National Integrated Maritime Policies (IMP): Vision Formulation, Regional Embeddedness, and Institutional Attributes for Effective Policy Integration

Integrated maritime policies (IMPs) provide a comprehensive governance framework to support the sustainable use of the seas and oceans while ensuring a horizon of prosperity for the population of the surrounding coastal regions. This paper focuses on how IMP governance can be arranged to support more effective policy integration. We identify and discuss a number of key strategic and institutional issues which are expected to promote more effective policy integration in IMP development and implementation. First, vision statements of IMPs are scrutinised using the triple bottom line framework and by analysing the process of stakeholder involvement and related public disclosure. Second, we introduce the vision-down plans-up approach on stakeholder participation and management in IMP development to overcome the limitations of the widely used bottom-up and top-down approaches in policy formulation. Third, we analyse the tension between policy convergence and regional embeddedness in national IMPs. We argue that policy convergence does not and should not exclude regional embeddedness. Finally, we study IMP governance changes under the dual lens of time frame and institutional plasticity. The findings provide recommendations for policymakers and stakeholders on key strategic and institutional considerations which should enhance effective policy integration during the formulation and implementation of a national IMP.


Introduction
Sea-related activities are intertwined and interdependent [1]. In this paper, terms such as maritime, marine, sea-and oceans-related are used interchangeably. Fragmented in silo approaches to maritime policy may undermine the formulation of overarching goals and ambitions and may hinder the conciliation process between different maritime uses [2]. Academics argue that a fragmented sector-oriented policy scheme should gradually give way to a more integrated approach [3,4]. Long-established sector-wide policies have made room for more holistic and cross-cutting perspectives at the international and national level. After many years of compartmentalisation of maritime domains, policymakers have left behind traditional governance frameworks by developing national integrated maritime policies (IMPs) for the sustainable use of oceans and seas [5]. Between the 1990s and the turn of the century, a number of major maritime nations (among them Australia, Brazil, USA, Norway, and Japan) launched national IMPs [6]. These policy initiatives predated the European Union's IMP which was adopted in 2007. IMPs typically provide a comprehensive governance framework to support both the sustainable use of seas and oceans while ensuring a horizon of prosperity for the population of the surrounding coastal regions by building on the blue economy [7]. Thus, IMPs typically aim to foster the sustainable development of all sea-based activities and coastal regions by improving the coordination of policies affecting the oceans, seas, islands, coastal regions, and maritime sectors, and by developing cross-cutting tools. These IMPs need to consider a wide range of issues in a complex and challenging environment where multiple stakeholders interact. This paper focuses on sustainable sea governance in the context of cross-cutting sectoral policy integration through IMP development and implementation. Such policy integration can prove to be very difficult as policy areas often operate in isolation from each other according to their own dogmas, values, and traditions. The legal system may support this sectoral division because the regulations, entrusted to a variety of ministries and agencies, guide joint action by following a sector-by-sector approach [8]. Therefore, moving towards greater policy integration involves not only changes within the institutional organisation but above all changes in the values, norms, procedures, and objectives that underpin operational decision-making [9].
The central research question of this paper is as follows: how can sustainable sea governance, specifically IMP governance, be arranged to support more effective policy integration? Effective policy integration concerns the effective management of cross-cutting issues in policy-making that transcend the boundaries of established policy fields [10]. Policy integration results in one joint policy for the sectors involved. The potential benefits of policy integration include helping to convey the big picture for strategic issues, realising synergies and maximising policy effectiveness, exploiting economies of scale, providing a framework for resolving potential conflicts and making trade-offs, and improving service delivery [11].
To answer the research question, the paper identifies and discusses a few key strategic and institutional issues which are expected to promote more effective policy integration in IMP development and implementation. First, we analyse the formulation of vision statements in IMPs in terms of how these incorporate economic, social, environmental, and institutional considerations and how stakeholders are involved in the formulation process. Second, we introduce a novel conceptual framework on stakeholder participation and management in IMP development which aims to overcome the limitations of the widely used bottom-up and top-down approaches in policy formulation. Third, we analyse the extent to which IMPs show regional embeddedness by addressing specific location-bound geographical, political, economic, and social dimensions. Finally, we study the governance changes under the dual lens of time frame and institutional plasticity [12].
The presented research outcomes provide guidance to policymakers and stakeholders on key strategic and institutional considerations that should enhance effective policy integration during the formulation and implementation of a national IMP. While the paper is primarily concerned with recommendations to support more effective policy integration, it also contains some empirical analysis of existing IMPs to support and illustrate some of the policy notions and recommendations. The purpose of referring to the empirical cases is thus illustrative in nature.

Vision Statement Analysis
IMPs are developed in an environment where many, sometimes competing, political initiatives co-exist. Traditional governance frameworks, characterised by a plethora of agencies, each accountable for a well-identified sector, challenge and potentially undermine cross-cutting policy initiatives. Therefore, effective policy integration demands that policymakers collectively focus on commonly agreed key principles as a first step towards the integration of an incoherent set of policy areas [13]. Such an integration exercise should be founded on a vision statement which is a written conceptualisation and formalisation of a shared and desired future. A unifying conception allows to bring together a formerly disparate set of elements in an integrated policy [14]. The expectations of each of the involved stakeholders should be formally stated during the formulation process of a vision statement, otherwise the further viability of the integration project may be seriously hampered. Vision statements help to rationalise existing goals and constitute the 'architecture' of any new integrated policy [15]. These statements are important in the development of an integrated maritime management plan because they have a function that aims to give substance and guidance to the rationale [16].
The notion of vision statements firstly emerged in the scholarly literature of corporate management (see [17][18][19][20]; for an overview, see [21]). The concept spread to other spheres, including into the public policy domain where it is now widely used. The relevant attributes of a vision statement in the business context differ from the characteristics in a public policy environment, even though the concepts of Corporate Social Responsibility (CSR) and benefit corporation somewhat bring the two backgrounds closer together. Vision statements of corporations typically refer to future value propositions, sources of profitability, and comparative advantages in an increasingly competitive environment. Policy (supported) visions usually have a stronger orientation on justice and ethical considerations and should guarantee fair treatment between citizens and transparency in the decision-making processes. Policy (supported) visions are developed in a network environment wherein cognitive influence games (rather than competition) play a more primordial role [22]. The priority for policymakers is then to establish a common framework which eases the appropriation and the assimilation of every individual.
It would be wrong to analyse vision statements, which guide strategy, under the sole lens of the aspirational dynamic that they instil. The quality of a vision statement must also be measurable. Therefore, the next sections analyse the semantic quality of vision statements in existing IMPs by focusing on the triple bottom line. Furthermore, we present recommendations on why and how to include stakeholders in the formulation of this envisioned future and how to effectively communicate on the contributions of their involvement afterwards.

Triple Bottom Line Considerations
Sustainable policies should concomitantly address social, environmental, and economic issues because these triple bottom line considerations cut simultaneously into almost every conceivable sector [23]. In the context of IMPs, vision statements should also provide a policy dimension with regulation of conflicting activities. Thus, the semantic arrangements in vision statements should not only encapsulate and reflect social, environmental, and economic aspects but also institutional ones. Appendix A, Figure A1 presents the vision statements of 10 national IMPs to illustrate the diversity in semantic content, scope, and overall reach. Colour codes are used to identify conjunctures of social, economic, environmental, and institutional interests in existing vision statements. For example, the vision statement in the IMP of Ireland reads as follows: "Our ocean wealth will be a key element of our economy recovery and sustainable growth, generating benefits for all our citizens, supported by a coherent policy, planning and regulation, and managed in an integrated manner". Terms such as "wealth", "recovery", and "growth" refer to the economic aspect. The "sustainable" adjective indicates that the desired economic growth should be respectful of the environment and social aspects. The expression "generating benefits for all our citizens" is an illustration of the political will to pay attention to intergenerational equity among all social classes. Thus, Ireland's IMP explicitly considers the social sphere of the triple bottom line. The last part of the vision statement, namely "supported by a coherent policy, planning and regulation, and managed in an integrated manner", is connected to the institutional (policy) dimension. Being both political and policy documents, IMPs may also use vision statements as catalysts for their own national ambitions. This tendency is found in many integrated policies; e.g., the Bahamas wishes to "globally position the archipelago as an economic force", Colombia expresses a desire to "turn Colombia into a Medium Oceanic Power", Japan wishes to "to realise a new oceanic state", and the Netherlands mentions "an international leading maritime position".
Policymakers should pay careful attention to the formulation of vision statements as they provide strong guidance towards the integration of fragmented policies within the national sphere and present a powerful communication tool to the international scene. Still, a vision statement remains a rather hollow catch-all phrase if it is not supported by concrete integrated policy measures and plans in the IMP aimed at achieving clear social, environmental, economic, and institutional goals.

Stakeholder Involvement in the Formulation Process
Stakeholder participation in the formulation of a vision statement influences its further endorsement. Relevant stakeholders in a national IMP context might include internal stakeholders of public policy departments and ministries at national level and external stakeholders such as public organisations at other geographical scales (regional, local, and where applicable, supranational), industry associations and representatives, community and environmental groups, the general public, non-governmental organisations (NGOs), and anybody who might be concerned or has an interest in the development of a given sea region. Vision statements help to increase the comprehensiveness and inclusiveness of an IMP among the different stakeholders. A lack of stakeholder involvement in the formulation of the vision statement presents the risk that the purpose behind the policymaking will not easily be grasped by all relevant sectors. Policymakers typically consult various stakeholders in the process towards vision statement formulation in an IMP context. In some cases (such as in the Netherlands, Germany, and Nordic countries), the modalities of stakeholder participation including the associated timelines and transparency requirements are laid down in wider legal frameworks on public policy and project management procedures. As an illustration, the Guide to Consultation in Statute Drafting issued by the Finnish Government [24] defines policies for the consultation of stakeholders and their participation in the law drafting process.
Still, most integrated policy documents do not explicitly report on the actual processes and timelines that were used to ensure stakeholder involvement in the development of their visions. By failing to provide written evidence on the careful consideration of stakeholder's views, policymakers reduce the overall transparency of the policy integration process. Such transparency is desirable as it makes apparent how various interests played out during the formulation process and which aspects were known by and explained to stakeholders. We agree with Forssbaeck and Oxelheim [25] over the fact that transparency is not limited to the simple disclosure of information, but also has a strong demand-side dimension. Information must be accessible and reliable and have a significant value for stakeholders. IMP documents frequently fail to fulfil this requirement. This condition is even more important if the information, which must be transparently disclosed to stakeholders, is the direct outcome of stakeholder participation in the process. Stakeholders are not only the end-users of IMPs, but they should also (to a certain extent) participate in the process as (co-)designers. Summing up, IMPs would gain in visibility and transparency if policymakers communicate more about the processes of stakeholder involvement in the formulation of vision statements. Policymakers should clearly state the elements that emerged from the consultation process by making a distinction between the ideas that were withheld and those that were considered but not included in the eventual formulation. It is important to adequately address stakeholders' expectations in the policy-making process and to communicate on the reasons behind decisions in a lean and purposeful way.
In summary, researchers widely support the establishment of a common vision that will define the desired future for the seas and oceans and go beyond individual expectations [26]. The formulation of a vision statement with stakeholder involvement may generate a tremendous mobilising momentum that facilitates the transition to more effective policy integration [27]. A common vision may help to solve the problem encountered with so-called actor systems, namely the fact that each actor develops its own perception of the problem. We note, however, that vision statement formulation is a necessary but not sufficient aspect of effective stakeholder management. Still, policymakers are advised to define a common vision in order to bring together the often-contradictory objectives which usually emerge in a multi-sectoral and multi-actor environment [28].

Stakeholder Management Processes and Organisational Ambidexterity of Institutions
The combination of bottom-up and top-down approaches constitutes a long-standing challenge in applied policy analysis [29].
Scholars traditionally make a distinction between an approach that comes from the interactions between social participants and their surrounding environment (bottom-up) and a legalistic approach of public action characterised by central planning and state intervention (top-down) [30]. One of the key dilemmas faced by policy makers when striving for effective policy integration through an IMP is how to reconcile the desire for autonomy (bottom-up) with the accountability requirements (top-down). In a multi-factor maritime environment, it is suboptimal to separate top-down and bottom-up flows into different entities. We conceptualise a reconciliation of the two approaches by proposing a new method for stakeholder involvement in IMP development and implementation described as vision-down plans-up. Such an approach should support a more effective policy integration, reduce the risk of conflict, and enhance the conciliation process between different maritime uses.
Integration changes cannot be solely imposed following a top-down perspective. Indeed, effective policy integration will not thrive without the support, vision, and involvement of stakeholders. Conversely, if policymakers only follow a bottom-up approach, the whole exercise might lose focus and suffer from a lack of leadership and guidance. Misjudgements over who should participate in the process and how they should participate might undermine the focus of the policy integration path. Policymakers should not give the same weight inside the process to every single stakeholder. Policymakers must be aware that the weight of a stakeholder is often determined by the (over-powerful) voice a stakeholder has. Powerful individuals representing an organisation may often infiltrate the whole process with the consequence that more silent and less assertive organisations might be kept out. In order to avoid this cognitive bias, policymakers should carry out a stakeholder analysis to differentiate and classify stakeholders based on their (desired) involvement in and potential impact on both the IMP development process and associated decision-making.
The main issue is to bring the top-down focus to a point where it meets the bottom-up endorsement. The vision-down plans-up approach makes it possible to combine the best of both worlds. We argue that this approach may increase the organisational ambidexterity of maritime governance. Organisational ambidexterity is defined as the ability to reconcile the exploitation of existing resources and skills with the exploration of new ones [31]. Ambidexterity in a maritime context involves rethinking the organisation of maritime governance both in contextual and structural terms. The vision-down approach is part of the contextual ambidexterity because it is acknowledged that the proposal of new vision paths and practices should be the result of interactions with relevant stakeholders. Conversely, the plans-up approach is part of the structural ambidexterity because it suggests that planning decisions should be coordinated at the highest political level by providing clear objectives, priorities, and guidelines to the sectoral stakeholders. Although it is commonly recognised that there is no unique miracle model capable of giving a satisfactory answer to manage social interaction issues, the proposed vision-down plans-up approach allows stakeholders to know what end objectives and vision need to be pursued.

Tension between Policy Convergence and Regional Embeddedness
Policy convergence is a salient aspect in the comparative study of public policies [32]. Strong empirical foundations can be found on the issue of policy convergence. Still, we argue that a dichotomous approach of considering the development of new public policies only through the dual lens of convergence or divergence is not stricto sensu supported in the context of IMPs. To support our view, we conceptualise and exemplify the phenomenon of regional embeddedness which plays an important role in adapting IMPs into a specific national or regional context. We will demonstrate that observed tendencies towards policy convergence do not exclude strong levels of regional embeddedness in IMPs and vice versa.

Policy Convergence
The push for more integration of maritime policies is supported by international governmental bodies, instruments, and conventions. These kinds of international policy diffusion processes inevitably lead to policy convergence or even some level of standardisation in policy formulation. The process of policy diffusion may lead to similarities in the legal provisions of different national IMPs. If they accumulate, these common provisions may result in policy convergence at the IMP level. The temptation to formulate similar, or even identical, maritime strategies is a common trend observed when national jurisdictions want to move towards more integration.
Policy convergence can manifest itself in different ways, such as at the level of the discussed themes or building blocks, identified challenges, strategic goals, and ambitions and strategic actions and implementation plans. The building blocks methodology [33] is used here to provide a holistic and broad analysis of the contents of over 40 existing IMPs and related maritime policy documents from around the world. This analysis reveals that most IMPs share a common set of building blocks in the common maritime systems across the different integrated policies (Figure 1). Such a holistic analysis shows that a vast majority of IMPs intend to create a 'maritime system' as suggested by the double arrow. The 'maritime system' is completed and unified towards a common purpose and objectives as distinct from a sectoral policy. The building blocks approach demonstrates that IMPs are coherent because these national policies mutually reinforce each other in the pursuit of their own policy objectives. Nevertheless, (inter)national policy coherence is not synonymous with consensus. Normative differences may account for cross-national variation between national IMPs, resulting in certain levels of regional embeddedness in policy formulation.

Regional Embeddedness
New theoretical frameworks have emerged in recent literature that support a holistic and locally situated (context sensitive) approach to decision-making [34]. IMPs are geographically, politically, economically, and socially embedded in their local/regional context. We identified four categories of regional embeddedness, i.e., geographic, political, economic, and social. These categories are not by nature hermetic and isolated from each other. On the contrary, they have holistic characteristics.
The development of an IMP is a path-dependent process which is strongly influenced by the society and the surrounding environment. Once a relevant policy framework is developed somewhere, the fundamentals of these new policy ideas will spread globally. These ideas will reach national policymakers in their raw form (policy diffusion). Afterwards, national policymakers must shape these ideas in a unique way so that they can be stretched and adapted to the prevailing national practice in force (embeddedness). In that case, policymakers operate according to a logic of appropriateness, not a logic of consequentiality [35]. In other words, policy convergence does not and should not exclude regional embeddedness.
We illustrate the role of regional embeddedness in IMP development and implementation by demonstrating how the concepts of hard and soft sustainability resonate through the presented sub-categories of regional embeddedness. The balance in Figure 2 refers to the fact that each IMP presents a different mix of hard sustainability and soft sustainability aspects. Even if IMPs can often be seen as patchwork policy documents that combine and articulate the notions of hard and soft sustainability together, a distinction can theoretically be made between these two notions [36]. At the core of this distinction, there is the acknowledgement that the overall capital stock (OCS) is the aggregated sum of individual forms of capital, namely natural (N), man-made (M), and human (H). The notion of soft sustainability allows compensatory trade-offs between the different forms of capital as long as the OCS increases. On the other hand, the notion of hard sustainability includes two requirements. Firstly, it is no longer permitted to substitute one form of capital by another. Moreover, the prerequisite that the OCS is growing (or is at least constant) is supplemented by the condition that the relevant specific form of capital cannot decline [37].

Empirical Evidence of Regional Embeddedness in a Soft Sustainability Context
Some aspects of national IMPs include soft sustainability considerations. Regarding geographical embeddedness, most important is the emergence of countries as strong and powerful logistics hubs, essentially because they are geographically positioned at the centre of a maritime trade network. As an illustration, the Maritime and Port Authority (MPA) of Singapore envisions to develop and promote Singapore as a premier global hub port and an international maritime centre. It appears that in a very pragmatic way, these hubs prefer to follow a soft sustainability approach rather than a hard one. Even if there is an underlying trend which, as observed by Shi et al. [38], tends to upgrade port-originated maritime clusters into maritime clusters that feature ecologically friendly ports, a maritime logistics hub remains a nodal point creating and facilitating value-added services [39] rather than a concentrated platform which could mitigate externalities through economies of scale.
Regarding political embeddedness, the possible membership to supranational organisations may influence the choice of national decision-makers as to whether to favour hard or soft sustainability. In fact, the EU IMP can be interpreted as being based on soft sustainability. Indeed, the European IMP categorises ecosystem conservation as an ordinary sectoral use [40]. Given that blue growth is recognised as the priority objective, the EU IMP refuses to arbitrate between two exclusive maritime activities and promotes the concept of integrated use [41]. In that context, the EU IMP will allow Member States to strike a balance between protecting the marine ecosystems and maximising the use of its resources as a source of economic growth. The EU IMP approach cascades into national IMPs of EU members, although with different intensities, interpretations, and regional touches among these states. EU membership can also shape aspects of the adopted governance structure on IMPs. Ireland, for example, has instituted in its integrated maritime governance structures the role of an Attaché to the European Commission. In doing so, Ireland exemplifies the phenomenon of political embeddedness and illustrates how being a Member State of a supra-national organisation may modify its own national structures.
Regarding economic embeddedness, some countries want to maintain their national competitive advantage and refute the paradigm shift that would consist in selling off their competitiveness in favour of a more sustainable and inclusive economy. For example, the German Federal Government has a strong interest in securing and strengthening the competitiveness of its maritime industry due to its importance for the entire German economy, the high level of innovation, and its strategic role [42]. Developing countries insist that soft sustainability is the best (or least bad) option available to them to support their (socio)-economic deployment and recovery, arguing that a harsher approach would hamper their trajectory towards their full economic capacity. As an illustration, Colombia is seeking to find a "balance between economic development and sustainability" while the Bahamas lays claim to its "right to development".

Empirical Evidence of Regional Embeddedness in a Hard Sustainability Context
Other aspects of national IMPs refer to the concept of hard sustainability. Although Merrie and Olsson [43] point out that the emphasis on Ecosystem-Based Management (EBM) has diluted over time, most IMPs that follow a hard sustainability approach refer to the concepts of Ecosystem-Based Management (EBM), Good Environmental Status (GES), and precautionary approach.
Geographical embeddedness is related to the geographical diversity of countries. Countries which are more exposed to the consequences of climate change, such as archipelagos, tend to embrace the concepts of EBM and GES.
Regarding political embeddedness, Raakjaer et al. [7] shows that a fall back on EBM is an argument to push for more regionalisation of marine governance structures. Indeed, the regional scale seems to best match sub-ecosystems boundaries. Van Hoof et al. [44] recognise that EBM is a catalyst for regionalisation but add that EBM also provides a rationale for integration processes in the sense that sectors need to be harmonised across the regional marine sub-ecosystems. Thus, implementing EBM at a regional sea level presupposes a parallel process of both regionalisation and integration of marine governance structures.
Regarding social embeddedness, Saunders et al. [45] argue that hard sustainability is concerned with the careful preservation of resources for future generations. Intergenerational equity is not emphasised in the soft sustainability approach which states that future generations will not suffer from environmental losses as long as wealth creation compensates for these damages [46]. Vision statements of several national IMPs contain provisions that directly refer to intergenerational equity (see earlier). A variety of synonymous concepts can be found in the vision statements, such as "for the benefit of all, now and in the future" or "for the benefit of the current and future generations". The consideration of indigenous populations in the development of IMPs such as in Canada and in Australia [47] may push national authorities to move towards the concept of hard sustainability. These local communities attach great importance to the conservation of their environment and its natural resources. While Bennett et al. [48] argue that coastal and indigenous communities need to be included in all decision-making and policy processes, Kerr et al. [49] refer to a dynamic tension between an economic blue growth agenda (soft sustainability) and sociopolitical rationales which seek to repair historic inequities by making sure that indigenous communities benefit from fair access to natural resources.
The above discussion and empirical illustrations indicate that national policymakers show levels of regional embeddedness in IMPs. Thus, they combine inevitable policy similarities with the consideration of specific national and regional specific interests. The combination of the four interacting forms of embeddedness (i.e., geographic, political, economic, and social) points to the transversal dynamics by recognising the modulated and not dyadic nature of policy integration processes [50]. Therefore, analysts and decisionmakers are recommended to pay more careful attention to all sources of embeddedness when dealing with the tension between policy diffusion and policy convergence.

Time Frame and Institutional Plasticity
Institutions, along with their strategy and vision, might need to be reshaped to establish effective policy integration [51]. Institutions may affect the integration of crosscutting initiatives and vice versa. Institutional change unfolds within a specific time frame and might occur abruptly or gradually. We firstly discuss the importance of a relevant time frame when dealing with governance challenges in an IMP context. Next, we explain how governance changes can be integrated into the institutional domain by mobilising the concept of institutional plasticity.
Institutional changes should be placed into a time perspective. The appropriate time frame for launching an IMP is at the conjunction of two developments. First, there must be a policy window opportunity. The combination of the discovery of a viable answer to solve an identified problem and the political will to provide this answer is known as a policy window momentum [52]. Second, the adoption of an IMP should be preceded by a social learning trajectory. According to Hall [53], social learning processes are at the core of policy changes introduced by policymakers. For example, the EU IMP has built further upon past experiences of pioneering countries such as Canada. The comparative work of Koivurova [54] clearly shows that elements of the Canadian experience have benefited the EU. Our previous section on the four forms of regional embeddedness demonstrates that the iterative development of IMPs should be understood above all as the result of cognitive processes embedded in their local context [55].
The institutional domain is subjected to shocks induced by regular changes in practices. The concept of institutional plasticity recognises that a well-constructed institutional domain can cope with these changes without necessarily modifying its structures [56]. Processes of institutional plasticity allow changes to an institutional system without necessarily breaking out of the existing path. Streeck et al. [57] suggest that the process of institutional change is characterised by a succession of minor modifications to existing practices supported by mechanisms of mutual adjustment between actors. The concepts of conversion, layering, stretching, and recombination are the most known forms of institutional changes [58]. Layering takes place by gradually adding new rules or procedures to existing institutions or by adding new functions or mandates to existing institutional arrangements. Each new layer constitutes only a small change, but the cumulative process of layering can lead to a major institutional transformation. Conversion is the alteration of existing institutions to serve new purposes or functions. Stretching and recombination occur when actors cannot change existing arrangements but try to initiate changes by creatively interpreting and combining these existing rules and procedures. These practices lead to institutional plasticity in existing policies without breaking out of the existing path (i.e., avoiding path disruption).
As an illustration, we argue that the EU IMP has been characterised by a gradual layering and (re)combination of several different strategic documents and tools, without radically disrupting past policy paths. Suárez de Vivero and Mateos [59] referred to the complexity emerging from the attempts to incorporate a large array of (past) sector-based policy reports, insights, and political positions (see Appendix B, Figure A2). Such a process of institutional plasticity might run the risk of losing focus and dragging some 'policy ballast' of the past. The term policy ballast refers to ineffective policy elements that have been introduced and institutionalized in the past and might influence new policy initiatives through processes of path dependence. However, as it is the result of an organic process grounded on the adaptation and integration of past (positive) policy experiences, such an approach reduces the risk of highly disruptive impacts and associated opposition in policy circles. Still, the analysis of layering mechanisms at work cannot be solely explained as an unintended consequence arising from the intrinsic complex character of institutional structures at national or supranational level (such as the EU). We argue that the responsibility of policymakers cannot be diluted. On the contrary, it appears that policymakers knowingly use layering mechanisms as part of a cognitive process. Indeed, layering processes allow policymakers to communicate about a new overarching policy only on form rather than on substance. However, by over-using this process, policymakers are confronted with the institutional sprawl that they created themselves. Heredia [60] states the following: "the evolution of IMP is characterised by the proliferation of texts and instruments with a very diverse scope, but in general suffering from an obvious lack of legal density". Faced with this challenge, decision-makers, for whom a real paradigm shift may require too many resources, prefer to layer again to realize more coherence. The sprawl system is then subjected to a perpetual and iterative regeneration.
The institutional plasticity concept recognises the progressivity both in the time factor of institutional changes as well as in the absorption of these changes into the institutional domain. The absorption of the integration imperatives is often characterised by the layering of new elements to already existing policies or the conversion of old structures to best embrace new policy objectives [61]. If these processes are not carried out diligently, it may happen that competences are allocated in a vague way and are inconsistently fragmented between the different actors. Stakeholders are then faced with a certain degree of institutional ambiguity in policy integration [62]. The importance of developing adequate governance structures is the subject of our next section.

Empirical Evidence on the Role of Effective Governance Structure in an IMP Context
Bringing together disjointed and fragmented agreements within a coherent architecture for the governance of maritime affairs remains a major challenge [33]. Indeed, governance often is the main inhibiting factor which can explain the failure (or at least the very relative degree) of effective policy integration [63]. Moving towards policy integration in an IMP context is only conceivable if policymakers design efficient governance systems. Providing a consistent and well-constructed governance framework for cross-sectoral reforms is a policy task assumed by various countries which seek to strengthen their institutional building capacities [64]. To illustrate the role of governance attributes in IMP development, we zoom in on two countries. First, we study the institutional arrangements developed in the Canadian IMP. Next, we comment on the debates which animated the French authorities over the most relevant way to integrate this holistic paradigm shift into their governmental institutions.

Canada
Canada is one of the earliest adopters of policy integration in an IMP context. The previously mentioned notions of regional embeddedness, institutional plasticity, and social learning are well-found in the governance framework adopted in Canada.
Regarding geographical embeddedness, Koivurova [54] remarks that the management scheme in Canada is characterised by its flexibility. The general objective is to establish Integrated Management plans for all marine areas in the country. Still, the management structures are tailored to best suit the specific conditions in each territory. Moreover, the consideration for the indigenous population (social embeddedness) is well-found in the organisation of the governance structure. In fact, the Canadian legislator established a direct communication channel between the Aboriginal representatives and the Integrated Management Body (Figure 3). Concerning institutional plasticity, we note that in the Policy and Operational Framework for Integrated Management pursuant to the Canadian Oceans Act, it is clearly mentioned that "the institutional structures put in place to govern the coastal, estuarine, and marine waters will evolve in keeping with the intensity of ocean use activities and the interest and the capacity of participants".
Finally, regarding the social learning phenomenon, the Canadian government hopes that as the Integrated Management process and plan mature, incremental achievements will demonstrate the value of the process and spur others to become more involved.

France
The French authorities wondered about the following question: "Should we bring together the maximum number of services dealing with the sea under the sole authority of the Minister responsible for the sea or should we prefer the emergence of a strong inter-ministerial coordination?" [65]. To settle this question, the French authorities used a strategic scenario tool (Figure 4) to build a coherent strategy and anticipate changes. Such a strategy consists of allocating human, financial, physical, and even technological resources. Scenario building is a frequently used method to reduce uncertainty and allocate resources in an informed manner, especially when the environment is complex and uncertain. Scenarios help to understand the level of uncertainty and risk as well as distinguish between mutually exclusive policy options. Policymakers use scenario planning to visualise the perception of political forces as well as the comprehension of institutional constraints and to assess the robustness of envisioned policy alternatives. The bold arrows between the different scenarios depicted in Figure 4 show the potential weaknesses of each scenario and how these weaknesses can be dealt with when opting for another scenario. Under the first scenario, the French Authorities intend to create a large central administration department, namely the Directorate-General for Sea (DGMer) overarching the previously disordered plethora of agencies. Centralising the maximum number of services and competences within a single department is not without pitfalls. The more policymakers make excessive efforts to increase the consistency among institutional domains, the less flexibility fuels into the decision-making system because an inefficient degree of central control is introduced [66]. In fact, decentralisation and institutional diversity are salient theories in contemporary academic research because these approaches appear to be more adapted to tackle complex challenges [67]. The adoption of discretionary tools by each sub-unit that enable more tailored responses is a key characteristic of polycentric governance systems wherein each sub-unit enjoys a considerable degree of independence [68]. Although we agree with Djalante et al. [69] over the greater resilience potential of a polycentric system in comparison to one that is highly centralised, we add that the potential for resilience is strongly influenced by the considerations brought to local specificities. Whereas we acknowledge that it is easier to perform such a task in a polycentric framework [70], we argue that shaping governance through our previously developed lens of regional embeddedness will allow policymakers to increase the resilience of their governance framework.
The second scenario assumes the establishment of a coordination management body (état-major de coordination). This scenario seeks to federate the various sea-related public administrations together but without necessarily merging them into a completely new structure. Therefore, this scenario relies to some degree on the mechanisms of institutional plasticity by proposing an organic evolution of the existing governance settings without choosing a new system which clearly deviates from the current one. However, we note that the coordination management body must have sufficient weight to be able to structure the dialogue in a strategy-making process without being subjected to a discussion led by highly sectoral and vested interests [71]. The adoption of the second scenario may constrain the coordination management body to only mundane or daily policy making stages [72]. Therefore, policymakers need to include integration instruments also at a higher strategic level (see scenario 3).
It would be wrong to state that a polycentric system excludes any leadership consideration. The main issue is rather to know who exercises leadership. The third scenario provides the necessary leadership to the Secretariat-General for Sea (SGMer). This policy option is based on a high-level impetus because the SGMer (which ensures the coordination function on behalf of the minister responsible for the sea) remains a service attached to the Prime Minister's office. In that case, this scenario is consistent with the European Commission guidelines on IMP. These guidelines state that the internal coordinating structure should include a mechanism providing political guidance at the highest level and responsibility to act as a political leader and as a catalyst for the integrated approach at the political level [73].
As a conclusion, we recommend policymakers to combine a polycentric governance system together with providing a high-level impetus. We acknowledge this is a fragile equilibrium to achieve because this combination is at the core of the tension between accountability and autonomy. Finally, the trade-off between accountability and autonomy is sometimes caricatured into a dichotomy of principles which consists either in favouring the bottom-up approach or the top-down approach. The need to overcome this cleavage was analysed earlier when proposing a vision-down plans-up approach.

Conclusions
Integrated maritime policies (IMPs) provide a comprehensive governance framework to support the sustainable use of seas and oceans while ensuring a horizon of prosperity for the population of the surrounding coastal regions. This paper contributes to academic and policy discussions on strategic and institutional attributes of sustainable sea governance. This research presents a conceptualisation of mechanisms and approaches that should facilitate policymakers in designing and implementing effective, sound, and inclusive processes towards policy integration in an IMP development and implementation context. First, the presented research provides guidance on the importance and formulation of vision statements in effective policy integration during IMP development and implementation. Semantic arrangements in vision statements should not only encapsulate and reflect social, environmental, and economic aspects, but also institutional ones.
Second, this research contributes to the growing maritime policy literature on stakeholder management by (1) demonstrating that IMPs would gain in visibility and transparency if policymakers communicate more extensively about the processes of stakeholder involvement in the formulation of vision statements; and (2) conceptualising a vision-down plans-up approach which helps to streamline stakeholder involvement and increases the organisational ambidexterity of maritime governance.
Third, we show that IMP development cannot be assessed through the dual lens of convergence or divergence. The process of policy diffusion does not always lead to isomorphism or homogenisation. Forces towards regional embeddedness at geographical, economic, political, and social levels play an important role in adapting IMPs into a specific national context. Therefore, observed tendencies towards policy convergence do not and should not exclude strong levels of regional embeddedness in IMPs and vice versa. Policymakers should clearly articulate and motivate regional embeddedness attributes while realizing policy integration in a national IMP in a multi-stakeholder environment. Moving integrated maritime policies further away from the concept of regional embeddedness would increase the amount of absolute policy bias.
Fourth, effective policy integration in an IMP context requires the design of efficient governance systems. In this paper, we particularly focused on the relevant time frame and policy window momentum, social learning trajectories, and the role of institutional plasticity in governance changes. While mechanisms of institutional plasticity can help to avoid highly disruptive impacts of policy changes and associated opposition in policy circles, they can result in a less ambitious and poorly focused IMP development which suffers from institutional sprawl and the dragging of past 'policy ballast'.
The conceptual insights presented in this paper have been illustrated by some empirical examples of national and supranational IMPs. The purpose of referring to the empirical cases is thus illustrative in nature. Further research can focus on a more extensive empirical validation of the presented insights by developing in-depth case studies of specific national IMPs or by providing a comparative analysis of such integrated maritime policies.

Conflicts of Interest:
The authors declare no conflict of interest.