We developed an initial list of stakeholders for Southern Ocean ecosystems from the stakeholder list for the Marine Ecosystem Assessment for the Southern Ocean (MEASO) Science Network (Constable et al. in preparation). Other stakeholders were added iteratively to the stakeholder list if they were mentioned in the strategic reports and websites of stakeholders already on the list. Key players in unrepresented industries on the MEASO Science Network, such as the largest private fisheries in the Southern Ocean, and governing bodies in the fisheries and tourism industries, were also added to the list (Commission for the Conservation of Antarctic Marine Living Resources, 2019). In total, 64 stakeholders with an interest in Southern Ocean ecosystem management were identified. Of these, 29 stakeholders are sub-groups or sub-organizations of a parent stakeholder (e.g., SC-CAMLR is part of CCAMLR but plays a significant role as a specific body), but were analyzed separately due to their own interests in, or influence over, specific ecosystem services.

We identified the ecosystem services present in the Southern Ocean based on research by Grant et al. (2013), which explored provisioning, regulating, supporting and cultural ecosystem services (following the Millennium Ecosystem Assessment framework for ecosystem services; Millennium Ecosystem Assessment [MEA], 2005; Table 1).

We then conducted a thorough analysis of the stakeholders’ motivations, interests, aims, actions and strategies, to understand their connection to ecosystem services in the Southern Ocean. This was done through close reading of annual reports, strategic plans, and key documents listed on organizational websites for our list of stakeholders (these resources are detailed in Supplementary Table 1). The scope of webpages and documents examined to understand each stakeholder’s motivations, interests, aims, actions and strategies varied; this depended on each stakeholder’s information management on their website, and where specific information was located.

We linked each stakeholder to the specific ecosystem services they have an interest in. Stakeholders were defined as having an interest in an ecosystem service if they have one or more of the following relationships with it: produce, use, regulate, research, monitor (note here that the ‘regulate’ relationship refers to management, and can be for any ecosystem service, not just ‘regulating’ services). The ‘produce,’ ‘use,’ and ‘regulate’ relationships were determined following the methodology used by Raum (2018) in categorizing forest management stakeholders into these three groups based on their functional roles. The ‘research’ and ‘monitor’ categories were added for our Southern Ocean context to differentiate stakeholders whose relationship to ecosystem services is purely research, versus those who do not undertake research directly (i.e., non-research scientific organizations) but instead undertake monitoring and assessment activities.

We created an interest-influence matrix to explore in greater depth the relationships between stakeholders and ecosystem services (following Raum, 2018; see Supplementary Table 2). Stakeholders’ levels of interest and influence were categorized as low, medium, or high. The level of interest in an ecosystem service was determined by how closely stakeholders’ actions aligned with a particular ecosystem service (following Raum, 2018). The level of influence was defined as the ability a stakeholder has to affect specific ecosystem services, either directly or indirectly, through use, production, regulation, research and/or monitoring.

To summarize the interest-influence matrix, we categorized stakeholders under their broad industries, as science organizations (research, ecology, or monitoring organizations), regional bodies and regulators, international bodies and regulators, fisheries, lobby groups, or tourism and the public. Using the interest-influence matrix, we also assigned them functional roles based on their work with particular ecosystem services, as producers, users, regulators, researchers, or observers, following Raum’s (2018) process:

We used a network mapping approach to visualize the relationship between stakeholders and ecosystem management, in particular the decision-making process. First, stakeholders in their broad industries were mapped against the four key types of ecosystem services – provisioning, regulating, supporting, and cultural – based on their functional role toward, and level of interest in, these ecosystem services (Figure 1). The aim of this network visualization was to identify: (i) the relative strength of connectivity between stakeholders and each of the four key ecosystem services, and (ii) whether any services were under-represented or over-represented in terms of connection to stakeholders.

We then visualized the relationship between stakeholders to understand how various stakeholders regulate, advise, fund, and support one another. Individual stakeholders were separated based on their functional role to understand how stakeholders with different roles interact with each other. To reduce overlap in the network visualization, some stakeholders were grouped together with their parent stakeholders when they performed the same roles and had the same level of interest in ecosystem services (for example, the SC-CAMLR scientific working groups WG-EMM, WG-SAM, and WG-FSA were grouped together with their parent stakeholder, SC-CAMLR). As a result, 38 different stakeholders or stakeholder groups, including some stakeholders which are sub-groups of others but which perform different roles or have a different level of interest to their parent groups, were included in the network visualization.

Based on these two visualizations, we created a conceptual diagram (Figure 2) to demonstrate the influence pathway between key stakeholder groups, and how ecosystem services influence decision-making.

To contextualize the relationships between stakeholders and ecosystem services, we applied the vrk framework to three case studies of Southern Ocean ecosystem management, following Gorddard et al.’s (2016) approach. The vrk framework, aims to explore the interconnections between values, rules and knowledge in decision-making, to identify assumptions and gaps in decision-making systems and processes (Gorddard et al., 2016). It also explores vrk interactions, allowing for the analysis of the relationship and impact between values and rules, values and knowledge, and rules and knowledge (Gorddard et al., 2016; Table 2).

We selected three diverse examples relating to Southern Ocean ecosystem management as case studies, to understand gaps in decision-making through the vrk framework.

These case studies were chosen to contrast different approaches in Southern Ocean ecosystem management, pertaining to different ecosystem components (1-seabirds, 2-whole-of-ecosystem, 3-primary production). The first two case studies were also selected due to high information availability. We note that while the third case study is not ecosystem management per se, it has a strong link to regulating services provided by Southern Ocean ecosystems, as well as complex challenges for governance and policy, and so was selected as a useful complement to the first two case studies.

We explored each case study by reviewing a combination of primary documents published by the respective body, as well as academic literature evaluating any relevant management decisions. The case studies were analyzed to understand their aims, methods, motivation, social-political context, participants and roles, following the recommended approach of Gorddard et al. (2016). We used this information to then ascertain underlying values, rules and knowledge implicit in the decision-making process. Finally, vr, vk, and rk interactions were explored by critically examining the values, rules and knowledge used in each case study. The process of case study analysis was conducted by one researcher, the vrk framework applied to the output by two researchers, and the overall process scrutinized by the authors’ team as a whole. To visually represent this information, we developed a conceptual diagram (Figure 4) to connect key stakeholders and ecosystem services for each case study, framed through the role each stakeholder played in the decision-making process.

Our analysis of the transactional landscape for Southern Ocean ecosystem stakeholders and ecosystem services indicates that, across the different stakeholder groups, the strongest interest is in provisioning ecosystem services, followed by regulating services (Figure 1; see Table 3 for a list of acronyms in this and subsequent figures). All stakeholder groups have at least some interest in provisioning services, and all groups but fisheries have an interest in regulating services. In contrast, the only stakeholders with an interest in supporting ecosystem services are science research stakeholders, and the majority of the interest in cultural ecosystem services is held by the tourism and public groups (see Supplementary Table 2 for the full categorization of each stakeholder and details regarding their interest in and influence over ecosystem services).

86.9% of ecosystem services relationships are to regulators, researchers, and monitors, with only 13.1% of producer or user relationships between stakeholders and ecosystem services. As a result, there may be an overrepresentation of science viewpoints and values in Southern Ocean ecosystem management decision-making.

Four key types of relationships were identified between stakeholders in Southern Ocean ecosystem management: regulating, advising, funding, and supporting. Producers, in particular the fisheries industry, are the stakeholder group whose actions and behaviors are most governed by the regulator stakeholder group (Figure 2). Some researchers, as well as regulators themselves, are also regulated by other stakeholders.

There appears to be a strong culture of advising among the stakeholders, with many researchers advising regulators, particularly CCAMLR and ATS. Several researchers and regulators have observer status at CCAMLR or ATCM. This allows them to represent their perspectives at decision-making forums. No producers and only one monitor (IUCN) has either observer status or attends CCAMLR or ATCM, suggesting a potential gap in these stakeholder perspectives in decision-making.

Despite the interconnectedness of stakeholders demonstrated in the stakeholder relationships network (Figure 2), the decision-making pathway is distinct, and represents the way in which the value of ecosystem services feeds into decision-making via government, science, and governance, and how users and producers impact ecosystem services (Figure 3). This conceptual diagram is applicable to Southern Ocean ecosystem management, as well as ecosystem management on a broader scale.

Government performs two roles: as the primary funder and supporter of science, and as a regulator of users and producers. In the first instance, government is guided by cultural ecosystem services, which influence what areas of science are funded and otherwise supported. In the case of Southern Ocean ecosystem management, the influence of cultural ecosystem services on funding may differ between nations; some may be more strongly influenced by the values of the Southern Ocean, while others are likely to be more driven by domestic influences. However, the influence of different values may differ based on whether these decisions play out at a national or international level.

Governance takes three forms – policy, soft law, and regulation – and receives scientific advice based on scientific research, which is formulated through engagement with provisioning, regulating and supporting ecosystem services. Governance is also influenced by the actions and priorities of lobby groups.

The vrk framework analysis of three Southern Ocean ecosystem management case studies is summarized in Table 4, and a network visualization particular to the ecosystem services and stakeholders represented in the case studies is shown in Figure 4. This network visualization demonstrates the dual role of science, in researching ecosystem services directly and in IMO, SCAR, and COMNAP providing scientific advice to other stakeholders. In this network visualization, researcher relationships are shown only for scientific research conducted specifically for the case study. Researchers in the Ross Sea MPA case study did not conduct any new research, but engaged only with the existing global body of scientific evidence; for this reason, science researchers are not shown to have a researcher relationship with any ecosystem service. We acknowledge the importance of individual nations as stakeholders in the Ross Sea MPA case study, so have considered four particular CCAMLR member states as stakeholders because of their roles in how decisions were made in this case study.

The remit of CCAMLR is the conservation of Antarctic marine living resources (Press et al., 2019). However, fisheries have been given most of the attention of CCAMLR since the beginning (e.g., Constable, 2011).

Case study 1 emerged with the recognition of high rates of seabird mortality in longline fisheries in the early 1990s, which coincided with rapid declines in those populations. In order to rectify this, decision-making in IMAF initially heavily prioritized ecological and environmental values over social and economic values (Table 4). However, as incidental mortality of seabirds was reduced to zero, conservation measures were loosened to allow fisheries more freedom in operating, suggesting a growing shift toward increasing priority for economic values, although noting that ecological values still take precedent (Croxall, 2008; Waugh et al., 2008).

Case study 2 highlighted the challenges within CCAMLR of addressing questions of biodiversity conservation and the maintenance of supporting ecosystem services. The consensus decision process in CCAMLR and the large number of fishing interests amongst its Members means that provision services have higher attention than supporting services, such as biodiversity. Although the proposal of the Ross Sea MPA was based on ecological values, there was strong prioritization of economic values in the negotiation of the MPA’s boundaries, such that in its adopted form, some of the most productive areas of the Ross Sea remain unprotected, to allow fisheries to operate in these areas (Brooks, 2013; Brooks et al., 2019; Commission for the Conservation of Antarctic Marine Living Resources, 2017; Dodds and Brooks, 2018; Sylvester and Brooks, 2020).

Case study 3 provides an example external to CCAMLR but governed by an international convention that has regulatory power – the London Convention (International Maritime Organization [IMO], 2012). The assessment process for Fe fertilization is guided by science, giving regulators time to understand how to incorporate potential Fe fertilization in the Southern Ocean into carbon markets and international laws (Powell, 2008; Institute for Marine and Antarctic Studies [IMAS], 2019). However, the scientific research framework does not directly include exploration of the important ethical considerations in intervening in the earth’s biogeochemical cycles (because these were out of scope of the research project).

CCAMLR has a remit from its Convention to use the best scientific evidence available (Constable et al., 2000; see also CCAMLR Resolution 31).

Case study 1 is an example of formal knowledge being prioritized over informal knowledge. The risk rating for seabirds in different fisheries, and therefore degree of risk management, for IMAF was based on published scientific information and expert information from CCAMLR’s Scientific Committee and its working groups, particularly on breeding ranges, at-sea distribution – both ecological values – to judge potential overlap with fisheries (Commission for the Conservation of Antarctic Marine Living Resources, 2007). It did not use or rely on knowledge from fisheries or conservation NGOs.

Case study 2 shows the tension between knowledge and values and how, in a consensus environment, some values can be diminished in consideration. Most specific knowledge in the Ross Sea has been developed for advising on toothfish fisheries. Yet, there is a large body of general scientific knowledge indicating its value to global scientific research and for supporting services such as biodiversity and productivity. While the latter would be expected to be given support to be sustained, the dominance of fisheries interests meant that non-ecological values, particularly economic values, were given increasing priority as the MPA declaration process progressed (Sylvester and Brooks, 2020). Through the consensus structure of CCAMLR, Member States have the power to prioritize their own values rather than pursuing satisfactory outcomes across all values.

Case study 3 emerged from a global opposition to uncontrolled waste disposal by dumping in the ocean, recognizing the impacts that pollution has on marine ecosystem services generally. The focus on scientific modeling and critically assessing the ecological and economic dimensions of Fe fertilization gives scientists time to explore unknown variables. Under the circumstances of this convention, regulators require confidence before acting that Fe fertilization will be effective and that any environmental effects are acceptable. In this particular example, social, political, and ethical values have not been considered directly to date.

Case study 1 on IMAF is a clear case where the rules system was built upon the scientific knowledge system, with all reviews of the CCAMLR Conservation Measure (CM) based on satisfactory reduction (elimination) of seabird by-catch. All public discussion is therefore framed around the CMs and by-catch data (Table 4). Scientific and ecological knowledge is prioritized through the rule that all longline vessels fishing in the area must have an independent scientific observer on board who reports on the implementation of the CMs. This is enforced through required compliance with by-catch reduction strategies being part of some fishery permits. Existing fisheries demand a high level of proof of the need and success for new management strategies before enacting them; this knowledge was considered in the implementation of the CM, with an initial focus on enforcing the CMs on new and exploratory fisheries before targeting existing fisheries (Waugh et al., 2008).

Case study 2 on the Ross Sea MPA has a close relationship between maintenance of the MPA and scientific research and monitoring built into the long-term application of the conservation measure. It remains to be seen how science and knowledge will be used in the maintenance of the MPA.

Case study 3 on Fe fertilization has a close relationship between scientific knowledge and future regulation, where both national and international policy and future scientific research will be developed based on environmental and economic analysis. This means it may exclude sociopolitical perspectives in formulating guidelines and rules. Globally, the current focus on ocean fertilization is to generate scientific knowledge, following the 2008 London Convention and London Protocol agreement that legitimate scientific research is the only permitted ocean fertilization activity (International Maritime Organization [IMO], 2012). Although this enables scientific research, this may restrict the participation of stakeholders who bring other knowledge sources, or do not engage in traditional scientific research.

Management to reduce incidental mortality of seabirds in the Southern Ocean (our IMAF case study) is commonly heralded as a successful collaborative conservation project (Croxall, 2008), while the MPA declaration in the Ross Sea region was arguably less successful, given its size had to be decreased in order for it to be adopted (Sylvester and Brooks, 2020). Our analyses suggest that a factor influencing this outcome was the role of social and political values in the MPA negotiation process (as opposed to values around all ecosystem services). Political and social values were successfully considered through the IMAF management process, by focusing implementation based on the values of different sub-sets of fisheries (Croxall, 2008). Although political and ethical values are acknowledged in research relating to potential geo-engineering through iron fertilization in the Southern Ocean, they are not explored directly as part of the research. Assessment of ethical and political aspects of iron, alongside ecological and economic assessment, might help ensure that scientific knowledge can be successfully implemented in rules whilst navigating trade-offs in political, ethical and economic values.

Across the three case studies analyzed, the stakeholders engaged were heavily invested in provisioning ecosystem services (Figure 4). This is in line with our analysis of the stakeholders across Southern Ocean ecosystem management more generally (Figure 1). The Ross Sea MPA process involved stakeholders who have an interest across three different ecosystem services; however, our analysis suggests that working with stakeholders who are interested in a variety of ecosystem services must be coupled with incorporating many different values in order for management decision-making to be more successful in collaboration and conserving the ecosystem.

The need for effective management and robust decision-making for Southern Ocean ecosystems will become more important as the global climate continues to change (Constable et al., 2017; Meredith et al., 2019; Cavanagh et al., 2021). The impacts of climate-driven environmental changes pose current and future risks for most Southern Ocean ecosystem services, and these risks will need to be managed to meet increasing demand for fisheries products, tourism and regulating services. Understanding and considering the perspectives, needs and roles of diverse stakeholders in these processes will lead to more robust outcomes for ecosystems and people. Our study is the first to characterize the full transactional landscape for Southern Ocean ecosystem services and stakeholders, and we hope that our analyses, particularly as they relate to emphases and gaps in previous processes, might help underpin effective ecosystem management under future climate change in the Southern Ocean. A remaining challenge is to determine how representative stakeholders of the Southern Ocean are with respect to the wider expectations of civil society and whether the stakeholders can keep pace with their rapidly changing norms.