The methodology was applied at six test sites (Baltic Sea, Mediterranean, Atlantic (Azores), Atlantic (Bay of Cádiz), Black Sea and North Sea). It should be noted that each test site has tailored the methodology to fit their local context and objectives as advised.
Cádiz Bay had as a goal to address conflicts within the nominal MPA of the Bay of Cádiz. Despite strategic objectives, the MPA lacked effective implementation, leading to challenges in achieving consensus on solutions among stakeholders from various sectors. Trade-offs, such as that between marine conservation and economic development, highlighted the need for a robust governance framework. The workshop emphasised the importance of examining past initiatives, enhancing surveillance, and starting with more straightforward issues. SeaSketch, a participatory mapping tool, showed promise in the context of the growing blue economy but faced challenges in small MPAs. The overall experience underscored the vital role of effective governance and strategic planning for successful MSP in the region.
The Azores involved representatives from various sectors aiming to support the creation of a new protected area. Utilising the SeaSketch tool, participants identified conflicts, potential uses, and perceptions related to climate change. Trade-offs were discussed, including conflicts between marine conservation and economic development, highlighting the importance of integrating new members into the CoP and the need for more resources for effective participatory mapping in the growing blue economy.
The Belgian test site had two objectives: proposing a marine reserve in the Belgian part of the North Sea and addressing trade-offs and considerations for pelagic biodiversity protection. The workshop successfully facilitated trade-offs, ecological protection, and discussions on coastal management. Challenges included tool applicability and potential stakeholder fatigue. Challenges involved the dynamic nature of the maritime decision-making system, but the workshop provided valuable insights and highlighted the importance of addressing uncertainties in planning.
The Western Mediterranean test site concentrated on marine mammal conservation, aiming to extend the network of strictly protected areas (SPAs). The workshop used various environmental features and ecosystem service layers, identifying challenges related to large cetacean species, maritime traffic, and collision risks. Recommendations included relying on existing initiatives, developing criteria for SPA design, and recognising the complexity of marine mammal protection.
In the Black Sea test site, the CoP workshops explored conflicts and potential uses in the Bulgarian test site, focusing on extended MPAs and offshore wind farm development. Trade-offs involving marine conservation, economic development, and ecological integrity were discussed. Challenges included defining clear trade-off arguments, and recommendations emphasised the need for integrated MSP, improved planning measures, and transnational/cross-border MSP.
In the Baltic Sea test site, the CoP workshops focused on identifying and analysing conflict areas for expanding MPAs in Gdansk Bay, Poland. Participatory mapping highlighted conflict areas, with tourism expansion posing challenges. Insights underscored the importance of data availability, stakeholder knowledge, and leveraging existing research for informed decision-making. Challenges included the lack of data on the impact of tourism, suggesting a need for further research.
In the context of the case site results, the term ‘highlight’ indicates that the trade-off was a central topic in discussions among stakeholders
Involvement of the stakeholders
In the context of MSP, as defined by ref. 33, “stakeholders are individuals, groups, or organisations that are (or will be) affected, involved or interested (positively or negatively) by MSP measures or actions in various ways”. Stakeholder analysis is one of the essential components of effective MSP, facilitating sustained stakeholder engagement in a manner that promotes long-term exchanges34. These exchanges are central to clarifying the arguments that each stakeholder is willing to discuss and trade-off (trade-off arguments are analysed in detail in section Analysis of trade-off arguments below).
First, the individuals involved in the study were active members of established CoPs. However, certain case studies, as illustrated in 1, adopted a more inclusive strategy, as exemplified by Cádiz, which extended its participation to additional stakeholders interested in the region. This broader approach was driven by Cádiz’s goal of gathering fundamental information and establishing a framework. For the Azores and the North Sea test sites, new members were incorporated into the CoP. In the other case studies, CoP members were predominantly present at the meetings, with only a few notable absences.
This highlights the diversity of approaches taken by different case studies regarding stakeholder participation. The proposed methodology holds the potential to enhance stakeholder interest and participation, facilitating collaborative development of the ecological-socio-economic (ESE) framework.
Even if the process takes time and resources, the stakeholders’ participation is crucial as it encourages social acceptance, reduces conflicts and increases trust between the partners35. The decisions concerning the MSP also address one of the uncertainties in planning: ambiguity. Ambiguity is defined by multiple knowledge frames or different but (equally) sensible interpretations of the same phenomenon, problem, or situation36. Ambiguity is often led by vague legal/policy formulation37.
Furthermore, Pomeroy et al.34 highlight that “stakeholders must be defined broadly to capture a wide range of groups and individuals, it is important to note they are also often dangerously simplified, suggesting that interests, experiences, needs and expectations are homogenous among a given group of people”.
Nevertheless, some test sites highlighted the risk of stakeholder fatigue and work duplicated. Furthermore, some CoP members express the need for more time to prepare and discuss results, citing low digital skills and difficulties organising online or hybrid events. Indeed, as Zaucha et al.35 highlight, stakeholder participation has costs. For these authors, the main ones are the need for larger financial and human resource capacities, a longer preparation period for planning solutions, the risk of losing control over the MSP process by the authorities, and the risk of the process being dominated by the government or by private interests.
Ecosystem services map
While the methodology proved consistent and applicable, only the Baltic Sea test site chose ecosystem service mapping due to existing geo-referenced data. In the Western Mediterranean, criteria and indicators were employed for discussion. One reason for this choice was the time available. Since the assistance for ecosystem service mapping was not initially included in the project’s scope, support from the UAc team only became available in October.
Furthermore, the lack of training in various test sites also contributed to the non-utilisation of the ES map, as it requires advanced geomatic skills and spatial data manipulation. Additionally, inadequate data, including geo-referenced, high-resolution, quantitative, and bio-physical data, posed challenges for efficient ES mapping, especially in marine environments. The incomplete knowledge and uncertainties about planning stem from this data deficiency, as highlighted by Ounanian et al.36. Lastly, understanding the concept of ES is crucial, with Bitoun et al.38 emphasising that challenges arise from a lack of comprehension, particularly when adopting recent ES concepts.
This involves mapping the biophysical characteristics of ecosystems that contribute to the provision of ES. To create this type of ES mapping, all available information on the components of the ecosystem is aggregated. This method will aggregate the binary assessment of the contribution of the ES for each ecosystem component. In this binary scale, 0 represents no or negligible contribution of the ecosystem component to the ES, while 1 corresponds to a situation where the ecosystem component contributes to the service in an important way. This method will, therefore, highlight the areas with the most potential ES 20,21.
This method has the advantage of being simple to use and requires limited human and time resources. However, the disadvantage is that it is not robust. Indeed, it only considers the presence or the absence of information about the ecosystem to produce the map. In addition, each component of the map is considered to be equal, which means that the accuracy of the information represented is reduced 20,21. Furthermore, this method will only represent biophysical aspects and will not represent the socio-economic criteria of ES.
Definition of goals
This Section serves to ensure that clear objectives are establish in all case sites or Trade offs Processes. The various testing locations share common goals, albeit with some variations. In terms of similarities, all sites have a common concern for conflict mapping, aiming to identify areas where human activities conflict with marine conservation objectives. Additionally, each site involves diverse stakeholders, ranging from regional governments and NGOs to industry representatives, fishermen, and tourism agents. This inclusive approach seeks to integrate a variety of perspectives into the decision-making process.
Overall, most sites have goals related to marine conservation, whether through the creation of new protected areas, extension of existing networks, or resolution of conflicts to ensure sustainable ecosystem management. As highlighted by Halpern et al.23, one of the main objectives of conservation is to identify optimal allocations of actions in space, but also in time. It is therefore logical that the main objectives are related to conservation and areas that minimise conflict between conservation and human activities.
However, notable differences exist among the testing sites. In Cádiz, the emphasis is on strategic goals, such as placing the MPA on the political agenda, while other sites focus more on operational goals, such as creating or extending protected areas.
In the Western Mediterranean region, there is a specific focus on the conservation of marine mammals and their interactions with maritime traffic. Indeed, as the aim of MSP is to deliver sustainable development in the marine environment, and as the impact of maritime traffic is an anthropogenic threat to the marine mammals in the Western Mediterranean region, MSP therefore allows human activities and protection of cetaceans to be linked 39,40.
The Azores give particular attention to perceptions of climate change, illustrating a specific concern for long-term environmental impacts. Understanding the perception of the stakeholders allows an understanding of political realities that may not be published in the academic literature. Furthermore, it will also help to provide best practice advice for decision-makers in future design, monitoring, and management 41,42.
The Black Sea (Bulgarian) site is distinguished by its examining of potential conflicts related to offshore wind farm development, highlighting specific considerations related to renewable energy. Indeed, renewable energies, as one of the fastest-growing new uses of the ocean, can be used as a catalyst for the MSP process10.
Finally, the Belgian North Sea carried out two distinct trade-off analyses with distinct focuses, one emphasising the creation of marine reserves and the other prioritising pelagic biodiversity and marine habitat management.
In summary, while all testing locations share common concerns about marine conservation and conflict resolution, each project tailors its approach specifically to its region’s unique characteristics and challenges, reflecting a personalised and contextualised approach to sustainable marine management.
Data layers used
Each test site undertook the task of describing the used data layers for: (a) the actual area – an existing/established MPA or other area-based management protection measure, (b) the proposed area – an area with biodiversity needing protection, and (c) climate change – areas with environmental future characteristics similar to (a) and/or (b).
As highlighted by Ehler & Douvere (2009)33, gathering and organising spatially-specific databases typically constitute the most time-intensive phase of planning and management endeavours. Different types of sources for these data can be used: scientific literature, expert scientific opinion, government sources, local knowledge and direct field measurement33.
Two distinct approaches were observed for the actual area layers. Cádiz Bay and the Azores employed a participatory method, with sectors or users identifying crucial areas. This approach using local knowledge can promote adaptability in decision-making, support environmental justice, reduce governance rigidity, and improve acceptance and uptake43. In contrast, other sites, including the North Sea, utilised existing environmental/ecosystem layers and marine space usage.
Examining conflict areas in the proposed zones involved stakeholders’ input, with West-Med employing specific criteria through Important Marine Mammal Areas (IMMAs) data analysis. The participatory mapping of conflict clarifies the conflict condition, generates spatial data, and produces solutions to facilitate consensus-building44.
Climate change will provoke changes in ocean conditions, while the structure and functioning of marine ecosystems will lead to changes in the distribution and intensity of ocean-related human uses45. Indeed, ocean ecosystems are particularly vulnerable to climate change46. Therefore, integrating climate change is necessary to “contribute to ocean sustainability, anticipating future changes in marine social-ecological systems, ameliorating negative consequences for societies, lessening anthropogenic impacts on ecosystems, and promoting the equitable flow of benefits”47.
The different test sites, therefore, add climate change in their participatory survey. Two methods could be distinguished: the use of climate models, used by NW Med, Black Sea and the use of perception, used by Cádiz Bay, Azores, and the first survey of the North Sea, while the Baltic Sea did not include such layers (2). Cádiz Bay focused on identifying sensitive areas based on risks to population, infrastructure, sector activities, and environmental conservation. Azores assessed climate change through questions on likelihood, impact, and effects on ES. The North Sea spatialised the impact of climate change.
Choosing the climate change modelling approach allows the estimation of alterations in marine ecosystems and human uses resulting from climate change and is helpful for MSP design45. Nevertheless, one challenge of this method is the lack of consistent databases, climate change models, and the corresponding validation of simulated results for all sectors studied41.
Addressing the perception of climate change is important as the perceptions of the impacts depend on the socio-economic context. Furthermore, it allows an understanding of stakeholders’ feelings, their knowledge of the subject, and their knowledge of the local context that is not in the scientific literature 41,42.
Analysis of trade-off arguments
With finite marine and coastal resources, MSP faces the challenge of allocating space and usage efficiently among competing sectors such as shipping, fisheries, aquaculture, biodiversity conservation, and renewable energy. The trade-off analysis can therefore navigate conflicting objectives and strike a balance that optimises resource utilisation while minimising negative impacts12,38. As highlighted by Zuercher et al.48, “trade-offs are an inevitable, yet complex, reality of any multi-sector, multi-objective planning process”.
To complete the trade-off analysis, each test site had to describe the arguments used for the established trade-offs offered in the partners guidelines (Fig. 1)22. Trade-off analysis can help evaluate activities that share common resources, enabling the exploration of various configurations for the planning and distribution of marine activities49. This argument portfolio was used to provide the different arguments, as well as a common definition so that each test site would have the same frame of reference Fig. 2.
Use of trade-off arguments and constitution of the discussion group for each test site extracted from deliverable 4.3 MSP4BIO.
Climate change consideration (perceptions of models) and the use of ecosystem mapping for MSP4BIO test sites extracted from deliverable 4.3 MSP4BIO.
The management of the trade-offs begins when it is not possible to compromise with objectives from very different dimensions, such as economic, social, and environmental, etc. Trades-offs occur between these different dimensions, but also inside the dimensions themselves50. As highlighted by Lester et al.12, it “can reveal inferior management options, demonstrate the benefits of comprehensive planning for multiple, interacting services, and identify ‘compatible’ services that provide win-win management options”.
Figure 3 shows that every test site has one argument in common: conservation and economic development. This trade-off means finding the right balance between sustainable practices and allowing economic growth while minimising environmental harm. The fact that this trade-off is common in every test site is logical. Indeed, dealing between conservation and economic goals is one of the main objectives of MSP and conservation23.
Trade-offs arguments extracted from deliverable 4.3 MSP4BIO.
The West-Med and North Sea 1 highlighted two arguments: trade-offs between short-term and long-term benefits, and trade-offs between local and regional interests. Opting for short-term benefits can provide immediate gratification or economic advantages but may come at the expense of long-term consequences24. In the case of the West-Med, mitigation measures to minimise ships’ impact on mammals could consist of traffic deviation or speed limitation. These measures could have an important economic impact on the sector and there are few arguments to lower or compensate for it. A cetacean presence alert broadcast could be a way to lower the economic impact by enforcing mitigation measures only when it is needed.
Concerning the second argument, the two test sites agree with the fact that it may be more interesting to think on a larger, transnational scale to be efficient. Indeed, many issues and sea uses are not found only within national borders51.
About the trade-off between exclusive uses and shared uses, Cádiz Bay and the Azores highlighted this argument. The trade-off between exclusive uses and shared uses relates to the allocation of resources or spaces and the choice between restricting access to a select few or opening them up for the broader group. The challenge is to create policies that reconcile exclusive and shared use, serving the interests of diverse stakeholders.
Only the Azores choose specific stakeholders. Each stakeholder has specific interests and needs in marine spaces, and managing these competing interests requires careful consideration and trade-offs. Indeed, the interests of recreational boaters and tourists can come into conflict with conservation interests. This access can be managed by conditioning how it is done, making it less devastating for the marine ecosystem.
The Bay of Cádiz highlighted that the difficulty of this exercise also concerns illegal activities, because even if they are not authorised, they are accepted, and therefore do not give the impression that there are any conflicts. This proves, as highlighted by Turkelboom et al.11, that the analysis of trade-offs argument shifts from formal scientific data to informal and implicit knowledge possessed by the stakeholders.
Even if there are some trade-offs in common with each test site, this exercise highlights the difference in trade-offs analysed between the test sites. As highlighted by Lester et al.12, trade-offs are context-specific and depend on the particular circumstances of each MSP process.