environment human rights defenders’.Footnote ¹²⁷ As a result, the specific challenges faced by ocean defendersFootnote ¹²⁸ have not yet been specifically included in these interpretative efforts, which have very practical implications in terms of ensuring the prompt release of financial, legal and security support from UN country offices to defenders at risk. Nevertheless, One Ocean Hub researchers from an international law and social sciences background have contributed to UN consultations on this issueFootnote ¹²⁹ and are collaborating with researchers and activists around the world to increase the documentation and understanding of the work and risks of ocean defenders.Footnote ¹³⁰ They are also raising awareness among conservation organizations and marine scientistsFootnote ¹³¹ about the significance of scientific evidence on environmental vulnerabilities and specific needs for environmental protection with demands for environmental protection of ocean defenders. These demands are based on their interconnected human rights to livelihoods, health and culture, and to a healthy ocean. In other words, innovative solidarity practices emerged in connecting different bodies of evidence (from within and outside academia), whereby natural science evidence aligned with ocean defenders’ priorities in terms of environmental protection, and therefore also backing the protection of ocean-dependent human rights. In this case too, mutually supportive interpretations based on international biodiversity law and international law of the sea underpin an evolutive interpretation of international human rights law based on a novel understanding of the interdependence of their respective objects and purposes.

These inter- and transdisciplinary bases for mutually supportive interpretation have also been brought together into submissions to the three international tribunals requested to issue an advisory opinion on States’ climate change obligations – the International Tribunal for the Law of the Sea,Footnote ¹³² the ICJFootnote ¹³³ and the Inter-American Court of Human Rights.Footnote ¹³⁴ In all these submissions, mutually supportive interpretations drawing on the Hub’s inter- and transdisciplinary research emphasized the need to understand States’ obligations under the international climate change regime also in the light of the law of the sea, international biodiversity law and international human rights law, because of what biodiversity science shows about the role of the ocean in the global climate regulation, which is still overlookedFootnote ¹³⁵ under the international climate change regimeFootnote ¹³⁶ and the social science evidence and views of ocean defenders, including child and young ocean defenders.Footnote ¹³⁷ These submissions then included new interpretative arguments that State obligations across the treaties related to climate change, the sea, biodiversity and human rights imply a due diligence obligation to ensure the meaningful participation of ocean defenders in the design, implementation, financing, monitoring and review of climate, biodiversity and ocean policies, plans and actions, including ‘just transition’ or ‘blue economy’ policies, plans and actions, as well as marine protected areas and other marine conversation measures.Footnote ¹³⁸ This was accompanied by another interpretative argument about the need for States, as part of their human rights obligations related to climate change, to protect ocean defenders that protest against deep-seabed mining.Footnote ¹³⁹ The latter argument found support in statements made by the UN Special Rapporteur on Toxics and Human Rights and the Aarhus Convention Special Rapporteur on Defenders in March 2024 to the States members of the International Seabed Authority.Footnote ¹⁴⁰

8.6 Institutionalizing Treaty Interpretation Co-development under Existing Treaty Structures

There are opportunities as part of the implementation of treaties to advance these interpretations and in fact embed similar processes of interpretation co-development with ocean defenders as well as a range of diverse experts and knowledge holders, by re-imagining the composition and approaches of treaty-based implementation review bodies and/or technical and scientific advice committees.

Participatory governance and iterative learning from treaty implementation have already been considered in the literature on international environmental law as essential pre-conditions to ensure the effectiveness of certain treaty regimes because of the complexity of the subject matter and the need to understand different experiences of equity, as well as potential impacts across the biodiversity research, innovation and governance landscape.Footnote ¹⁴¹ Such an approach would be a departure from current practices focusing only on technical expertise and natural sciences background in subsidiary treaty bodies. Instead, the membership of these bodies could include experts from different communities of practices in the Global North and the Global South (scientists from different geographies and disciplines), notably with social scientists, Indigenous Peoples and local knowledge holders.Footnote ¹⁴² The role of social sciences experts would be essential to support the overcoming of stereotypes about the relevance and capacity of diverse knowledge holders to meaningfully contribute to international processes.Footnote ¹⁴³

This is also true for the genuine inclusion of children’s voices in these processes,Footnote ¹⁴⁴ which is something to which the whole UN Systems is committed to.Footnote ¹⁴⁵ Along similar lines, UN General Comment No 26 also clarified that

Methodologies developed by children’s rights experts could be adapted to international treaty bodies,Footnote ¹⁴⁷ with the benefit that these methodologies could also support transformative legal interpretation among adults,Footnote ¹⁴⁸ as they rely on fun, play and artsFootnote ¹⁴⁹ to challenge vested interests, power asymmetries and tendencies towards short-term decision-making.Footnote ¹⁵⁰

Thus re-conceived, these treaty-based review and advisory processes could support iterative interpretations of treaties in the light of changing scientific practices, scientific understandings of the status of the marine environment and the flow of its benefits to humankind, as well as evolving understanding of environmental sustainability and equity in the life experiences of ocean defenders. These treaty bodies could therefore integrate the insights from inter- and transdisciplinary dialogue into co-developed iterative interpretations of a treaty, which in turn would shape funding modalities, taking into account the range of needs of relevant human rights holders and setting research priorities to further support collaboration with diverse knowledge holders at national and local levels. They could also generally look at questions of efficacy together with questions of equity, with a view to suggesting clarifications in interpretation for the consideration by the governing body of the treaty. Given the need for systemic interpretation and joined-up implementation of treaties in the areas of climate change, biodiversity, the ocean and human rights, these subsidiary bodies could also maximize opportunities for regime interaction and cross-regime learning.Footnote ¹⁵¹

8.7 Conclusions

The triple planetary crisis (climate change, biodiversity loss and toxic pollution) and its multiple impacts on human well-being increasingly require evolutive and systemicFootnote ¹⁵² interpretation of State obligations across international environmental law, the law of the sea and international human rights law. Collective interpretative practices by non-judicial actors can support an understanding of how international law can effectively respond to these challenges, on the basis of the lived experiences of the most vulnerable human rights holders, across scales. This chapter calls attention towards inter- and transdisciplinary research projects as potentially fertile and flexible spaces for UN and other international bodies that provide advisory services to States on how to implement international law to co-identify critical legal questions and co-develop evolutive interpretative solutions with researchers in law, natural and social sciences and the arts, based on local-level experiences of lack of sustainability and injustices, interdisciplinary scientific evidence, Indigenous science and other knowledge systems.

These interpretative efforts can support national public authorities in ensuring the effectiveness of their treatiesFootnote ¹⁵³ and in shifting towards the transformation of environmental governance into more inclusive, sustainable and fair approaches that also contribute to the protection of human rights. Equally, they can support multilateral cooperation, and possibly be institutionalized under treaty law, as part of treaty bodies focusing on implementation review and on technical and scientific advice.

The importance of these interpretative collaboration efforts cannot be overestimated, as a form of transdisciplinary governance that can lead to the transformation needed to effectively tackle the triple planetary crisis – a systemic change across sectors and scales that ‘empower those whose interests are currently not being met and represent transformative sustainability values’,Footnote ¹⁵⁴ such as ocean defenders.