Integrated ocean governance is needed in the Southwest Atlantic Ocean to foster fisheries, conservation and resilience to climate change

Abstract

The Southwest Atlantic Ocean (SWAO) is a globally important region, where diverse water masses converge and mix, regulating the Earth’s climate while supporting productive fisheries and high marine biodiversity. Ecological connectivity is also substantial, with multiple species and ecosystems shared across multiple jurisdictions and international borders. However, despite historical efforts and more recent calls for regional management, the SWAO is one of the few large oceanic regions with no dedicated ocean governance body covering all shared resources. This disconnect is particularly alarming in the face of climate change, which is altering the distribution and abundance of fish stocks, shifting species ranges poleward, and intensifying uncertainty in marine resource management. A collaborative regional framework, rooted in ecosystem-based management, is urgently needed to foster sustainable management as well as bolster resilience to the impacts of climate change. As Brazil hosts a series of United Nations meetings on environmental topics, the region faces a decisive moment: either to remain reactive to external governance structures or to proactively design frameworks that reflect regional priorities, balance sovereignty concerns, and better integrate scientific evidence into decision-making. Thus, we invite decision makers, managers and scientists to take advantage of the political momentum in Latin America to advance integrated and multi-scale ocean governance, while strengthening ocean science diplomacy in the SWAO. This is a call to help navigate an uncertain future by addressing shared challenges and prioritizing ocean sustainability in the SWAO.

The Southwest Atlantic Ocean: a region of ecological and socio-economic importance

Extending over 17.65 million km² between 5°N and 60°S, the Southwest Atlantic Ocean (SWAO) encompasses diverse oceanic, biogeographic, and ecological features, which sustain exceptional biodiversity and fisheries of high socio-economic value (Fig. 1). Spread across and beyond national jurisdictions, the region harbors biodiversity hotspots, migratory corridors, and critical habitats that sustain spawning, mating, nursery, and feeding functions for multiple important and vulnerable species, including fish, sharks, cephalopods, and marine mammals such as southern and humpback whales, and orcas [1–3]. These result from geomorphological, hydrographic, and biogeochemical features that circumscribe distinct biogeographic provinces and ecoregions, supporting high levels of endemism and ecological cohesion [4, 5].

Fig. 1.

The Southwest Atlantic Ocean. Bathymetry shows shallow regions in yellow to deeper regions in purple. The black box represents The Food and Agriculture Organization’s Major Fishing Area 41. White lines represent the Exclusive Economic Zones of Brazil (mainland), Uruguay and Argentina (including the Islas Malvinas/Falkland Islands). Blue contour lines represent the different ecoregions considered here while the red ones represent ecoregions beyond SWAO, according to Spalding et al. 2007 [4]. Black dashed lines represent major currents. NBC, North Brazil Current. SEC, South Equatorial Current. BC, Brazil Current. MC, Malvinas Current, ACC, Antarctic Circumpolar Current, SAC, South Atlantic Current, ZG, Zapiola Gyre

The ecological significance of the SWAO also extends to fisheries (Fig. 2). Designated by the Food and Agriculture Organization of the United Nations (FAO) as Major Fishing Area 41 (Fig. 1), the SWAO has over 32,000 artisanal and industrial vessels, employing 896,000 people. In 2021, catches in these multispecies fisheries were estimated at 2 million tonnes, valued at $5 billion dollars [6]. Specifically, in northern Brazil (north of 20°S), the continental shelf supports small-scale multispecies fisheries, though often under limited statistical reporting coverage. Further south, industrial fisheries have developed along the Brazilian, Uruguayan, and Argentine shelves, targeting shared stocks of high commercial value [7–9]. Additionally, in the SWAO, connectivity between regions is strong. For example, in winter, fish, shrimp and squid stocks move northward from the northern Patagonian and Uruguayan shelves, to the southern Brazilian shelf where they represent a substantial component of the fishing industry in this productive and economically important region of Brazil [10, 11]. This connectivity results in a high number of shared stocks (transboundary, straddling, and straddling highly migratory, Box 1) in the catch composition of these countries (Fig. 2b) [12–14].

Box 1.

Glossary of terminology included in the present paper

Terminology	Definition
Atlantic meridional overturning circulation (AMOC)	A large system of ocean currents in the Atlantic Ocean that transports warm, salty surface waters northward and returns colder, deeper waters southward. It plays a critical role in regulating global climate by redistributing heat, influencing weather patterns, and affecting the carbon cycle and sea level
Ecosystem-based management (EBM)	A management that considers the whole social-ecological system (i.e., including human activities, social, and economic factors) to maintain ecological integrity and human well-being
High emission climate change scenario (SSP5-8.5)	Climate change scenario represents a future with high radiative forcing due to increased greenhouse gas emissions, leading to substantial global warming
Illegal, Unreported and Unregulated Fishing (IUU)	Fishing activities that violate national, regional, or international laws or occur outside the reach of such laws, undermining the sustainability of marine ecosystems
Ocean governance	The collective framework of policies, institutions, processes, and practices through which societies manage the use, conservation, and sustainable development of oceans and their resources
Ocean science diplomacy	An umbrella term to classify the phenomena that results from the multiple interactions of science with international relations, including the provision of scientific advice to ocean affairs, scientific cooperation driving foreign policy and diplomacy supporting science to address humanitarian challenges
Regional Fisheries Management Organization (RFMO)	International bodies where countries collaborate to manage and conserve valuable fish stocks that cross national boundaries such as transboundary, straddling and highly migratory stocks
Straddling highly migratory	Fish stocks (e.g., pelagic) that are widely distributed among international waters and non-adjacent exclusive economic zones
Straddling stocks	Fish stocks that cross the boundary of neighbouring exclusive economic zones and the high seas
Transboundary stocks	Fish stocks that occur throughout their life cycle, or in part, between two or more neighbouring exclusive economic zones

Fig. 2.

Species richness and catches in the Southwest Atlantic Ocean. a Species richness across all taxa (data from AquaMaps/AquaX, [15]). Black and white polygons represent the marine protected areas in the region (data from United Nations-World Conservation Monitoring Centre [16] and Instituto Chico Mendes de Conservação da Biodiversidade [17]). b Catch in each country’s EEZ from all stocks and shared stocks (data from The Sea Around Us, www.searoundus.com according to [18])

The ecological importance and rich fisheries productivity of the SWAO is underpinned by unique and complex oceanographic conditions (Fig. 1). Under the influence of relatively strong western boundary currents, namely, the North Brazil Current (NBC), Brazil Current (BC), and Malvinas Current (MC) (Fig. 1), the region is characterized by intense mixing between subtropical and subantarctic waters [19, 20]. In combination with frontal zones, eddies, upwelling, and major river basin discharges, these processes are responsible for highly productive ecosystems [21–24]. The strong spatial and temporal variability in the region shapes the distribution and abundance of marine communities, ultimately setting the SWAO among the most productive marine regions worldwide [6, 8, 25, 26].

Ocean governance in the SWAO

Brazil, Uruguay and Argentina are signatories of several United Nations (UN) conventions and treaties related to ocean governance and have extensively collaborated in implementing these provisions regionally. For example, they are all signatories of The United Nations Convention on the Law of the Sea (UNCLOS), the Convention on Biological Diversity (CBD), and The Agreement for the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction (BBNJ Agreement), which Brazil and Uruguay have ratified. Regionally, they maintain a strong record of cooperation within the framework of the International Commission for the Conservation of Atlantic Tunas (ICCAT), particularly through joint analyses and coordinated contributions to stock assessments (e.g., [27, 28]). Moreover, they are all signatories of the Zone of Peace and Cooperation of the South Atlantic (ZOPACAS, https://www.abc.gov.br/zopacas/default_en.aspx), a political alignment aimed to promote peace, security, and regional solidarity among South Atlantic coastal nations in Africa and South America.

However, integrated efforts in conservation and fisheries governance remain limited, as exemplified by the Port State Measures Agreement (PSMA). The PSMA is a bonding agreement and key instrument under the Code of Conduct for Responsible Fisheries. It requires Parties to strengthen oversight of foreign fishing vessels in order to combat illegal, unreported and unregulated (IUU) fishing by distant-water fleets. Its objective is to reduce the incentive of vessels engaged in IUU to continue to operate by preventing them from landing their catches in PSMA Parties’ ports, while also protecting national and international markets [29]. Nevertheless, at present, Uruguay is the only Party in the SWAO that has ratified the PSMA. Perhaps the best example of trilateral cooperation was the Comisión Asesora Regional de Pesca para el Atlántico Sudoccidental (CARPAS), established by FAO in 1962 [8]. CARPAS played an important role as the Regional Advisory Fisheries Commission for the Southwest Atlantic, coordinating fishery statistics, promoting biological research, and conducting stock assessments. However, CARPAS was officially abolished by FAO Conference Resolution 13/97 in 1997, following the creation of EEZs and the 1976 establishment of the Comisión Técnica Mixta del Frente Marítimo (CTMFM). The CTMFM assesses the status of fishery resources and proposes management measures within the Zona Común de Pesca Argentino-Uruguaya (ZCPAU). Today, the ZCPAU operates as a shared sovereignty area for the transboundary fisheries resources of Argentina and Uruguay. The CTMFM is recognized by FAO as the only regional fisheries body in the Southwest Atlantic. While strong bilateral arrangements exist between Argentina and Uruguay, Brazil’s engagement has remained comparatively incipient since the end of CARPAS, with most efforts being driven by classic scientific cooperation across a range of marine research topics [2, 7, 8].

Challenges abound in the SWAO

Well-documented geopolitical tensions in the SWAO continue to shape the region’s approaches to ocean governance and the sustainable management of marine resources, with these dynamics increasingly compounded by the dual pressures of IUU fishing and climate change. Conservation initiatives also remain limited, fragmented and frequently disconnected from fisheries management, undermining the capacity to safeguard ecosystem services and to respond effectively to cumulative pressures, including overfishing, habitat degradation, and climate-driven variability.

Governance challenges

Fisheries in the SWAO illustrate the tensions between governance, economic competition, and sustainability. The growing presence of distant water fleets with state-of-the-art exploitation technologies, particularly from Asia and Europe, targeting highly valuable resources such as squid and tuna, fosters unequal competition with both industrial and small-scale domestic fleets [30, 31]. This imbalance is further intensified by external subsidies and the use of flags of convenience, creating market asymmetries and pressures on the food security of local communities [32]. In parallel, these dynamics reflect the expansion of unregulated fisheries, such as for squid, that exploit institutional gaps in high-seas areas and at the margins of national jurisdictions [33]. This challenge is compounded by the absence of Brazil and Argentina from the PSMA. The geographic proximity between Uruguay, Brazil, and Argentina undermines the effectiveness of this Agreement, which relies in part on the difficulty of reaching ports outside the PSMA framework. When PSMA members border non-member States, foreign vessels can divert to non-PSMA ports or opportunistically reflag to domestic registries, a practice known as “flag domestication” [32]. Between 2016 and 2021, the number of port visits by vessels that reflagged to a domestic flag in Brazil and Uruguay have increased by around 27% and 57%, respectively [32]. While ratification of the PSMA represents an important step toward addressing IUU fishing in the region, its effectiveness ultimately depends on implementation, coordination, and complementary national measures. In this context, Brazil’s role as a signatory (but not a ratifying party) and Argentina’s existing port controls and non-signatory status highlights both the opportunities and the limitations of relying on PSMA alone.

The sovereignty dispute between Argentina and the United Kingdom over the Islas Malvinas/Falkland Islands, South Georgia, the South Sandwich Islands, and the surrounding maritime areas, intensified by the potential exploitation of shared marine resources, remains a central geopolitical challenge. Here, more than 42 coastal Small Scale Fisheries (SSF) are distributed along the Patagonian coast of Argentina [34], with management for most conducted independently and little progress towards joint research or coordinated and inclusive management agreements [35]. Against this backdrop, diplomacy from Brazil, Uruguay, and Argentina have resisted the establishment of a Regional Fisheries Management Organization (RFMO) for the SWAO. Such resistance stems not only from the longstanding historical disputes but also from concerns that multilateral regulation could provide a legal foothold for extra-regional actors, thereby diluting national sovereignty and undermining regional autonomy over strategic fish stocks [8]. Lessons for the region can be drawn from other contexts, such as the Pacific Island States, which feared that the establishment of the Western and Central Pacific Fisheries Commission (WCPFC) could serve as a legal foothold for extra-regional actors to dilute coastal state sovereignty. These concerns led to the development of strategies to resist the inclusion of distant-water fishing nations in fisheries management, once the UN Fish Stocks Agreement (UNFSA) was stablished, providing international legal legitimacy for their position [36]. Additionally, south of 45°S, valuable transboundary stocks are exploited by fleets of multiple nationalities. For example, the crab fishery (joint harvest of the Southern king crab Lithodes santolla and the stone crab Paralomis granulosa) in the Beagle Channel is shared between Argentina and Chile, but managed independently [35]. Governance in this region is fragmented and often unilateral, with scientific evidence not fully integrated into decision-making. Past collaboration through the South Atlantic Fisheries Commission delivered some joint measures, but it has been suspended since 2020. More recently, bilateral research initiatives, such as those between Argentina and Chile on toothfish (Dissostichus eleginoides), show potential for improved cooperation [37]. From a purely ecological perspective, a collaborative management strategy appears promising. However, the sovereignty disputes over the Islas Malvinas/Falkland Islands, makes the area one of the most geopolitically and environmentally challenging fishing grounds in the world.

Data gaps limit effective conservation and fisheries management

Effective conservation and management of fisheries in the SWAO is constrained by persistent data deficiencies. For example, species of conservation concern in the region, like sharks, have limited observational data [3], the understanding of the structure of reef fish assemblages is limited to specific sub-regions [38], deep-sea ecosystems are virtually un-explored by visual coverage [39], and fisheries data are often incomplete [40]. All of these limitations have implications for regional efforts to protect marine biodiversity and sustainably manage fisheries.

A critical obstacle for realizing management, including cooperative management, is the pervasive lack of reliable and consistent data on fisheries throughout the region, especially for SSF, which are chronically underreported across Latin America and the Caribbean [40]. While not exclusive, this overall data deficit can be exemplified in the SWAO by SSF of northern Brazil [41]. Brazil’s systematic data collection has been inconsistent since the early 2010s, largely due to institutional instability [41]. From 1990 to 2007, the Brazilian Institute for the Environment (IBAMA) coordinated national fisheries statistics with broad coverage [42]. However, multiple subsequent reforms shifted responsibility to new agencies, disrupting data compilation and resulting in a near-complete national halt [41]. Since then, no sustained national-level program has been restored, and information is largely piecemeal from state or academic initiatives concentrated in Brazil’s South/Southeast, leaving the North and Northeast, where SSF surpass industrial catches and underpin local food security and livelihoods, severely under-monitored [43–45]. In the absence of systematic monitoring, the extent of such connectivity (and the status of additional shared stocks) remains poorly resolved, impeding coordinated governance and climate-ready management. This reality has further implications for the management of transboundary stocks in the North/Northeast SWAO Brazil and the Guianas shelf such as seabob shrimp (Xiphopenaeus kroyeri) and acoupa weakfish (Cynoscion acoupa) [46, 47].

Climate change further amplifies existing challenges

Climate change is already reshaping the oceanographic and ecological fabric of the SWAO, with most of the region having undergone substantial surface warming during the past four decades [7, 48] (Fig. 3a). Compound events of marine heatwaves, high acidity and low chlorophyll have also increased rapidly in the equatorial and South Atlantic recently [49]. These climate-driven ecological shifts are already inducing profound economic, social, and environmental changes in the SWAO. For example, the intensification of the Brazil Current [7, 24] is altering the spatial distribution of fish and shellfish assemblages along the Brazilian and northern Argentine–Uruguayan shelves, increasing the prevalence of warm-water species while reducing cold-water components. Catch records and observational data reveal a tropicalization of fisheries, with warm-water species becoming more prevalent while cold-water species decline, reflecting poleward shifts in distributions [50, 51].

Fig. 3.

Projected climate change impacts in biodiversity and shared stocks in the Southwest Atlantic Ocean. a Linear sea surface temperature (SST) trend (°C/decade) for the period 1982–2020 (data from National Oceanic and Atmospheric Administration—National Climatic Data Center Optimal Interpolation SST version2 Advanced Very High Resolution Radiometer). b Changes in species richness projected by 2050 data from AquaMaps/AquaX [15]). c Shifts in transboundary stock share proportion across EEZs by 2050 (adapted from [52]). d New arriving stocks by 2100 (adapted from [53]). e Shifts in straddling stocks share ratio across EEZs and the high seas by 2050 (adapted from [54]). All projections representing a high emission climate change scenario

Future climatology in the region will continue to change albeit with a high level of uncertainty. For example, future projections show a weakened Atlantic Meridional Overturning Circulation (AMOC), resulting in a warmer South Atlantic (surface and subsurface) with a medium degree of uncertainty [24, 55]. Moreover, future changes in surface wind patterns may alter mixing between major SWAO currents and vertical mixing processes, with potential impacts on nutrient fluxes to the upper ocean, biological connectivity, species distributions, and fisheries. Indeed, ecosystem models project that, within the twenty-first century, environmental dynamics will re-shape species richness patterns, requiring prioritization efforts to safeguard biodiversity in a changing climate (Fig. 3b). Consequently, fisheries management will be challenged by shifts in the distribution of commercially important transboundary species southward (Fig. 3c). This includes the emergence of new shared stocks across EEZs (Fig. 3d), as well as the shift of straddling species into the high seas (Fig. 3e) [52–54]. For example, Fig. 3e illustrates how climate change could shift the proportion of straddling stocks’ distributions between the high seas and EEZs. These potential changes (e.g., a stock moving away from the EEZ by increasing its proportion in the high seas) reduce the effectiveness of unilateral management measures, increases exposure to IUU fishing (e.g., from distant-water fleets), and heightens the risk of governance conflicts, as stocks progressively move beyond national jurisdictions. Addressing these challenges will require adaptive and collaborative management strategies capable of responding to the shifting dynamics of straddling stocks across political boundaries, ideally thorough the establishment of a regional governance body aligned with international frameworks like the BBNJ Agreement and the United Nations Framework Convention on Climate Change (UNFCCC).

Moving forward

At a time when the ocean faces unprecedented challenges from anthropogenic activities, multilateralism is being eroded by geopolitical tensions, and societies worldwide are experiencing growing polarization, the ocean remains both a connector and a shared interest for humanity [56]. Integrated, collaborative ocean governance is no longer an option but an urgent necessity to halt ecosystem degradation and foster long-term sustainability [37]. While governance, conservation, and data collection efforts in the SWAO remain limited, similar constraints are observed even in comparatively data-rich and institutionally developed regions. The key challenge in the SWAO is therefore not the absence of capacity per se, but the lack of coordinated, regional-scale mechanisms that align existing scientific knowledge, monitoring efforts, and governance instruments across jurisdictions. Thus, the political momentum in Latin America can benefit ocean governance by transcending geopolitical borders and sectoral divides, while acknowledging that ecological and climatic processes operate at scales far larger than national jurisdictions.

Build on the Latin American political momentum

The timing for initiating regional dialogues on the establishment of cooperative frameworks and repositioning the SWAO region within the global ocean governance landscape could not be more critical. While geopolitical tensions are eroding aspects of global multilateralism, this trend may also create space for strengthened global and regional governance initiatives as exemplified by the recent agreement between the South American trade bloc (MERCOSUR), and the European Union on agriculture. An agreement that started negotiations over 20 years ago [57]. In the SWAO, emerging narratives increasingly frame regional cooperation not only as a response to global governance gaps, but also as an opportunity to assert strategic autonomy and shared stewardship over marine resources [8]. Moreover, Brazil is currently at the central stage for the global environmental agenda, hosting and set to host a sequence of international meetings, including UNFCCC Conference of the Parties (COP) 30 in Belém in November 2025 as well as the 3rd Symposium of the BBNJ Agreement in March 2026 and the UN Ocean Decade Conference in Rio de Janeiro in 2027, among others. COP30 in particular amplified the urgency of climate-ocean linkages, reinforcing the need for integrated adaptation strategies to address warming seas, shifting fish stocks, acidification, and biodiversity loss [58, 59]. Brazil, during the 3rd UN Ocean Conference (UNOC3) in Nice, France (June 2025), integrated a network of countries that launched the Blue National Determined Contributions (NDCs) Challenge, a global call for countries to include the ocean in their national action plans and climate ambitions. A key Blue NDC strategy is to foster sustainable and climate-resilient fisheries, grounded in ecosystem-based management and integrated risk frameworks. In parallel, with the BBNJ Agreement ratified in January of 2026, and Chile actively pushing to host its permanent secretariat, transforming diplomatic opportunities into concrete strategies on fisheries, conservation, and climate resilience that serve regional and global interests could become a reality. Finally, the UN Ocean Decade Conference further underscores the role of ocean science diplomacy as a bridge between knowledge production and policy action, aligning with the global call for transformative, science-driven solutions.

These events represent not only milestones in global environmental diplomacy but also a rare alignment of opportunities for the region to consolidate a coherent strategy for the SWAO. Countries can use these events to articulate shared priorities, negotiate cooperative frameworks, and strengthen commitments to ecosystem-based and climate-resilient management. International agreements, such as the PSMA and the BBNJ Agreement, offer ready-made platforms that can be adapted to regional realities, providing legitimacy and enforcement capacity for RFMOs. The urgency lies not only in responding to accelerating environmental change but also in seizing this historic diplomatic momentum to advance a systematic, science-based, and regionally grounded agenda for ocean governance, including the SWAO.

Strengthen ocean science diplomacy

Moving forward requires a paradigm shift in the governance framework in the SWAO. Specifically, the foundation for cooperation, sustainable fisheries governance and conservation requires a systematic approach to procedural ocean science diplomacy that integrates climate change considerations, harmonizes fragmented regimes, and strengthens the role of science [60].

Ocean science diplomacy offers a useful lens for understanding and potentially bridging these divides [61]. By positioning science as both a source of knowledge and a tool for management, ocean science diplomacy seeks to reconcile sovereignty imperatives with the need for cooperative governance in a fragmented institutional landscape. ICCAT illustrates this paradox. While it represents an important forum for transnational collaboration, it has faced criticism for limited effectiveness in ensuring sustainable tuna management, despite hosting mechanisms for evidence-based decision-making [62]. This demonstrates both the opportunities and shortcomings of existing RFMOs that provide structured arenas for diplomacy but are undermined by scientific and procedural asymmetries across regimes. Strengthening science–policy interfaces can help translate complex environmental signals into actionable management strategies. In this context, ocean science diplomacy can reconcile sovereignty concerns with cooperation by positioning knowledge as an active tool of negotiation. Shared monitoring systems, harmonized methodologies, and joint assessments will be essential for generating robust, comparable data.

Climate change makes this integration even more urgent, as shifting stocks and ecosystem transformations transcend borders, demanding coordinated responses. A solution capable of addressing the complexity of multilateral concerns demands embedding fundamental cooperative frameworks and behaviors to raise trust in the institutional agencies, as well as assuming a shared vision. Such an approach would foster science-based spatial regional approaches to coordinate sustainable management and conservation of transboundary species. This implies moving beyond single geographical criteria toward prioritizing shared challenges across ecologically similar regions increasingly affected by ocean warming. Those threats span multiple dimensions, including institutional human and financial resource availability, stakeholder interests, market dynamics trend, policy frameworks, cultural practices, and species-specific vulnerabilities, requiring negotiations that strengthen convergence towards shared goals and openness to innovation to manage dynamic challenges in the midterm. In the face of geopolitical tensions, science diplomacy can create neutral arenas where states can collaborate towards shared goals.

Despite clear benefits in terms of coordination and sustainability, feasibility of this transformation remains contingent on political will, sovereignty sensitivities, and the ability to reconcile distinct national priorities. Leveraging the region’s long-standing record of scientific cooperation and the precedent set by earlier mechanisms, the development of a renewed institutional framework could serve as a pragmatic and effective first step to foster more integrated and cooperative ocean science in the SWAO. By moving beyond isolated research efforts toward a regional and institutional collaboration built on a shared vision, mission, and long-term agenda, scientists could help draw the path for an integrated SWAO. Importantly, as engaged researchers, there is no need to wait for the crosswinds of the political system to change. Collective scientific initiatives can push this agenda forward through shared data infrastructures, the development of joint research expeditions, harmonizing monitoring protocols, and promoting capacity-sharing programs that bridge institutions across the region. The revitalization and implementation of ZOPACAS, for instance, could provide a promising platform to foster scientific cooperation on ocean-related issues, including fisheries research in the SWAO [63]. Similar science-based collaboration has the potential to strengthen regional governance and promote shared stewardship of the SWAO’s marine resources. For example, in 2024, a group of scientists (including authors of this paper) met at the 20th Congreso Latinoamericano de Ciencias del Mar (COLACMAR) under the auspices of the Asociación Latinoamericana de Ciencias del Mar—(ALICMAR, https://www.alicmar.org/) in Brazil, to discuss precisely the themes explored here, from a scientific perspective. Given its long-standing role as a regional scientific organization, ALICMAR could also serve as a foundation for boosting collaborative ocean governance in the SWAO. Research in ocean science diplomacy shows that scientific cooperation can support regional governance enhancement by fostering trust, shared knowledge, and capacity-building. While we cannot guarantee that scientific integration will ripple into governance reforms, it encourages coordination across jurisdictions and highlights the mutual benefits of working together toward ocean sustainability.

Advance integrated and multi-scale ocean governance and management

Ocean governance in the SWAO remains fragmented, largely confined to bilateral agreements or sectoral mandates that fail to capture the ecological connectivity and socioeconomic interdependence of the region. Such fragmentation contrasts with the presence of broader regional integration frameworks, such as the MERCOSUR which, despite mixed results, have provided institutional spaces for cooperation in selected non-ocean policy domains. Despite these broader frameworks, the most urgent gap in ocean governance in the SWAO lies in the absence of a cooperative framework that meaningfully integrates Brazil with existing bilateral arrangements between Argentina and Uruguay. This suggests that the constraints on regional ocean governance extend beyond the absence of regional institutions alone. Experiences from other regions such as the Association of Southeast Asian Nations (ASEAN) and WCPFC further suggest that incremental, confidence-building cooperation, is possible even in contested maritime contexts, offering potential lessons for ocean governance, even beyond the fisheries sector. Given the ecological connectivity of shelf systems and the transboundary nature of key stocks, a regional, but flexible and polycentric, approach represents a viable pathway to confront the challenges facing the region. Such framework should be anchored in science-based and adaptive management, strengthened data sharing, and inclusive participation of stakeholders and local communities. This transformation will not occur overnight; it demands time to cultivate the necessary capacity and institutional strength, yet long-term persistence in regional cooperation can yield results even amid difficult geopolitical circumstances. It must also be enabled by a plausible, actionable and fair pathway, and anchored in a long-term vision and regional research agenda. Far from threatening sovereignty, the establishment of a regional organization for cooperative governance (e.g., RFMO) could strengthen it by providing Argentina, Brazil, and Uruguay with a united front to defend their shared resources. Moreover, while the lack of regional cooperation organization maintains sovereignty and autonomy in each State, it undermines resilience to climate change, governance gaps, and the advance of distant-water fleets [31]. Thus, effective governance in the SWAO cannot be limited to coastal States alone. The growing presence of distant-water fishing fleets, particularly from China, Spain, and Taiwan exploiting straddling stocks in adjacent high seas areas, requires negotiated engagement with extra-regional actors through existing international instruments such as the BBNJ Agreement [31].

Ocean management in the region should aim for adaptive and ecosystem-based management measures that enhance the resilience of ecosystems and fish stocks to climate change [64]. The concept of climate-resilient management is grounded in precaution, efficiency, and policy responsiveness, and is designed to address uncertainties and the responses of marine social-ecological systems, while considering the integration of policies, tools, and measures across space and time [65]. Thus, it must be inclusive of diverse stakeholders such as academia, small-scale fishers, industry, and Non-Governmental Organizations in order to establish formal spaces to weave plural knowledge systems and aspirations. The bioregionalization of coastal and shelf areas [4] provides a robust macroscale framework to strengthen social-ecological and institutional fit. Applying this approach to the SWAO can identify sensitive habitats and vulnerable ecosystems, guide targeted management measures, and reveal ecological drivers currently masked by fragmented observations. Aligning institutional structures with these large-scale environmental dynamics would foster more effective regional management, resilient fisheries, and enhanced biodiversity conservation. For example, as SWAO countries expand their marine protected areas (MPAs) to reach their 30 × 30 goals under the CBD, regional conservation can be strengthened through the establishment of a broad network of transboundary MPAs. Building on the large MPAs already designated in Argentina and Brazil, a SWAO conservation network could enhance biodiversity protection, help recover overfished stocks, sustain ecosystem services, increase ecological connectivity and foster resilience to a changing climate [66]. While these large MPAs represent significant conservation achievements, they also intersect with geopolitical and sovereignty dynamics (e.g., the Islas Malvinas/Falkland Islands dispute). As such, conservation initiatives can simultaneously advance biodiversity objectives while complicating regional cooperation, highlighting the need for conservation strategies that are ecologically sound, politically aware, and regionally inclusive. Moreover, such a network should also be connected to the high seas through the BBNJ Agreement, and could include areas already designated as CBD’s Ecologically and Biologically Significant Areas, such as the Atlantic Equatorial Fracture Zone (https://livinghighseas.org) or the Blue Hole, a highly productive zone just off Argentina’s EEZ under intense fishing activities carried out by distant water fleets [67, 68].

Author contributions

Conceptualization: JPA, FLL Visualization: JPA Writing—original draft: JPA, FL, LGC, OD, IG, AJJ, PFML, JAAP, NIPP, ARP, AP, LFP, MS Writing—review and editing: JPA, FL, LGC, OD, IG, AJJ, PFML, JAAP, NIPP, ARP, AP, LFP, MS.

Funding

JPA, NSERC Discovery Grant and SSHRC Partnership Grant PFML, CNPq productivity grant (302365/2022–2) and the Romanian Ministry of Research, Innovation and Digitalization (#760054–JUST4MPA), within the PNRR-III-C9%-2022–I8 call LFP CNPq (405607/2023–7), FAPERJ (E-26/210.291/2024), and UERJ-PROCIENCIA grant.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.