Research

INTRODUCTION

Estuary regions are some of the most contested spaces on the planet. The continuous interaction between sea, river, and land creates highly dynamic environments that support a diverse and endemic range of flora and fauna (Lonsdale et al. 2022), contain high levels of biodiversity (Paalvast and van der Velde 2014), and play an immeasurable role in nutrient cycling and climate regulation (Martinetto et al. 2020). In the coming decades, these coastal and transitional ecosystems will be increasingly exposed to environmental change, primarily due to intensifying industrialization, urban development, and the expansion of agriculture, aquaculture, and climate change (Elliott et al. 2019, Intergovernmental Panel on Climate Change (IPCC) 2019).

Their appeal for various human activities and resulting pressures give rise to a multitude of conflicts in these highly dynamic environments (Fidélis et al. 2019). Conflicts among estuarine actors and stakeholders arise due to competing uses, such as shipping, coastal protection, renewable energy development (e.g., wind power or ground-mounted photovoltaics), agriculture, housing, ecosystem preservation, and recreation needs. The interconnections among these sectors characterize estuaries not only as purely natural or economic spaces, but also as cultural landscapes and places (Barrett et al. 2021). Thus, estuary regions are shaped by natural, social, economic, cultural, and historical developments. Their multifaceted but yet not systematized character results in a lack of estuary governance approaches, making it challenging to manage them effectively.

Scholars have recently begun to engage with estuary governance arrangements and interventions in order to improve conflict resolution and environmental conditions (Dawson et al. 2011). Perspectives and concepts range from addressing the relations between human and non-human entities (Truchet et al. 2022), by applying integrative ecosystem management services (Sousa and Alves 2020), to future-oriented climate change adaptation planning (van der Voorn et al. 2017). All these approaches converge in the fact that they call for an implementation of governance arrangements at multiple levels while demanding a serious and active actor or stakeholder engagement (e.g., Boyes and Elliott 2015, Lonsdale et al. 2015).

Establishing appropriate governance arrangements in estuary regions is, however, difficult (Dawson et al. 2011, Daniell et al. 2020) as their fragmentation and segmentation results in and is the product of a lack of comprehensive estuary governance. Structurally seen, estuary governance is conceived as being characterized by multiple administrative boundaries and bodies dealing with the sea, rivers, and land at the same time and in the same place. This results in a multi-layered puzzle of legal and institutional boundary conditions consisting of multiple authorities with overlapping jurisdictions and distinct powers, responsibilities, laws, and management tools (Carvalho and Fidélis 2013). Fuzziness or so-called governance “silos” emerge in this context, with their sea-, river-, and land-related parts managed separately by limited politico-administrative institutions.

Historically seen, estuary governance has been a subject of study since the 1980s (Hennessey and Robadue 1987, Imperial et al. 1993) and witnessed growing awareness and uptake among scholars in the areas of public administration and management and the environmental sciences since 2010. Here, a notable terminological and conceptual ambiguity evolved that characterizes the field until today. Furthermore, it has also been recognized that the field could conceptually and practically benefit from collaborative governance (Dorcey 2004) while its systematic application and conceptual advancement in estuarine contexts remains limited. Besides these limitations, collaborative governance still represents a prominent approach to policy making that aims to be more innovative, transparent, flexible, need-oriented, and socially inclusive than earlier and more conventional approaches (Gash 2022). Existing collaborative frameworks thus tend to subsume environmental and conflict dimensions under a broader system context, which, as our review will demonstrate, does not adequately reflect their central role in estuary governance. Furthermore and going beyond its normative aspirations, collaborative governance also holds an analytical potential as it examines the structures, processes, and outcomes of cooperative arrangements, reflecting both a narrow focus on institutionalized collaboration and a broader understanding of governance as multi-stakeholder interaction. It is defined as “the processes and structures of public policy decision making and management that engage people constructively across [...] spheres to carry out a public purpose that could not otherwise be accomplished” (Emerson et al. 2012:3).

Against this background, we propose that exploring the potential of collaborative modes of governance may provide valuable perspectives for addressing the persistent governance challenges of estuary regions, particularly by enhancing conflict negotiation, supporting system adaptation, and strengthening responses to environmental change. However, the general question of how this topic should conceptually be developed remains unresolved (Scott 2015). To engage with this question, this article elaborates and compares both the concept of estuary governance and the concept of collaborative governance (Ansell and Gash 2008, Emerson et al. 2012, Emerson and Nabatchi 2015a). We systematically analyze the existing literature on estuary governance with a focus on its concepts, thematic strands, and trends. Current scientific discourse is summarized and provides a conceptual overview of the current state of the art that results in a meta-synthesis that uses these findings, develops thematic clusters, and integrates them into the concept of collaborative governance. The aim consists in sketching out a conceptual framework for “collaborative estuary governance.”

This endeavor appears to be beneficial for two reasons: (1) research on collaborative estuary governance holds the potential to contribute new perspectives to estuary governance and (2), with the anticipated impacts of global and climate change, our framework can help to re-focus the to-date neglected separated “environmental” and “conflict” dimensions within collaborative governance (e.g., Ansell and Gash 2008, Emerson et al. 2012, Emerson and Nabatchi 2015a).

The article is structured as follows: we first report on the methodological approach of our systematic literature review of estuary governance. Here, emphasis is put on the concepts, themes, and trends to unpack the structuring notions of estuary governance and bring greater clarity to the field. Second, we develop a framework for collaborative estuary governance based on a literature meta-synthesis and discuss the resulting collaborative dimensions, aspects, and analytical foci for our framework to be developed. Third, we conclude by reflecting on the potentials and limitations of our framework for collaborative estuary governance.

METHODS

Although recent evidence indicates that collaborative governance holds the potential to resolve conflicts and support environmental development (Berardo et al. 2014, Newig et al. 2018), we would like to draw attention to the fact that it has not been applied to the concept of estuary regions. For this gap to be closed, a systematic literature review appears to be an appropriate way to reveal research needs to improve or develop conceptual frameworks. A meta-synthesis, an expansion of systematic synthesis findings across qualitative studies, aims to identify key metaphors, ideas, and concepts by generating consensus and new interpretations within a particular field to be integrated into an existing theory. It provides an interpretative approach for an evolving research field such as estuary governance (Jabareen 2009, Booth 2016) and contributes to reflection upon its conceptual structure, and the resulting implications and requirements for improvement.

Based on this approach, we conducted a systematic review to identify core characteristics of estuary governance studies to explore their intersections with collaborative governance. More specifically, the objective of our systematic literature review consisted in identifying and summarizing elements and applications of governance, the use of various theories, thematic clusters, and recent trends. Taking these elements to a meta-analytical level, we integrated the empirical findings into our conceptual framing of collaborative governance (Ansell and Gash 2008, Emerson et al. 2012, Emerson and Nabatchi 2015a).

A literature review following the widely established Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 Protocol (Page et al. 2021) was conducted. Given that the initial search by using the terms “estuar*” and “collaborative governance” revealed only seven articles, we decided to semantically broaden our search and split it into two search strings: search string 1 (“estuar*” AND “governance”) and to expand our literature exploration with search string 2 (“estuar*” AND “management”), (“estuar*” AND “sustainable development”), (“coastal” AND “collaborative governance”), and (“environmental conflict” AND “governance”). This progression of terminology was developed during an evaluation of the keywords, synonyms, and conceptually close and overlapping research fields, such coastal governance, of search string 1.

The search was limited to English-language peer-reviewed journal papers, including all results from “all years” for search string 1 and “2010” up to “November 2022” for search string 2. A total of 229 papers was included in the first search string and 1082 in the second. During a first screening of titles and abstracts, we excluded those articles that were not related to the notions of estuar* governance or nature science records. This resulted in a database of 148 in the first and 30 articles in the second search string. Then, the full text of each of the 178 relevant articles was analyzed. Here, inclusion/exclusion criteria were defined such as: (1) explicit topical link to the governance of estuaries, (2) reference to and uptake of social science perspectives (qualitative, quantitative, mixed methods). Finally, a total of 43 articles fulfilled the criteria developed and were deemed eligible for further inspection and examination. Figure 1 presents the systematic review flow diagram that synthesizes the literature search methodology.

During the examination of the articles, we inductively developed thematic clusters from three main categories: theoretical and conceptual approaches of estuary governance, spatial and thematic approaches, and trends of estuary governance. Within these main and sometimes intersecting categories, thematic clusters were formed, whereby all clusters were differentiated and newly developed. This procedure was carried out in feedback loops with the concept of collaborative governance to identify focal points and overlaps of the concept as found in the literature (Ansell and Gash 2008, Emerson et al. 2012, Emerson and Nabatchi 2015a). The procedure consisted of analyzing the intersections between literature and theory and ensuring the practical usefulness and applicability of the framework. Here, seven thematic clusters emerged: elements and applications of governance, application of theories, legal and institutional boundary conditions, understanding of space and place, scope of conflicts and challenges, climate change and future outlook, and stakeholder engagement.¹ These findings were conceptually inspected and then used to construct the framework with regard to the idea of a collaborative estuary governance while bearing in mind that all clusters were not mapped 1:1 to the framework, but rather used as a comprehensive, accurate, and credible grounding to develop the framework.

CHARACTERIZING RESEARCH ON ESTUARY GOVERNANCE

Despite the long-standing focus on estuary management in literature, estuary governance itself has received surprisingly little to almost no scholarly attention (with Fidélis 2019 as a positive exception). The earliest research using the term “estuary governance” was published in 1987 (Hennessey and Robadue 1987). However, since 2010, the number of publications has grown, but conceptual and theoretical dimensions and aspects in the debate on estuary governance remain underexplored. This is mirrored in our analysis, which reveals that the majority of studies on governance are driven by practical concerns, which makes it difficult to identify a well-established and theoretically defined field. This result clearly stands in contrast to other recently evolving governance fields emerging within social-ecological systems, where a more explicit and deeper engagement with and application of environmental governance theories can be found. For instance, in debates on coastal governance, Partelow et al. (2020) discuss different theories in the context of coastal systems. They examine the advantages and disadvantages of different environmental governance approaches, such as polycentric governance, network governance, multi-level governance, collective action, governmentality, adaptive governance, and evolutionary governance, and conclude that no consolidated theory has emerged. Instead, a variety of governance concepts have been applied and debated, and this diversity reflects the differentiated and context-dependent nature of coastal governance and highlights the potential for similarly nuanced approaches to be systematically explored and applied in estuary governance.

The review, moreover, shows that only a small number of the studies reviewed in this study use governance as a theoretical concept, and among them, some conceive estuary governance and multi-level governance as conceptually interlinked (Rambonilaza et al. 2015, Sayles and Baggio 2017, Buitenhuis and Dieperink 2019, Restemeyer et al. 2019, Barrett et al. 2021). Others apply concepts such as evolutionary governance theory (Daniell et al. 2020), adaptive management (van der Voorn et al. 2017), reflexive governance (Barrett et al. 2021), or social-ecological network analysis (Sayles and Baggio 2017). Thus, governance, to be conceptualized as an analytical approach rather than a descriptive umbrella term, remains an under-explored issue with theoretical applications currently beginning to emerge.

This contrasts with highly specialized governance fields, such as coastal landscape governance, where a distinction between concepts of operationalization and conceptualization appears to be already possible (Gonçalves and Pinho 2022). Social science research on estuary governance, on the contrary, is mostly characterized by practical applications and investigations that attempt to empirically uncover regional conditions of singular estuaries through case studies or comparative analyses of different places. Such efforts do not contribute to conceptual clarity as they are tied to empirical cases and often lack theoretical reflection. However, recent comparative studies suggest a common research direction emphasizing the need to further knowledge and conceptual exchange for a theoretically sound and empirically feasible development of estuarine areas and estuary governance (e.g., Vanderlinden et al. 2017, Pinto et al. 2018b, Daniell et al. 2020, Kuenzer et al. 2020). Natural science research, which is developing models and modifications at a higher theoretical level, are here conceived as being used to integrate and consolidate its concepts. What is often missing, though, is an interdisciplinary, process-oriented approach that in many cases lacks an effective transfer and theoretical reflection of these concepts into governance studies.

One notable observation, furthermore, is that a common conceptual definition of governance or spatial demarcation does not exist within the field. This appears to be in line with Kooimann (1999, as cited in Gailing and Röhring 2016), who argues that governance often serves as a rather vague umbrella term that primarily describes “how things are” in a descriptive way. Similarly, Ansell et al. (2022:2) state that governance is “a popular but notoriously slippery term.” This imprecision is also apparent for the use of the term “estuary governance,” which is reflected in empirical-descriptive commonalities and recurring themes such as priorities, chains of rules, policies, institutions and their dynamic interactions with society, policy, and actors. As it stands, research on estuary governance primarily aims at defining and implementing the management of the estuary and its natural resources by decision-making processes (Fidélis et al. 2019, Daniell et al. 2020) although it often lacks Kooimann’s (1999) aspect to combine descriptive “stock-tacking” with a normative evaluation of legitimacy and effectiveness.

Against this background, we rely on Fidélis et al. (2019), who were among the first to conduct a more detailed literature review on estuary governance. They showed that the term “estuary governance” is used either as an explanation for existing problems or as a potential solution in empirical fields like fisheries, water management, or climate change impacts. Moreover, they address conceptual issues such as adaptive management, integrated planning, stakeholder engagement, and legal frameworks. Using these insights as our starting point, we refined Fidélis et al.’s analysis (2019) by demonstrating that studies dealing with estuary governance use the term and/or concept of governance with varying degrees of semantic and conceptual consistency: governance is presented as (1) a relevant factor in the discourse, but remains conceptually vague; (2) an integrative or interdisciplinary approach while it holds the potential to become (3) its own research field with greater conceptual clarity.

To recapitulate:

First, most studies use the term “governance” as a background context, a surrounding condition, or an underlying prerequisite in the estuary region. Estuary governance is usually framed as a minor subject within studies and referred to as a supplementary construct of the system context or state of its existence. Here, estuary governance is mainly framed as an influencing factor of the system context and mostly relegated to decision-making processes. The current lack in research consists in the fact that it frames governance in a descriptive way, but does not conceptually or theoretically explain why governance is part of the system context and what this perspective entails. For instance, Adams (2014:461) emphasizes that “strong governance structures are [...] needed,” while Sayles (2018:73) underlines the need for “enhancing governance network[s].” However, it is not clear how these aims could be achieved while the system context of estuary governance is informed by concepts such as hierarchical, polycentric, collaborative, and network governance (Eger and Courtenay 2021).

Second, integrative and interdisciplinary approaches frame the concept of governance as a component of decision-making processes or decision-support tools. For example, in decision-support tools, ecosystem services—or in adaptive management, scientific knowledge—are integrated into or inform governance principles and processes with the aim to improve decision making in estuary management (e.g., Sousa and Alves 2020, Dapilah et al. 2021, Urlich and Hodder-Swain 2022). As a result, research focuses on developing strategic solutions and achieving goals, or refers simply to enhancing estuary governance. Thus, governance is functionally seen as an integrative approach but conceptually lacking interdisciplinary integration in various disciplines (Zaucha et al. 2016).

Third, there is a growing but still limited body of research that focuses on establishing estuary governance as an independent object or field of research (e.g., Carvalho and Fidélis 2013, Fidélis and Carvalho 2015, Fidélis et al. 2019). Daniell et al. (2020), estimate that “as the effects of climate change unfold, the call for estuary governance theory will only get stronger.” They developed an analytical framework to improve estuary governance by using a combination of theories, such as evolutionary governance theory, risk governance theory, and territorial intelligence theory, possibly contributing to alternative governance models of estuarine areas. Whether this development contributes to establishing estuary governance as an independent field of research remains open.

In sum, our systematic review indicates that research on estuary governance is still in its infancy. It was first introduced in 1987 (Hennessey and Robadue 1987) and has since then conceptually remained unspecified. However, there has been a noticeable increase in its conceptual exploration since 2010, showing that scholars have recognized the relevance of understanding and improving governance mechanisms specifically tailored to estuary environments. A lack of clarity adds to a fuzziness that can be attributed to the limited number of scholars addressing conceptual issues revolving around estuary governance and the vague umbrella term “governance” itself. Yet, we were able to identify some common trends despite the relatively limited body of theoretical work in the scientific literature: (1) estuary governance is closely associated with multi-level governance (MLG); (2) the field is generally characterized by an applied rationale and a lack of conceptual issues; and (3) estuary governance does not to date represent an independent field of research.

A FRAMEWORK FOR COLLABORATIVE ESTUARY GOVERNANCE

As based on our systematic review, we address the gaps identified in research and provide a more structured perspective on the discussion. Estuary governance needs to be combined with a different approach that enables it to better deal with the intricacies of estuaries. Thus, we propose and argue that collaborative governance holds a vital potential for improvement as it foregrounds environmental and conflict dimensions, reveals governance blind spots through a structured analytical approach, and prioritizes stakeholder engagement, an aspect of particular relevance for transboundary estuary governance. However, it represents an approach that is a widely used term in academic literature, but at the same time encompasses many concepts, leading to confusion (Batory and Svensson 2019). To deal with this fuzziness, researchers have developed several analytical frameworks based on literature reviews to provide structure (Bryson et al. 2006, Ansell and Gash 2008, Emerson et al. 2012, Bingham and O’Leary. 2015). Of these frameworks, Ansell and Gash (2008), Emerson et al. (2012), and Emerson and Nabatchi (2015a) were selected as they combine and synthesize theoretical frameworks and research findings with practical implications, providing a promising conceptual basis for application in estuary governance. Specifically, Ansell and Gash (2008) define collaborative governance more structure-oriented than process-oriented, as a formal consensus-oriented process involving public agencies while including non-state stakeholders in decision making to create or implement public policy or manage public programs. Broadening the definition, Emerson et al. (2012) embrace processes within structures with a focus on human activity, as collaboration of people engages across spheres to achieve public purposes. This resulted in introducing a comprehensive framework for collaborative governance regimes (CGRs) (Emerson and Nabatchi 2015a) that is characterized by long-term, cross-boundary collaboration among autonomous participants aiming for collective goals.

Building on Emerson et al.’s (2012, Emerson and Nabatchi 2015a) considerations, we aim to provide elements for a collaborative governance estuary regime. We strive to design a framework inclusive enough to encompass not only institutionalized governance arrangements (e.g., CGRs), but also less formalized collaborative approaches, short-term collaborations, and cooperation that does not lead to (legitimized) decision making in estuarine contexts. To cover these different types, we stick in general to the term “collaboration” and to Emerson et al.’s (2012, Emerson and Nabatchi 2015a) empirically and theoretically grounded framework as its goal is to “identify general components and elements of collaborative governance” (Emerson and Nabatchi 2015a:22). In line with Ansell and Gash (2008), Emerson et al. (2012) and Emerson and Nabatchi (2015a), our systematic literature research has considered the most important dimensions and elements of collaboration. This necessitates exploring when, where, why, how, and under which circumstances collaborations can effectively be applied in estuarine contexts and has led us to expand Emerson and Nabatchi’s (2015a) system context to include the two aspects of environment and conflict. Within collaboration itself, we highlight the relevance of elements such as stakeholder engagement, knowledge integration, structures and processes, and leadership, as they play a central role in estuary governance. In sum, we combine the concept of collaborative governance with the most relevant aspects identified in the estuary governance literature to develop conceptual building blocks for an integrated collaborative estuary governance framework.

Our framework for collaborative estuary governance, as shown in Fig. 2, includes contexts in which collaboration takes place and elements of operationalizing collaboration are displayed. The environmental context, the system context, and conflict dimensions are conceived as interlinked, and a variation where one of the dimensions can influence the other and vice versa can lead to feedback loops. In addition, temporal or contextual perspectives and dynamics that distinguish between historical, current, and expected future changes (with an awareness of their uncertainty, particularly with climate change-related aspects) bear an influence on the dimensions. Through their interactions, these three dimensions catalyze the starting condition(s) for a collaborative dynamic to emerge that could be a CGR or a less formalized collaborative governance arrangement, while within collaboration, participants engage in collaborative dynamics. Based on our meta-synthesis, the collaborative dynamics in the estuary region are conceptualized as the combination of four elements: stakeholder engagement, structures and processes, knowledge integration, and leadership. The institutional design comprises the organizational structures to normalize interactions. Through stakeholder participation in collaborative dynamics, outputs and outcomes may emerge, and intermediate or final outcomes of collaboration can generate adaptation or adaptive responses within the CGR and the surrounding context (Emerson and Nabatchi 2015b). Collaboration can thus lead to “(non-)response” in the environmental context, to “(mal-)adaption” in the system context, and ideally to “negotiation” of conflicts.

Although we build on the contributions of existing frameworks of collaborative governance, our emphasis is motivated by the specific characteristics and needs of estuarine systems. It is based on the thematic blocks we developed in our systematic analysis and which are summarized as dimensions/elements, aspects, and analytical foci as shown in Table 1.

The environmental context dimension

The environmental context dimension significantly shapes collaborative estuary governance, serving not only as “environmental influences that affect and are affected by the CGR” (Emerson et al. 2012:5), but also as a key context in conjunction with the system and conflicts context. The focus on the environmental context dimension is inspired by scholars of environmental governance, who have emphasized the need to understand its dynamics and outcomes in specific contexts (Koontz and Newig 2014, Emerson and Nabatchi 2015a, Clement et al. 2020), and to which particular attention should be paid (Ostrom 2009, Bodin 2017). By environmental context, we refer to all environmental conditions, the current state, and the changes that were and are specific to and present in the ecological shape of estuaries.

Moreover, the meta-synthesis reveals that environmental aspects have typically been assigned a peripheral role and were treated as isolated components of sea, river, or land issues in single-estuary studies, rather than being framed as conceptually linked factors. Given the absence of a comprehensive perspective and superordinate conceptual approaches, as well as the topical segmentation of environmental concerns within the debate on estuary governance, the question arises: how can the environmental context be analyzed in its full scope?

Within the existing scientific literature, environmental protection represents a primary goal (Hein and Thomsen 2022). This can include, for example, protecting unique ecological characteristics of flora and fauna, promoting biodiversity conservation, or establishing processes, such as environmental flows (Adams 2014). Thus, nature conservation and ecological restoration represent the most commonly discussed objectives in estuary governance literature (Carvalho and Fidélis 2013, Root-Bernstein and Frascaroli 2016, Buitenhuis and Dieperink 2019, Elliott et al. 2019, Truchet et al. 2022).

Direct or indirect challenges to deal with in environmental contexts are often referred to as environmental problems (Scott 2015) directly affecting the estuarine environment and its environmental conditions (Sayles and Baggio 2017, Sayles 2018), including crucial ecosystem condition indicators, such as temperature, salinity, oxygen levels, and chemical and nutrient pollution (eutrophication). Indirect pressures on the environmental system, such as nutrient overloading excesses (Pinto and Marques 2015), result from a variety of human activities, such as agriculture, fisheries, urban and industrial development (Ballinger and Stojanovic 2010), leisure activities, and regional and local recreation (Hein and Thomsen 2022).

Further challenges arise from current and anticipated environmental changes due to climate change, which have gained growing recognition in estuaries regions (Dawson et al. 2011, Peirson et al. 2015, van der Voorn et al. 2017, Pinto et al. 2018a). Drawing on the natural science literature, environmental change appears to raise challenging questions for estuary governance: how should it address and deal with increasing environmental impacts (Hoegh-Guldberg and Bruno 2010, Rybczyk et al. 2012, Dapilah et al. 2021, Biguino et al. 2023)? This question is mirrored in the calls for a shift toward a more inclusive, deliberative, and adaptive governance to deal with the impacts of climate change (Turner et al. 2016, Liski et al. 2019b, Sousa and Alves 2020), whereas studies generally show that understanding the impacts of climate change is important for developing and improving sustainable management strategies (Lonsdale et al. 2022).

The lack of an integrated perspective is also acknowledged. For example, Sayles and Baggio (2017) note that environmental problems are often conceptually separated from their ecological and social context, leading to a governance of environmental problems by networks of people and organizations that are only loosely or hardly related to the underlying ecological system. Furthermore, a mismatch often exists between timescales of environmental change and human management responses, particularly with regard to political election cycles (Thomas and Koontz 2011). So, to effectively address estuarine challenges and to better depict the full environmental context of estuaries with regard to environmental concerns, it is essential to consider institutional and political frameworks² such as the European, national, and local policy levels (Dawson et al. 2011). This would include building an understanding of the existing linkages between human and physical systems (Ballinger and Stojanovic 2010).

Although environmental aspects are dominant themes in estuary governance literature, this should not lead to the conclusion that a focused debate on the concept of the entire estuarine system exists. Instead, the current discussion is characterized by a wide and sometimes unspecific array of thematic or spatial components of the estuary such as water, land, and sea, along with their ecological aspects, functions, and problems due to institutional rationales and inflexible structures. Following Daniell et al. (2020), it is important to raise awareness of the spatial and functional interactions within the estuarine environmental system itself.

To overcome the fragmentation of the current debate in estuary governance, interdisciplinary research is key in developing integrated and effective approaches for collaboration in estuary governance. As individual disciplines are unable to comprehensively and cooperatively analyze the environmental context of an estuary, trustworthy interdisciplinary research is paramount. A basic level of mutual understanding across disciplines would be a starting point to enable analyses that draw on existing social and natural science studies to develop interdisciplinary and integrative cooperation. This would, for example, include targeted social science field studies that could reveal and sensitize natural science and engineering disciplines for stakeholder knowledge, local perceptions, and regional practices of dealing with or solving problems. Although this is sometimes a difficult process and seems like a fundamental task, recognizing the commitment to collaborative decision making is essential for developing sustainable management strategies and dealing with the various impacts of climate change on estuaries.

In sum, effective collaborative governance requires not only the understanding of the environmental context and the local specificities of each estuary, but also its relationship between the different contexts. On this note, our framework (Fig. 1) helps to understand the dimensions and nuances of environmental contexts in interaction and non-interaction with the system context, and the existing conflicts. By understanding the multifaceted nature of the socio-conflictual-environmental estuary contexts and prioritizing governance actions based on their potential environmental impacts, governance efforts hold the potential to more effectively address the challenges caused by global environmental change and human activities.

The system context dimension

The system context in which a collaborative governance arrangement operates can both facilitate and hinder collaboration dynamics and efficiency (Ansell and Gash 2008, Emerson and Nabatchi 2015a). Like the environmental context, the system context of estuary regions is multifaceted as it operates at multiple scales, involves multi-resort responsibilities, is embedded in highly political-administrative structures, is affected by overlapping jurisdictions, has a diverse actor constellation, and is subject to policy priorities and decision-making frameworks. The meta-analysis clearly reveals that the system context is characterized by existing institutional constraints and competing interests lacking awareness of horizontal and vertical governance processes. The complicated situation in estuaries often obfuscates or even discourages system context analyses in existing research (Daniell et al. 2020), resulting in a focus on addressing practical, isolated, and confined governance challenges.

The concept of collaborative governance provides here a basis for analyzing the system context. As outlined by Emerson and Nabatchi (2015a), the system context is classified into political (e.g., political structures, decision-making processes, political interests), social (e.g., communities, population, social interactions, cultural factors), and economic (e.g., economic activities, resource management, economic interests) dimensions. The system context of collaborative governance can also be characterized in terms of multi-level governance (MLG), spanning public and private sectors (Emerson et al. 2012). Crucial are here the following questions: what are the specifics of each estuary’s systemic context? And within which horizontal and vertical governance structures should collaboration be embedded?

The current debate on estuary governance acknowledges influences from the global to the local level. At the global and supranational level, international treaties and conventions set at least minimum environmental protection standards, whereas at the national level, government policies regulate marine, coastal, and federal waterways. At the regional and local levels, estuarine specifics are addressed through laws and regulations (Lonsdale et al. 2022). However, although higher-level legislative instruments and obligations primarily set implementation goals without specifying how to achieve them, they induce but also enable, different and localized interpretations and implementations by local estuary governments (Daniell et al. 2020, Sousa and Alves 2020).

Estuary regions—framed in terms of administrative boundaries—rarely align with ecosystem boundaries, reflecting the fragmented nature of estuary governance systems, which are made up of isolated components such as land-use planning, marine planning, economic development, and natural resource management (Daniell et al. 2020). Due to their varying characteristics, these subsystems are already in conflict within each other and with politics, economics, law, and sectoral views. Defining and analyzing appropriate scales and levels for governance arrangements is challenging, and estuaries are in many cases not considered as a multifaceted entity by decision makers (Daniell et al. 2020).

The spatial–scale mismatch, which describes the misalignment of governing bodies with environmental systems, represents another challenge (Sayles and Baggio 2017). Examples, such as urban and rural upstream community members being unaware of their impact on downstream fishing and aquaculture industries, exhibit the discrepancy between different stakeholder priorities and the resulting need for overarching governance approaches (Daniell et al. 2020). However, positive examples illustrate that awareness of these interdependencies is increasing: fishery managers collaborate to manage migratory fish populations, and municipal park managers cooperate with other land managers within pollination distance of the park (Sayles and Baggio 2017).

Institutional challenges represent a further barrier for effective estuary governance. For example, issues such as problems of coordination between agencies are a hindering point (Carvalho and Fidélis 2013), and time constraints for the development of studies, plans, and comprehensive evaluations represent vital barriers as well (Sousa and Alves 2020). Additionally, high transaction costs due to geographical distribution of agencies (Sayles 2018) lead to a reluctance to engage with issues, such as for example flood protection in England, where flood risk management responsibilities are divided among a variety of stakeholders (Restemeyer et al. 2019). In general, governance processes are shaped at the regional and local level, and the historically generated path-dependencies at both state and local levels. Overlapping laws and procedures, along with persistent historical influences of various kinds, influence the administrative and socio-political processes that impact on horizontal governance development in estuary regions (Boschet and Rambonilaza 2018).

Another challenge for estuary governance consists in building a common understanding of the interaction between social and political aspects within ecological systems (Root-Bernstein and Frascaroli 2016). Urlich and Hodder-Swain (2022), for example, discuss the importance of cultural values and religious aspects for inhabitants of estuaries, such as the Maori of New Zealand, who are spiritually connected to their estuary.

So far, the debate on the estuary system context has mainly focused on the ability of divided and segregated management approaches on a regional or local level to operationalize their respective governance conceptualization. This also concerns small-scale management arrangements that take place in a larger context, and it is not discussed how exactly these efforts have a horizontal and vertical effect. We found that estuary governance often occurs in “silos,” with the sea, the river, and the land being managed separately, whereas interactions between upstream and downstream communities are intricately interwoven. This is exacerbated by the fact that estuaries do not spatially align with the legally and culturally defined categories of land and sea, which makes the process of defining, understanding, or developing their system context tricky (Daniell et al. 2020).

To conclude, clarifying the horizontal and vertical governance interrelations is paramount to ensure consistent and effective collaborative arrangements across all levels and administrative boundaries. The system context is crucial for estuary governance, comprehensively including structures, rules, power dynamics, and stakeholders, and reproduced on a smaller scale within collaborations. Identifying potential barriers supports the effectiveness of any governance modi.

The conflict context dimension

The ongoing discourse on collaborative governance in the literature has repeatedly emphasized the benefit of conflict resolution through collaboration (Berardo et al. 2014; see also: studies of environmental conflict research by Scarff et al. 2015, Hileman and Bodin 2019). As the meta-analysis exhibited, conflicts are core topics in social sciences studies on estuary governance, identifying a high potential for and diversity of conflicts across various levels and scales in estuary regions (for overviews, see Carvalho and Fidélis 2013, Fidélis and Carvalho 2015). We identified the conflict context as a stand-alone dimension with the need to clearly define estuarine conflicts within conflict research streams as based on Stepanova and Bruckmeier (2013) and Kuhn et al. (2023), who have been working intensively on coastal and environmental conflicts.

The existing literature on estuary governance reveals different types of conflicts such as socio-environmental conflicts (Truchet et al. 2022), use conflicts (Carvalho and Fidélis 2013), or land-use conflicts (Pinto et al. 2018a). Research on these topics shows that conflicts tend to be historically embedded, long-standing (Barrett et al. 2021), deeply rooted among local actors (Root-Bernstein and Frascaroli 2016), and/or arising from competing objectives in different sectors, such as environmental protection, agriculture, or industry (Peirson et al. 2015).

Ballinger and Stojanovic (2010) argue that conflicts in estuary regions are mainly caused by existing interconnections of human and physical systems, ranging from global perspectives, such as global environmental change and sea level rise (Pinto et al. 2018b) to more regional and local issues, such as pollution and habitat degradation (Pinto and Marques 2015). External and internal threats can be distinguished as potentials for conflict (Kuenzer et al. 2020). External factors include climate change, environmental pollution, and political conflicts, whereas internal factors may for example include oil or industrial pollution and land subsidence. As well, decision making often prioritizes socio-economic interests over ecological ones (Atkins et al. 2011, Truchet et al. 2022).

As seen in our review, conflicts in estuary regions increasingly have environmental roots and “outside conflicts” driven by estuarine factors often lead to “inner governance and institutional conflicts” such as litigation, deadlock, or stakeholder disagreements. Consequently, a comprehensive consideration of the three dimensions (environmental context, system context, and conflict context) and their interaction is pivotal because conflicts do not arise overnight, but are significantly influenced and shaped by already existing as well as newly emerging factors. In our view, it is important that estuary governance will develop further by emphasizing that conflict negotiation and mediation can only be successful through an integrative socio-environmental understanding of estuary regions.

Starting condition element

Whereas the previous three dimensions provide the contextual backdrop, the starting condition element emerges from their interactions, thereby marking a transition from these contexts into the institutionalization and operationalization of the collaboration. The rationale for initiating a collaboration in estuary regions depends, to a considerable extent, on the starting condition “which can either facilitate or discourage cooperation between stakeholders and between agencies and stakeholders” (Ansell and Gash 2008:550), with Emerson et al. (2015a) identifying four key drivers for collaboration: uncertainty (e.g., individual or collective uncertainty about the nature, scope, or consequences of an issue), interdependence (e.g., actors can not achieve goals independently), consequential incentives (e.g., internal needs such as resource needs, interests, or opportunities, and external pressures, such as crises, threats, or opportunities), and initiating leadership (e.g., a recognized actor who can mobilize support and resources).

For collaboration within an estuary region, very few studies provide insights into drivers. Increasing awareness of the interdependence of stakeholders’ interests and socio-environmental risks affecting estuaries has been shown as one example (Carvalho and Fidélis 2013). Conflicts (Truchet et al. 2022) can be conceived as the primary driver as collaborative governance is primarily site specific and closely tied to specific issues within an estuary region (Emerson et al. 2003, as cited in Emerson and Nabatchi 2015a). Such drivers can stem from a variety of reasons: uncertainty in dealing with “turbulence” (Bryson et al. 2006, as cited in Emerson 2015a) and “wicked” problems, such as climate change, which are currently gaining momentum in the estuary governance debate (Emerson and Nabatchi 2015a, Voets et al. 2014). Furthermore, stimuli, both negative (e.g., extreme weather events) and positive (e.g., environmental funding), also have the potential to serve as a motivational force for collaboration.

To conclude, the starting condition element functions as the catalyst among the three dimensions. Understanding the starting conditions and drivers enables identifying potential impediments for collaboration, including mistrust among stakeholders or historically established objections, which may impede collaboration dynamics. Overall, the state, its institutions, and its representatives hold the primary responsibility and power for initiating collaboration.

Institutional design element

The institutional design element refers to those arrangements that have to be established both at the intra- and the inter-organizational level (Emerson et al. 2012). In addition, constitutive decision-making processes are considered to require (re-)design and establishment (Emerson and Nabatchi 2015a). Effective collaborative governance prioritizes the principles of openness and inclusiveness (Ansell and Gash 2008), procedural transparency, legitimacy (Bryson et al. 2006, Dapilah et al. 2021), and well-balanced accountability (Ulibarri et al. 2023).

Taking these aspects as a starting point for collaboration in estuary regions, the exploration of estuarine-specific institutional design requirements depends on the respective system context. As estuary regions are characterized by a multitude of stakeholders and may span multiple nations, regions, and governance sectors at different governance levels, the implementation of a robust collaborative governance arrangement is particularly challenging. Collaboration processes are time consuming and highly dependent on interests and the political environment (Gash 2022). Yet, they hold the potential to enable the sharing and leveraging of scarce resources (Emerson and Nabatchi 2015a).

A critical step in institutional design is a well-defined and collaboratively developed set of goals, as the absence of clear goals can lead to difficulties in reaching and assessing outcomes, leading to stagnation and impasses (Gash 2022). As higher-level visions are seen as a key factor in the development of estuary regions in the scientific literature, developing them is conceived as a first and foremost goal (Pinto et al. 2018b, Buitenhuis and Dieperink 2019, Lonsdale et al. 2022). Thus, the more diverse and conflicting interests are, the more essential it is to implement clear and robust institutional design arrangements to ensure effective collaborative outputs and outcomes.

Output and outcome element

Implementing actions of collaboration dynamics hold the potential to lead to outputs and outcomes (Emerson and Nabatchi 2015a). Outputs are short-term and direct results, such as the concrete identification of recommendations for and the implementation of actions, whereas outcomes are long-term and indirect results, such as trust built between stakeholders, established democracy in practice, increased transparency of processes and conflicts, reduced litigations, or extended perception of environmental change. Nevertheless, Emerson and Nabatchi (2015a) remark that even if collaboration fails to achieve formal outputs, the emergence of social benefits and potentially positive outcomes is still possible.

Despite the lack of information on collaborative outputs and outcomes in estuary regions, the scientific literature reveals a need to improve environmental aspects in estuary regions with regard to sustainability (Barrett et al. 2021), restoration (Root-Bernstein and Frascaroli 2016), and ecological outcomes (Sayles 2018). Recent studies on collaborative governance, however, indicate that environmental outcomes often do not align with political agendas, although collaborative processes have beneficial effects on them (Biddle and Koontz 2014). Whether the effectiveness of these outputs and outcomes in fragmented estuary regions can lead to environmentally friendly policy decisions, their subsequent implementation, or result in implementation gaps remains to be proven.

Structures and processes aspect

Collaborative estuary governance arrangements can vary, depending on factors like affordability, initiators, leadership, participants, and goals. These structures and processes must operate within the constraints of legal and institutional frameworks and decision-making authorities while defining roles, competencies ,and goals of the collaboration that also ensure transparency. These structural aspects are essential for guiding iterative interactions among multiple participants over time (Emerson and Nabatchi 2015a). As collaborative estuary governance regimes are likely large, interdependent, and long lasting, they share similar requirements to those of other governance areas: establishing clear ground rules, maintaining transparency of processes, formalizing governance structures of expectations, processes, and outcomes, and adhering to formal deadlines within the organizational structure (Ansell and Gash 2008).

Stakeholder engagement aspect

Within the discourse on estuary governance, stakeholder engagement has been identified as one of the key topics (e.g., Zaucha et al. 2016). All studies identify stakeholder engagement as a key factor within the success and acceptance of effective estuary governance. Emerson et al. (2012:10) refer to stakeholder engagement as “principled engagement,” which aims to assess the level of trust and mutual respect between potential stakeholders before forming the collaborative governance arrangement. This is essential, as relationships are conceived as the foundation of collaborative governance (Ansell and Gash 2008, Emerson et al. 2012). According to Ansell and Gash (2008), access should also be given to all stakeholders, including potentially conflicting interests. However, who the “right” or “adequate” stakeholders to be involved in the estuary governance are remains to be answered.

Generally seen, the estuary governance literature discusses that a person or interest group qualifies as a stakeholder by representation, legitimacy, power, and knowledge (O’Toole et al. 2013). According to the systematic review, state and non-state stakeholders in estuary governance processes can originate from various entities, such as port authorities, scientific research centers, municipalities, industries, and user associations representing fishermen, salt producers, agriculturalists, hunters, and water sports enthusiasts (Lillebø et al. 2015). So-called stakeholders are often categorized or differentiated on the basis of their importance, role as mediators, and levels of dominance and power within the decision-making process (e.g., Liski et al. 2019a). Buitenhuis und Dieperink (2019) underscore the role of key stakeholders in influencing processes and outcomes.

Shared goals, visions, long-term commitment, and pathway development of estuarine stakeholders are seen as a basic requirement for effective and long-lasting management and adaptation strategies to climate change (van der Voorn et al. 2017, Liski et al. 2019a, Sousa and Alves 2020). A key advantage of stakeholder engagement in estuary governance is that it leads to decisions that are more closely aligned with community values and needs, incorporate local knowledge, reduce mistrust (Vanderlinden et al. 2017), and foster effective mediation of interests, social learning, and negotiation across scales (Sousa and Alves 2020).

However, stakeholder behavior may also hinder collaborative governance or even cause it to fail. Research indicates that there is not always sufficient representation and integration of stakeholders in estuarine governance processes (Root-Bernstein and Frascaroli 2016). This failure can result in regional resistance (Buitenhuis and Dieperink 2019). Also, there often exists a lack of sufficient resources within the participating organizations for coordination and collaboration, as well as the effect of mutual influences between higher- and lower-level organizations (Sayles 2018).

In sum, an estuary collaboration has much to gain and also much to lose from successful or unsuccessful involvement of stakeholders. Finding the right balance seems to be a challenge, given the conflicting perspectives and the need to promote democratic and equitable processes in estuary regions. The tendency to use stakeholder engagement as a panacea aiming to quickly satisfy the needs of various interest groups can have negative impacts if it is not done properly or in earnest, as individuals feel that they are only allowed to collaborate for the sake of formal participation without having sufficient influence or impact. The scientific debate on estuary governance shows that its importance has already been recognized, but we suggest taking a step back and examining the current and future purpose of engagement and what it actually is: stakeholder engagement should be reflected from a more conceptual perspective to avoid fallacies of the practical side.

Knowledge integration aspect

The knowledge integration element is one of the elements of Emerson et al.’s (2012) attributed capacity for joining action. According to them (Emerson et al. 2012:16), “knowledge is the currency of collaboration,” and collaboration requires the generation and sharing of new knowledge. This aspect has been outlined in studies that explicitly address the role of knowledge management for collaboration in networks (Agranoff 2007 and Cross and Parker 2004 as cited in Emerson et al. 2012).

Despite the multiple meanings and interpretations of the notion of knowledge, the literature on estuary governance recognizes the benefits of integrating various types of knowledge into governance processes. Scholars in the field of estuary governance generally agree that local knowledge plays an important role (Sousa and Alves 2020, Barrett et al. 2021) and that it can contribute to reduce regional resistance (Buitenhuis and Dieperink 2019), whereas local ecological knowledge (Truchet et al. 2022) and expert knowledge are valuable for developing and assessing (extreme) future scenarios (Dawson et al. 2011). This can, for example, be seen in the ecological knowledge of fishermen about the impacts of climate change on fish populations or the long-term changes in the maritime environments (Truchet et al. 2022).

Climate change, especially, requires the integration of different types of knowledge and a transdisciplinary approach for a more comprehensive understanding of the multifaceted relationships in estuarine ecosystems (Sousa and Alves 2020). Buitenhuis and Dieperink (2019) propose so-called knowledge brokers for managing “knowledges” because scientific knowledge does not represent a panacea and its incorporation into decision making is currently limited (Vanderlinden et al. 2017).

So far, research on knowledge and knowledge integration mostly remains on a descriptive level without explaining how to successfully implement them in estuary governance. It remains unclear how knowledge is generated and used within collaboration, the impact it bears on participants and their ability to understand and apply it, and its strategic influence on conflicts. However, local estuarine knowledge, the acceptance of different forms of knowledge (tested knowledge, experience-based knowledge, informal, formal, and lay knowledge), and the fostering of a common understanding of the estuarine system are pivotal for the envisioned collaboration.

However, with the impending climate-induced environmental changes and the increasing scientification of governance processes (Bogner 2021), the necessity of required knowledge and its limitations in the face of uncertainties becomes evident. Also, scientific knowledge and findings cannot be used as the sole basis or justification for decisions to be made. Thus, after an analysis of what types of knowledge are available, used, or needed, there should also be a reflection on the extent to which knowledge should or can be used by policy makers, administrative staff, and other actors. Generally, a need for further research on methodological, theoretical, and empirical aspects emerges from our analysis, suggesting that a deep understanding of the estuarine system is required for a more effective governance.

Leadership aspect

The aspect of leadership is increasing in significance as a driver of collaborative governance, a development also reflected in the growing body of literature on the subject (O’Leary et al. 2012, Linden 2010, Morse et al. 2007 as cited in Emerson and Nabatchi 2015a). The task of an effective leadership consists in adequately representing all interests, building trust to keep stakeholders engaged and ideally trying to minimize conflicts (Ansell and Gash 2008).

As it stands today, a limited focus on the topic and concept of leadership is prevalent in the scientific literature on estuary governance. However, research undertaken in estuary regions indicates that individuals are important (Buitenhuis and Dieperink 2019), that interests and political leadership are necessary for the implementation of legislation (Liski et al. 2019a), that leadership can come from a superior-level of government (Wang and Gong 2022), that powerful actors matter (Daniell et al. 2020), and that regions are often dominated by economic sectors (Pinto and Marques 2015). Although collaborative leadership is of crucial relevance when power and resources are “asymmetrically distributed” (Ansell and Gash 2008), as it is often the case in estuary regions, effective leadership must bring together a multitude of overlapping entities, institutions, economic sectors, and stakeholders who share resources and hold varying degrees of power (Carvalho and Fidélis 2013, Huang and Xu 2017, Wang and Gong 2022).

What is currently lacking is a theoretical debate about and a clear notion of leadership in estuary governance. This is not surprising as leadership represents a driver of collaborative governance rather than a feature of estuary governance and multi-level governance. Mainly, we see the need for estuarine leaders to act as science translators (Emerson et al. 2012), evaluating and mediating when natural scientists model so-called idealized scenarios of estuaries, and social scientists need to recognize that political decisions involve compromises and trade-offs. As it stands, it is only possible through the implementation of competent leadership and “leadring” (Stibbe 2024) to balance strategies and competing interests of estuarine stakeholders effectively.

CONCLUSION

Estuaries are contested spaces that face significant challenges due to global change, conflicting user demands, increasing human impacts, and climate-induced environmental change. All these factors contribute to the fact that effective estuary governance remains an ambitious endeavor. In line with Gash (2022:507), who stated that “collaborative governance is a high-risk, high-reward policy endeavour,” this paper argues that collaborative estuary governance holds potential for conflict negotiation, system adaptation, and as a response to environmental change. Based on our analysis of the status quo nestling within research, we offered an estuary-specific framework that links collaborative with estuary governance. The aim consisted in providing a more structured conceptual approach by comparing and merging current developments. In doing so, we aimed to productively contribute to the currently developing discourse of estuary governance.

Our systematic inventory of publications on estuary governance captures both the bigger picture on the development of the notion “estuary” and features a meta-synthesis of main thematic clusters, also revealing topical issues. Research on estuary governance is, as it stands, at an early stage if not in its infancy, but it is also gaining more and more attention. Currently, it suffers from a lack of conceptual reflection and theoretical development, and so far, rather represents an object- or problem-oriented field characterized by a descriptive rationale. The “fuzziness” encountered is, as yet, not problematized, and trends to clarify and develop the concept are still scarce. Therefore, our framework of collaborative estuary governance maps out three dimensions (environmental context, system context, conflict context) and three elements (starting condition, institutional design, output and outcomes) as they are conceived as highly relevant in the scientific literature analyzed. Although we are not the first to develop such a framework of collaborative governance (Ansell and Gash 2008, Emerson et al. 2012, Emerson and Nabatchi 2015a), we reveal the use and emphasize the relevance of the to-date neglected, separate dimensions of environmental and conflict context as depicted alongside the system context dimension. Thus, as our analysis is in line with the current state of knowledge, we would like to instigate a reflection on the limits and risks of estuary collaborative governance from our perspective as outlined below:

• Collaborative processes are high risk and time consuming and may be made on the basis of the lowest common denominator. This does not allow for effective or large-scale changes. There is a general risk that processes and their outputs will be blocked at an early stage by private interest groups, actors, or the public, a potential barrier that could be particularly relevant in multi-stakeholder estuary regions.
• Path dependency, representing the historically established routines of institutional problem solving, lack of knowledge about contact partners and institutions, and (non-)action in estuary regions, shaped by their often unclear horizontal and vertical personal–institutional linkages, make fast and large development steps considerably difficult. The so-called “human factor” often leads (state-)actors to adhere to established institutional practices, even in the face of new evidence and insights, until a prevailing consensus emerges to support the “new reality”—even though the decision/action initiated may come too late (climate change).
• The integration of knowledge and the management of uncertainties both social and environmental often lack a strategic approach, leading to decision-making dilemmas, especially under economic constraints. Although uncertainty may initially encourage collaboration, unresolved issues impede practical action and can be deliberately exacerbated, for example, by selective or biased data release, modeling, and interpretation. This highlights the need for transparency, equitable access to data, and strategies to turn uncertainty into actionable steps of doing things.
• Generational challenges and conflicting timescales with long-term solutions often clash with short-term political cycles and limited public resources. Incremental interventions, such as uncompensated river dredging, may seem small but accumulate over time, leaving future generations to deal with decades of maladaptation exacerbated by climate change. Increasing use pressures, particularly of megacities in estuary regions, exhibit this problem. Therefore, collaborative estuary governance should ideally be independent of or even detached from political cycles, allow for longer-term planning and management, have a cross-boundary or international framework, and focus on long-term visions and commitments. It can, however, be highly dependent on individuals or political parties if implemented and supported by elected or unelected representatives.

Despite these limitations, we argue that top-down approaches, power imbalances, and the duration of legislation and established governance principles will reach their limits in the future. Following new research on the subject of robust governance (Ansell et al. 2022), we are convinced that effective estuary governance cannot be thought of separately from its surrounding environmental, societal, and cultural factors. This interconnection should be reflected in the level at which collaboration is implemented. A governance arena accurate for the environmental system functionality of a transnational or intermunicipal estuary—particularly the regional governance arena—could serve as an effective intermediary between local initiatives and broader national and global impacts, enabling project-specific developments at the local level without compromising larger-scale considerations.

Generally seen, only continuous theoretical and empirical discussion, that builds on international comparative studies and interdisciplinary and transdisciplinary knowledge spanning scientific disciplines, sectors, and policy domains, will be able to contribute and build a suitable estuary governance theory. Although alternative approaches, such as adaptive governance (Chaffin et al. 2014) also hold a significant potential, collaborative governance is a flexible approach to effectively address impacts and effects of human interventions and climate change in estuarine environments.

Embracing collaborative estuary governance as a framework can thus provide better understanding of how estuary regions could be sustainably managed, be more resilient to (climate-induced) environmental challenges, as well as just and more equitable for all stakeholders to be involved. In the end, collaboration is about the willingness of estuarine actors and stakeholder to engage in conflict negotiation and mediation, to share knowledge and power, to accept change and to grapple with future development. Whether this will take place remains a challenge for estuary regions in the future.

__________

^[1] For an overview of the seven thematic clusters developed during the systematic literature review, see Appendix 1.
^[2] We are aware that our approach is influenced by our European background, which may pose constraints to the transferability of the framework in other geographical, political, institutional, and cultural contexts.

LITERATURE CITED

Adams, J. B. 2014. A review of methods and frameworks used to determine the environmental water requirements of estuaries. Hydrological Sciences Journal 59(3-4):451-465. https://doi.org/10.1080/02626667.2013.816426

Ansell, C., and A. Gash. 2008. Collaborative governance in theory and practice. Journal of Public Administration Research and Theory 18(4):543-571. https://doi.org/10.1093/jopart/mum032

Ansell, C., E. Sørensen, and J. Torfing. 2022. Public administration and politics meet turbulence: the search for robust governance responses. Public Administration 101(1):3-22. https://doi.org/10.1111/padm.12874

Atkins, J. P., D. Burdon, M. Elliott, and A. J. Gregory. 2011. Management of the marine environment: integrating ecosystem services and societal benefits with the DPSIR framework in a systems approach. Marine Pollution Bulletin 62(2):215-226. https://doi.org/10.1016/j.marpolbul.2010.12.012

Ballinger, R., and T. Stojanovic. 2010. Policy development and the estuary environment: a Severn Estuary case study. Marine Pollution Bulletin 61(1-3):132-145. https://doi.org/10.1016/j.marpolbul.2009.12.020

Barrett, P., P. Kurian, N. Simmonds, and R. Cretney. 2021. Explaining reflexive governance through discursive institutionalism: estuarine restoration in Aotearoa New Zealand. Journal of Environmental Policy and Planning 23(3):332-344. https://doi.org/10.1080/1523908X.2021.1885358

Batory, A., and S. Svensson. 2019. The fuzzy concept of collaborative governance: a systematic review of the state of the art. Central European Journal of Public Policy 13(2):28-39. https://doi.org/10.2478/cejpp-2019-0008

Berardo, R., T. Heikkila, and A. K. Gerlak. 2014. Interorganizational engagement in collaborative environmental management: evidence from the South Florida Ecosystem Restoration Task Force. Journal of Public Administration Research and Theory 24(3):697-719. https://doi.org/10.1093/jopart/muu003

Biddle, J. C., and T. M. Koontz. 2014. Goal specificity: a proxy measure for improvements in environmental outcomes in collaborative governance. Journal of Environmental Management 145:268-276. https://doi.org/10.1016/j.jenvman.2014.06.029

Biguino, B., I. D. Haigh, J. M. Dias, and A. C. Brito. 2023. Climate change in estuarine systems: patterns and gaps using a meta-analysis approach. Science of the Total Environment 858(1):159742. https://doi.org/10.1016/j.scitotenv.2022.159742

Bingham, L. B., and R. O’Leary, editors. 2015. Big ideas in collaborative public management. Routledge, London, UK. https://doi.org/10.4324/9781315706146

Bodin, Ö. 2017. Collaborative environmental governance: achieving collective action in social-ecological systems. Science 357(6352):aan1114. https://doi.org/10.1126/science.aan1114

Bogner, A. 2021. Die Epistemisierung des Politischen. Wie die Macht des Wissens die Demokratie gefährdet: [Was bedeutet das alles?]. Reclam Verlag, Stuttgart, Germany.

Booth, A. 2016. Searching for qualitative research for inclusion in systematic reviews: a structured methodological review. Systematic Reviews 5(74):1-23. https://doi.org/10.1186/s13643-016-0249-x

Boschet, C., and T. Rambonilaza. 2018. Collaborative environmental governance and transaction costs in partnerships: evidence from a social network approach to water management in France. Journal of Environmental Planning and Management 61(1):105-123. https://doi.org/10.1080/09640568.2017.1290589

Boyes, S. J., and M. Elliott. 2015. The excessive complexity of national marine governance systems—has this decreased in England since the introduction of the Marine and Coastal Access Act 2009? Marine Policy 51:57-65. https://doi.org/10.1016/j.marpol.2014.07.019

Bryson, J. M., B. C. Crosby, and M. M. Stone. 2006. The design and implementation of cross-sector collaborations: propositions from the literature. Public Administration Review 66(S1):44-55. https://doi.org/10.1111/j.1540-6210.2006.00665.x

Buitenhuis, Y., and C. Dieperink. 2019. Governance conditions for successful ecological restoration of estuaries: lessons from the Dutch Haringvliet case. Journal of Environmental Planning and Management 62(11):1990-2009. https://doi.org/10.1080/09640568.2018.1529556

Carvalho, T. M., and T. Fidélis. 2013. The relevance of governance models for estuary management plans. Land Use Policy 34:134-145. https://doi.org/10.1016/j.landusepol.2013.02.007

Chaffin, B. C., H. Gosnell, and B. A. Cosens. 2014. A decade of adaptive governance scholarship: synthesis and future directions. Ecology and Society 19(3):56. https://doi.org/10.5751/ES-06824-190356

Clement, S., A. G. Guerrero Gonzalez, and C. Wyborn. 2020. Understanding effectiveness in its broader context: assessing case study methodologies for evaluating collaborative conservation governance. Society and Natural Resources 33(4):462-483. https://doi.org/10.1080/08941920.2018.1556761

Daniell, K. A., R. Plant, V. Pilbeam, C. Sabinot, N. Paget, K. Astles, R. Steffens, O. Barreteau, S. Bouard, P. Coad, A. Gordon, N. Ferrand, P.-Y. Le Meur, C. Lejars, P. Maurel, A. Rubio, J.-E. Rougier, and I. White. 2020. Evolutions in estuary governance? Reflections and lessons from Australia, France and New Caledonia. Marine Policy 112:1-15. https://doi.org/10.1016/j.marpol.2019.103704

Dapilah, F., J. Ø. Nielsen, K. Lebek, and S. A. L. D’haen. 2021. He who pays the piper calls the tune: understanding collaborative governance and climate change adaptation in northern Ghana. Climate Risk Management 32:100306. https://doi.org/10.1016/j.crm.2021.100306

Dawson, R. J., T. Ball, J. Werritty, A. Werritty, J. W. Hall, and N. Roche. 2011. Assessing the effectiveness of non-structural flood management measures in the Thames Estuary under conditions of socio-economic and environmental change. Global Environmental Change 21(2):628-646. https://doi.org/10.1016/j.gloenvcha.2011.01.013

Dorcey, A. H. J. 2004. Evolution of estuarine governance in a metropolitan region: Collaborating for sustainability in the Fraser River estuary. Bulletin of the Geological Survey of Canada 567:247-263 https://doi.org/10.4095/215812

Eger, S. L., and S. C. Courtenay. 2021. Integrated coastal and marine management: insights from lived experiences in the Bay of Fundy, Atlantic Canada. Ocean and Coastal Management 204:105457. https://doi.org/10.1016/j.ocecoaman.2020.105457

Elliott, M., J. W. Day, R. Ramachandran, and E. Wolanski. 2019. A synthesis: what is the future for coasts, estuaries, deltas and other transitional habitats in 2050 and beyond? Pages 1-28 in E. Wolanski, J. W. Day, M. Elliott, and R. Ramachandran, editors. Coasts and estuaries. The future. Elsevier, Amsterdam, Netherlands. https://doi.org/10.1016/B978-0-12-814003-1.00001-0

Emerson, K., and T. Nabatchi. 2015a. Collaborative governance regimes. Georgetown University Press, Washington, D.C., USA.

Emerson, K., and T. Nabatchi. 2015b. Evaluating the productivity of collaborative governance regimes: a performance matrix. Public Performance and Management Review 38(4):717-747. https://doi.org/10.1080/15309576.2015.1031016

Emerson, K., T. Nabatchi, and S. Balogh. 2012. An integrative framework for collaborative governance. Journal of Public Administration Research and Theory 22(1):1-29. https://doi.org/10.1093/jopart/mur011

Fidélis, T., and T. Carvalho. 2015. Estuary planning and management: the case of Vouga Estuary (Ria de Aveiro), Portugal. Journal of Environmental Planning and Management 58(7):1173-1195. https://doi.org/10.1080/09640568.2014.918874

Fidélis, T., F. Teles, P. Roebeling, and F. Riazi. 2019. Governance for sustainability of estuarine areas—assessing alternative models using the case of Ria de Aveiro, Portugal. Water 11(4):846. https://doi.org/10.3390/w11040846

Gailing, L., and A. Röhring. 2016. Is it all about collaborative governance? Alternative ways of understanding the success of energy regions. Utilities Policy 41:237-245. https://doi.org/10.1016/j.jup.2016.02.009

Gash, A. 2022. Collaborative governance. Pages 497-509 in C. Ansell and J. Torfing, editors. Handbook on theories of governance. Edward Elgar Publishing, Cheltenham, UK, and Northampton, Massachusetts, USA.

Gonçalves, C., and P. Pinho. 2022. In search of coastal landscape governance: a review of its conceptualisation, operationalisation and research needs. Sustainability Science 17(3):2093-2111. https://doi.org/10.1007/s11625-022-01147-6

Hein, J., and J. Thomsen. 2022. Contested estuary ontologies: the conflict over the fairway adaptation of the Elbe River, Germany. Environment and Planning E: Nature and Space 6(1):153-177. https://doi.org/10.1177/25148486221098825

Hennessey, T., and D. Robadue, editors. 1987. Lessons from the experiment in estuarine governance: establishing evaluative criteria. Pages 1685-1690 in P. Seligman, R. Williams, M. Waldock, E. Brainard, L. Hall, R. Coates, W. Johnson, A. Valkirs, J. Keeley, R. Huggett, P. Stang, M. Stephenson, C. Goudy, J. Irish, R. Macnab, T. Carter, S. Smith, R. Abel, K. Manchester, M. Kumar, N. Saxena, I. Townsend-Galt, F. Cantelmo, J. Summers, and G. Kontopidis, editors. Proceedings of OCEANS’87, Halifax, Nova Scotia, Canada, 28 September 1987–1 October 1987. IEEE, New York, New York, USA. https://doi.org/10.1109/OCEANS.1987.1160587

Hileman, J., and Ö. Bodin. 2019. Balancing costs and benefits of collaboration in an ecology of games. Policy Studies Journal 47(1):138-158. https://doi.org/10.1111/psj.12292

Hoegh-Guldberg, O., and J. F. Bruno. 2010. The impact of climate change on the world’s marine ecosystems. Science 328(5985):1523-1528. https://doi.org/10.1126/science.1189930

Huang, Q., and J. Xu. 2017. Scales of power in water governance in China: examples from the Yangtze River Basin. Society and Natural Resources 30(4):421-435. https://doi.org/10.1080/08941920.2016.1268657

Imperial, M. T., T. Hennessey, and D. Robadue, Jr. 1993. The evolution of adaptive management for estuarine ecosystems: the National Estuary Program and its precursors. Ocean and Coastal Management 20(2):147-168. https://doi.org/10.1016/0964-5691(93)90056-5

Intergovernmental Panel on Climate Change (IPCC). 2019. The ocean and cryosphere in a changing climate. Special report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK, and New York, New York, USA. https://doi.org/10.1017/9781009157964

Jabareen, Y. 2009. Building a conceptual framework: philosophy, definitions, and procedure. International Journal of Qualitative Methods 8(4):49-62. https://doi.org/10.1177/160940690900800406

Kooiman, J. 1999. Social-political governance: overview, reflections, and design. Public Management: An International Journal of Research and Theory 1(1):67-92. https://doi.org/10.1080/14719037800000005

Koontz, T. M., and J. Newig. 2014. From planning to implementation: top-down and bottom-up approaches for collaborative watershed management. Policy Studies Journal 42(3):416-436. https://doi.org/10.1111/psj.12067

Kuenzer, C., V. Heimhuber, J. W. Day, O. Varis, T. Bucx, F. Renaud, G. Liu, V. Q. Tuan, T. Schlurmann, and W. Glamore. 2020. Profiling resilience and adaptation in mega deltas: a comparative assessment of the Mekong, Yellow, Yangtze, and Rhine deltas. Ocean and Coastal Management 198:105362. https://doi.org/10.1016/j.ocecoaman.2020.105362

Kuhn, D., T. Fickel, M. Rauchecker, D. Hummel, K. Brinkmann, S. Burkhart, F. Frick-Trzebitzky, T. Friedrich, and L. Nitschke. 2023. Natur im Konflikt: Konzeptualisierungen des Nichtmenschlichen in der Forschung zu Umweltkonflikten. ISOE-Diskussionspapiere 48. https://www.isoe.de/uploads/downloads/Publikationen/Reihen/ISOE-Diskussionspapiere/dp-48-isoe-2023.pdf

Lillebø, A. I., P. Stålnacke, and G. D. Gooch, editors. 2015. Coastal lagoons in Europe: integrated water resource strategies. International Water Association (IWA) Publishing, London, UK. https://doi.org/10.2166/9781780406299

Liski, A. H., P. Ambros, M. J. Metzger, K. A. Nicholas, A. M. W. Wilson, and T. Krause. 2019a. Governance and stakeholder perspectives of managed re-alignment: adapting to sea level rise in the Inner Forth estuary, Scotland. Regional Environmental Change 19(8):2231-2243. https://doi.org/10.1007/s10113-019-01505-8

Liski, A. H., M. J. Koetse, and M. J. Metzger. 2019b. Addressing awareness gaps in environmental valuation: choice experiments with citizens in the Inner Forth, Scotland. Regional Environmental Change 19(8):2217-2229. https://doi.org/10.1007/s10113-018-01458-4

Lonsdale, J.-A., C. Leach, D. Parsons, A. Barkwith, S. Manson, and M. Elliott. 2022. Managing estuaries under a changing climate: a case study of the Humber Estuary, UK. Environmental Science and Policy 134(1):75-84. https://doi.org/10.1016/j.envsci.2022.04.001

Lonsdale, J.-A., K. Weston, S. Barnard, S. J. Boyes, and M. Elliott. 2015. Integrating management tools and concepts to develop an estuarine planning support system: a case study of the Humber Estuary, Eastern England. Marine Pollution Bulletin 100(1):393-405. https://doi.org/10.1016/j.marpolbul.2015.08.017

Martinetto, P., D. Alemany, F. Botto, M. Mastrángelo, V. Falabella, E. M. Acha, G. Antó, A. Bianchi, C. Campagna, G. Cañete, P. Filippo, O. Iribarne, P. Laterra, P. Martínez, R. Negri, A. R. Piola, S. I. Romero, D. Santos, and M. Saraceno. 2020. Linking the scientific knowledge on marine frontal systems with ecosystem services. Ambio 49(2):541-556. https://doi.org/10.1007/s13280-019-01222-w

Newig, J., E. Challies, N. W. Jager, E. Kochskämper, and A. Adzersen. 2018. The environmental performance of participatory and collaborative governance: a framework of causal mechanisms. Policy Studies Journal 46(2):269-297. https://doi.org/10.1111/psj.12209

O’Toole, K., M. Keneley, and B. Coffey. 2013. The participatory logic of coastal management under the project state: insights from the Estuary Entrance Management Support System (EEMSS) in Victoria, Australia. Environmental Science and Policy 27:206-214. https://doi.org/10.1016/j.envsci.2012.12.011

Ostrom, E. 2009. A general framework for analyzing sustainability of social-ecological systems. Science 325(5939):419-422. https://doi.org/10.1126/science.1172133

Paalvast, P., and G. van der Velde. 2014. Long term anthropogenic changes and ecosystem service consequences in the northern part of the complex Rhine-Meuse estuarine system. Ocean and Coastal Management 92:50-64. https://doi.org/10.1016/j.ocecoaman.2014.02.005

Page, M. J., J. E. McKenzie, P. M. Bossuyt, I. Boutron, T. C. Hoffmann, C. D. Mulrow, L. Shamseer, J. M. Tetzlaff, E. A. Akl, S. E. Brennan, R. Chou, J. Glanville, J. M. Grimshaw, A. Hróbjartsson, M. M. Lalu, T. Li, E. W. Loder, E. Mayo-Wilson, S. McDonald, L. A. McGuinness, L. A. Stewart, J. Thomas, A. C. Tricco, V. A. Welch, P. Whiting, and D. Moher. 2021. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. Systematic Reviews 10(1):89. https://doi.org/10.1186/s13643-021-01626-4

Partelow, S., A. Schlüter, D. Armitage, M. Bavinck, K. Carlisle, R. L. Gruby, A. K. Hornidge, M. Le Tissier, J. B. Pittman, A. M. Song, L. P. Sousa, N. Văidianu, and K. van Assche. 2020. Environmental governance theories: a review and application to coastal systems. Ecology and Society 25(4):19. https://doi.org/10.5751/ES-12067-250419

Peirson, W., E. Davey, A. Jones, W. Hadwen, K. Bishop, M. Beger, S. Capon, P. Fairweather, B. Creese, T. F. Smith, L. Gray, and R. Tomlinson. 2015. Opportunistic management of estuaries under climate change: a new adaptive decision-making framework and its practical application. Journal of Environmental Management 163:214-223. https://doi.org/10.1016/j.jenvman.2015.08.021

Pinto, P. J., G. M. Kondolf, and P. L. R. Wong. 2018a. Adapting to sea level rise: emerging governance issues in the San Francisco Bay region. Environmental Science and Policy 90:28-37. https://doi.org/10.31230/osf.io/mjkcu

Pinto, P., R. Wong, J. Curley, R. Johnson, L. Xu, L. Materman, M. Avalon, G. Saraiva, A. Serra-Llobet, and G. M. Kondolf. 2018b. Managing floods in Mediterranean-climate urban catchments: experiences in the San Francisco Bay Area (California, USA) and the Tagus estuary (Portugal). Pages 93-133 in A. Serra-Llobet, editor. Managing flood risk. Innovative approaches from big floodplain rivers and urban streams. Palgrave Macmillan US, Cham, Switzerland. https://doi.org/10.1007/978-3-319-71673-2_5

Pinto, R., and J. C. Marques. 2015. Ecosystem services in estuarine systems: implications for management. Pages 319-341 in L. Chicharo, F. Müller, N. Fohrer, editors. Ecosystem services and river basin ecohydrology. Springer, Dordrecht, The Netherlands. https://doi.org/10.1007/978-94-017-9846-4_16

Rambonilaza, T., C. Boschet, and E. Brahic. 2015. Moving towards multilevel governance of wetland resources: local water organisations and institutional changes in France. Environment and Planning C: Government and Policy 33(2):393-411. https://doi.org/10.1068/c12299

Restemeyer, B., M. van den Brink, and J. Woltjer. 2019. Decentralized implementation of flood resilience measures—a blessing or a curse? Lessons from the Thames Estuary 2100 plan and the Royal Docks regeneration. Planning Practice and Research 34(1):62-83. https://doi.org/10.1080/02697459.2018.1546918

Root-Bernstein, M., and F. Frascaroli. 2016. Where the fish swim above the birds: configurations and challenges of wetland restoration in the Po Delta, Italy. Restoration Ecology 24(6):773-784. https://doi.org/10.1111/rec.12369

Rybczyk, J. M., J. W. Day, A. Yanez-Arancibia, and J. H. Cowan. 2012. Global climate change and estuarine systems. Pages 497-518 in J. W. Day, B. C. Crump, W. M. Kemp, A. Yáñez-Arancibia, editors. Estuarine ecology. Wiley, Hoboken, New Jersey, USA. https://doi.org/10.1002/9781118412787.ch20

Sayles, J. S. 2018. Effects of social-ecological scale mismatches on estuary restoration at the project and landscape level in Puget Sound, USA. Ecological Restoration 36(1):62-75. https://doi.org/10.3368/er.36.1.62

Sayles, J. S., and J. A. Baggio. 2017. Social-ecological network analysis of scale mismatches in estuary watershed restoration. Proceedings of the National Academy of Sciences 114(10):E1776-E1785. https://doi.org/10.1073/pnas.1604405114

Scarff, G., C. Fitzsimmons, and T. Gray. 2015. The new mode of marine planning in the UK: aspirations and challenges. Marine Policy 51:96-102. https://doi.org/10.1016/j.marpol.2014.07.026

Scott, T. 2015. Does collaboration make any difference? Linking collaborative governance to environmental outcomes. Journal of Policy Analysis and Management 34(3):537-566. https://doi.org/10.1002/pam.21836

Sousa, L. P., and F. L. Alves. 2020. A model to integrate ecosystem services into spatial planning: Ria de Aveiro coastal lagoon study. Ocean and Coastal Management 195:1-12. https://doi.org/10.1016/j.ocecoaman.2020.105280

Stepanova, O., and K. Bruckmeier. 2013. The relevance of environmental conflict research for coastal management. A review of concepts, approaches and methods with a focus on Europe. Ocean and Coastal Management 75:20-32. https://doi.org/10.1016/j.ocecoaman.2013.01.007

Stibbe, A. 2024. Ecolinguistics for ethical leadership. Pages 147-167 in S.-V. Steffensen, M. Döring, and S. J. Cowley, editors. Language as an ecological phenomenon: languaging and bioecologies in human–environmental relationships. Bloomsbury, London, UK. https://doi.org/10.5040/9781350304512.ch-007

Thomas, C. W., and T. M. Koontz. 2011. Research designs for evaluating the impact of community-based management on natural resource conservation. Journal of Natural Resources Policy Research 3(2):97-111. https://doi.org/10.1080/19390459.2011.557877

Truchet, D. M., B. M. Noceti, D. M. Villagran, and R. M. Truchet. 2022. Alternative conservation paradigms and ecological knowledge of small-scale artisanal fishers in a changing marine scenario in Argentina. Human Ecology 50(2):209-225. https://doi.org/10.1007/s10745-022-00309-5

Turner, R. K., M. G. Palmieri, and T. Luisetti. 2016. Lessons from the construction of a climate change adaptation plan: a Broads wetland case study. Integrated Environmental Assessment and Management 12(4):719-725. https://doi.org/10.1002/ieam.1774

Ulibarri, N., M. T. Imperial, S. Siddiki, and H. Henderson. 2023. Drivers and dynamics of collaborative governance in environmental management. Environmental Management 71(3):495-504. https://doi.org/10.1007/s00267-022-01769-7

Urlich, S. C., and J. L. Hodder-Swain. 2022. Untangling the Gordian knot: estuary survival under sea-level rise and catchment pollution requires a new policy and governance approach. New Zealand Journal of Marine and Freshwater Research 56(3):312-332. https://doi.org/10.1080/00288330.2022.2069131

van der Voorn, T., J. Quist, C. Pahl-Wostl, and M. Haasnoot. 2017. Envisioning robust climate change adaptation futures for coastal regions: a comparative evaluation of cases in three continents. Mitigation and Adaptation Strategies for Global Change 22(3):519-546. https://doi.org/10.1007/s11027-015-9686-4

Vanderlinden, J.-P., J. Baztan, N. Touili, I. O. Kane, B. Rulleau, P. D. Simal, L. Pietrantoni, G. Prati, and F. Zagonar. 2017. Coastal flooding, uncertainty and climate change: science as a solution to (mis)perceptions? A qualitative enquiry in three coastal European settings. Journal of Coastal Research 77:127-133. https://doi.org/10.2112/SI77-013.1

Voets, J., T. Brandsen, C. Koliba, and B. Verschuere. 2014. Oxford research encyclopedia of politics. Oxford University Press, New York, New York, USA.

Wang, W., and H. Gong. 2022. Formation mechanism of a coastal zone environment collaborative governance relationship: a qualitative comparative analysis based on fsQCA. International Journal of Environmental Research and Public Health 19(17):11081. https://doi.org/10.3390/ijerph191711081

Zaucha, J., S. Davoudi, A. Slob, G. Bouma, I. van Meerkerk, A. M. P. Oen, and G. D. Breedveld. 2016. State-of-the-lagoon reports as vehicles of cross-disciplinary integration. Integrated Environmental Assessment and Management 12(4):690-700. https://doi.org/10.1002/ieam.1802