Change and Continuity of Coastal Mangroves in Greater Mumbai, India: Towards the Sustainable Governance of Blue-Green Infrastructure

Abstract

In the coastal megacities of the Global South, where urbanization is steeply accelerating, it is a complex undertaking to navigate and govern for ecological sustainability while working to address mounting pressures to develop the physical and natural environment. In this study, we closely analyze the legality of coastal mangroves in Greater Mumbai through the lens of Blue-Green Infrastructure (BGI), sustainable governance, and environmental policy processes. While there is the constitutional and legislative protection of mangroves, they continue to disappear from the Greater Mumbai landscape, raising legitimate concerns about governance failures writ large. Using a mixed-method approach, we employ geospatial analysis of mangrove cover change from 1994 through to 2024, along with a thematic review of policy and institutional perspectives. The geospatial analysis indicated a −3.91% reduction in mangrove cover because of land-use developments, infrastructure encroachments, and the weak enforcement of existing regulations. The policy review identified limited regulatory coherence, institutional fragmentation, and low levels of community engagement. We advocate for the conservation of mangrove ecosystems in Mumbai, not just as an environmental resource, but also as vital urban infrastructure. We argue for the need to identify opportunities for reform, such as enhanced community contribution and participation, policy harmonization, and uniform incorporation of BGI principles into spatial planning and climate adaptation planning in Greater Mumbai.

1. Introduction

Mangroves are unique forms of vegetation that grow in intertidal zones and are largely restricted to the tropics and a few warm temperate regions between 30° N and 30° S latitudes [1]. The coverage of mangroves worldwide is 145,068 sq.km (as of 2020), of which nearly 40% is concentrated in Asia [2,3]. These intertidal forest ecosystems provide a great deal of ecological and socio-economic benefits. Mangroves serve as a buffer against storm surges, erosion, and flooding by dissipating wave energy and stabilizing the coasts [4,5]. Their thick root systems trap sediments and improve water quality, and they also act as vital carbon sinks to combat climate change [6,7]. Mangroves contribute to biodiversity as a habitat for a variety of aquatic and terrestrial species, and support local fisheries and livelihoods [8]. They generate ecosystem services that dovetail with nature-based solutions, mitigating the requirements for costly engineered defenses and improving urban environmental quality. In fact, natural ecosystem services are essential for meeting the human demands to fulfill the needs of sustainable development [9]. Despite providing such valuable services, mangroves are under increasing strain from coastal development, aquaculture expansion, pollution pressures, overharvesting, and climate change impacts such as sea-level rise and increased storm intensity [10]. It is estimated that we have lost about one-third of the global mangrove forests in the past 50 years [11].

The global value of mangroves arises from their multifunctionality. Mangrove forests are valuable for fisheries and migrating shorebirds, and are an integral part of disaster risk reduction [12,13], providing significant aspects of our global climate action commitments under the Paris Agreement [14], as well as our biodiversity commitments under the Kunming–Montreal Global Biodiversity Framework [15]. Thus, their effective protection and restoration not only benefit the environment at a local level but also enhance global environmental governance and sustainable development.

In the coastal megacities of the Global South, rapid urbanization, climate change, and ecosystem degradation have become significant challenges that necessitate swift and effective urban governance [16,17]. Blue-green infrastructure (BGI) offers a nature-based approach towards confronting these challenges by harmonizing ecological sustainability and urban resilience [18]. Hence, BGI has gained tremendous importance in recent years. Essentially designating a link between water bodies, or blue, and land systems that are vegetated, or green, BGI provides the most integrated approach to managing stormwater, biodiversity, climate adaptation, and improved urban living conditions, making it very different from conventional gray infrastructure, which primarily focuses on functionality [19,20]. The concept of BGI is rooted in landscape ecology and sustainable urbanism, aimed at reconnecting fragmented ecosystems in rapidly urbanizing regions [21].

Among the BGI, in coastal cities, there are wetlands, rivers, lakes, green corridors, urban forests, and coastal mangroves, a sensitive transition area between the land and the sea, which functions as a crucial protective barrier [22]. Coastal mangroves are, in fact, one of the most vital BGI systems encompassing an integrative mix of environmental and infrastructural functions that play a crucial role in developing urban sustainability and resilience [12,23]. Blue-green infrastructure (BGI) encourages the governance of sustainability through its view of ecological restoration responding to socio-economic vulnerability [24]. Existing research on the loss of mangroves is driven by land-use change from urban expansion, aquaculture, and agriculture, revealing widespread habitat loss and reduced ecosystem services [25,26,27]. Climate-induced sea-level rise and coastal erosion are increasingly threatening their existence [28,29]. Inclusion of BGI within policy attempts to create multi-functional, resilient landscapes and reflects the need for prudent adaptive planning [30].

In crowded coastal metropolises, where land-use pressures and climate risks are multiplying, mangroves can mitigate urban vulnerability to rising seas and severe weather by providing climate-adaptability measures [12]. Additionally, when incorporated in the context of urban planning, mangroves provide ecological connectivity, improving public access to natural sites, which supports social welfare and environmental justice [31]. The acknowledgment of mangroves as BGI serves to help progress beyond the static repository ideal of conservation, toward the active consideration of the imperative of integrating them in sustainable urban development and coastal governance [12].

The most urgent need for this study stems from the sudden loss and damage of coastal mangroves in the Global South, where Greater Mumbai serves as a prominent city regarding this problem. In this context, coastal mangroves form the thematic nexus, and in a metropolis like Mumbai, where a rapidly growing population has exacerbated urban development projects, have indeed posed threats to an already fragile coastal ecosystem, and hence it is paradoxically a place of both threats and opportunities. The ecosystem was once flourishing with mangroves stretching across Mumbai along the creeks and shorelines, but the huge development projects due to its exploding population have resulted in huge losses due to reclamation for land, infrastructural works, and pollution [32,33,34]. Mangroves are protected under legal regulations; however, due to indirect encroachment and fragmented policy implementations, they are quite vulnerable to human interventions as well as climate change-induced disasters [34]. Mumbai’s substantial loss of mangrove cover over the last few decades, despite constitutional and legislative protections, highlights the governance gaps and the need for more integrated and community-sensitive conservation strategies [35,36]. It is noteworthy that there has been a severe loss of mangrove cover in India over the last century, where the country has lost nearly 40% of its mangrove cover due to agriculture, aquaculture, urban development, and coastal modification [37].

The significance of this study is universal, as it contributes to understanding and dealing with the severe loss of coastal mangroves in a rapidly urbanizing area of the Global South, namely, Greater Mumbai. Such incidences of biodiversity loss are a common phenomenon in a majority of developing economies, and by using Mumbai as a case study, we hope its lessons can serve as examples to other developing countries of the world. The state of mangrove loss in this area reflects broader global patterns, where urban coastal ecosystems are undergoing damage due to reclamation, pollution, changed hydrology, as well as climate change. Thus, gaining insights from Greater Mumbai can inform integrated, community-centered conservation strategies applicable worldwide. This can contribute to sustainable urban resilience and the protection of vital blue-green infrastructure.

The main objectives of this study are the following: (i) analyze the changes undergone by the coastal mangroves of Mumbai; and (ii) examine how governance frameworks facilitate or hinder the conservation of the coastal mangroves.

2. Conceptual Framework and Theoretical Foundations

This research is situated at the intersection of environmental governance, urban sustainability, and ecosystem-based planning, drawing from three core theoretical pillars: BGI, sustainable governance, and policy and institutional frameworks for environmental conservation. Together, these conceptual lenses help construct a multidisciplinary framework to critically examine the conservation of coastal mangroves in Mumbai within the broader context of sustainable urban governance.

2.1. Theoretical Foundations of BGI

The idea of BGI comes from combining landscape ecology, urban planning, and hydrology. It combines vegetated landscaping (green) with hydrological functions (blue) to provide climate resilience and urban multifunctionality [38]. It is built on the notion that natural and semi-natural elements, like rivers, wetlands, forests, parks, and mangroves, can offer key ecosystem services to support urban sustainability when we keep them intact and connected [22]. BGI favors nature-based solutions (NbS) that adapt, serve multiple purposes, and stand up to ecological challenges, unlike traditional “gray” infrastructure that depends on engineered systems [39]. Landscape Urbanism stresses how ecological processes shape urban areas, suggesting that green and blue systems should form the basis of urban design, not just add to it [24,40]. For BGI, regulating services (such as flood control and climate regulation) matter a lot [41]. Resilience thinking pushes for urban systems that can adapt, have backup options, and stay flexible [42], the key features of BGI networks.

BGI serves as more than just physical infrastructure. It functions as a socio-ecological system woven into urban governance, calling for coordination across sectors, scales, and stakeholders [43]. In coastal cities such as Mumbai, mangroves stand out as BGI that provide multiple benefits, such as protecting the coast, storing carbon, providing clean water, and supporting biodiversity [44,45]. To preserve these assets, though, institutions need to acknowledge their value and align governance with broader urban development plans. However, from the perspective of environmental justice, the benefits of BGI are often not uniformly distributed. For instance, fishing communities, for whom mangroves mean livelihood security, storm protection, and cultural identity, are often not included in the formal governance of BGI [46,47]. This exclusion not only diminishes the social legitimation of conservation measures but also heightens socio-ecological vulnerability by taking away the communities’ traditional access rights and their participatory role in the co-management of the sustainable resources they rely on.

2.2. Theoretical Underpinnings of Sustainable Governance

The second theoretical basis of this study stems from the concept of sustainable governance. The concepts of sustainability and governance are inherently interconnected, and achieving sustainability typically depends on appropriate governance structures, which themselves must be designed to be sustainable over time [48]. It aims to be sound, fair, and viable in the long run. Sustainable governance focuses on balancing development and conservation in urban areas where resource demands are high. “Sustainability in the Anthropocene requires social cooperation and learning against a backdrop of increasingly complex, polycentric governance” [49]. Polycentric Governance argues that governance efforts are effective when no single center of decision-making is focal, even when these centers are operating at different scales [50,51]. This includes local bodies, forest departments, civil society, and communities when it comes to mangrove conservation. This approach encourages collaboration, shared accountability, and adaptive management, thereby balancing the need for mangrove conservation with the needs of development in urban coastal environments. Ultimately, this approach can help diverse actors collaborate, share information, and tackle issues as a collective to enhance resilience, legitimacy, and sustainability for the future of mangrove conservation in an era associated with complex socio-ecological dynamics typical of the Anthropocene.

Shifting from participatory to deliberative governance focuses on the importance of democratizing decision-making with which at the local level involves different stakeholders, especially people who suffer from environmental degradation [52,53]. Between the two, ‘adaptive governance’ emerges to represent the extent of governance systems’ learning and responding to feedback from the environment and capacity to evolve, in conditions of uncertainty, which are pertinent in the management of complex systems [54], as demonstrated by the urban mangroves under pressure from climate change impacts. Governing BGI should be not only environmentally conscious, but also reflexive as an institution [55], encompassing local knowledge systems to ensure sustainability [56]. The sustainable governance of BGI in urban areas calls for smart urban governance. Coastal and forest protection policies in India share synergies in biodiversity conservation, climate change mitigation, and supporting local livelihoods, especially through the legal safeguards for mangroves under both coastal regulation and forest conservation laws [57]. These frameworks can be made complementary using ecosystem-based management and community involvement [58,59]. That said, there are prioritized conflicts from boundaries in jurisdiction, imperfect governance, and different sectoral ambitions that leave limited capacity to coordinate their mandates for integrated approaches [60]. The existing system of smart governance in urban planning relies heavily on technocratic, data-driven decision-making, often overlooking local, context-specific knowledge and broader participatory processes, thereby reinforcing centralized bureaucratic structures rather than transforming them [61]. In Mumbai, urbanization and conservation are often pitted against one another, where governance systems often compromise with the aspect of sustainability [36].

2.3. Role of Policy and Institutional Frameworks in Environmental Conservation

The third principle of the conceptual framework emphasizes that there are policy instruments and institutional arrangements that affect the environment. Both in the design and implementation of policies, environmental priorities are largely articulated, operationalized, and enforced [62]. India has various policies and legal provisions established for the conservation of the coast and forests, such as the Coastal Regulation Zone (CRZ) Notification, 2011 [63], the Environment Protection Act (1986) [64], and the Forest Conservation Act (1980) [65]. However, the working of these frameworks largely depends on the coherence, transparency, and accountability of the institutional machinery [66]. For instance, the Coastal Road Project, despite being subject to CRZ regulations and Environmental Impact Assessments, went on to ignore them by reclaiming intertidal zoned land that threatened the mangrove ecosystem. This reflects on the inconsistency in the enforcement of policies [67,68]. Regulatory coherence demands policy consistency between environmental and sectoral (e.g., urban planning, infrastructure) objectives [69].

Institutional capacity and enforcement rule compliance, as well as monitoring, are important. The weak enforcement of mangrove protection is common in Mumbai [70]. The existence of overlapping jurisdictions and an inadequate capacity of municipal and state agencies results in limited action. Policy integration and mainstreaming to achieve sustainable results require the integration of environmental concerns into all stages of policy development, particularly land-use planning and the development of infrastructure [62]. Recent frameworks of Rights-Based Approaches emphasize the inclusion of environmental justice and community rights, particularly for indigenous communities and coastal people who rely on ecosystems such as mangroves [71]. Moreover, institutions serve not only as administrative mechanisms but also as normative and discursive arenas where interests are contested [72]. As such, environmental governance is also a political process, revealing power relationships, development paradigms, and societal norms [69].

The theoretical framework presented here provides a crucial foundation for understanding the conservation of coastal mangroves in Mumbai as more than just an environmental issue, but also as a governance problem within the broader conversation about BGI for sustainable urban futures.

3. Methodology

3.1. Study Area

Mumbai is India’s financial capital, a sprawling metropolis on the western coast of the Indian subcontinent. It includes the districts of Mumbai City and Mumbai Suburban (Figure 1). The geographical and ecological setting of the city makes it a unique study area to examine the interplay between urbanization, climate change, and coastal ecosystems, specifically mangroves. Mumbai lies along the Arabian Sea, with its coastline featuring several estuaries, creeks, and islands. The eastern edge of Thane Creek borders the city to the northeast, whereas the Vasai Creek serves as a boundary to its north, and on its southern side lies the Mahim Creek. The creeks of Rivers Mithi, Dahisar, and Poisar are part of essential rivers forming the hydrological system sustaining the mangroves in this area. Mangrove forests abound on the coasts and estuarine stretches in this city. It primarily has those along Thane Creek, Malad, Gorai, Mahim, and Versova [73]. The mangrove forests in Mumbai are some of the most important in India in terms of biodiversity and ecosystem services. The dominant species of mangroves in the city include the Avicennia marina and Rhizophora stylosa [74], which grow in the brackish waters of the creeks and estuaries of Greater Mumbai.

3.2. Data and Methods

We use mixed methods for completing this study, and these include (i) the GIS and Remote Sensing (RS)-based Spatial Assessment of the collected data; and (ii) Document Review and Thematic Analysis, as noted in the diagram below (Figure 2).

3.2.1. (i) GIS and Remote Sensing (RS)-Based Spatial Assessment

Geospatial techniques are employed to quantify and map changes in mangrove cover across two different temporal periods, i.e., 1994 and 2024. These years were chosen as temporal reference points to permit a clear long-term valuation of the net change in mangrove landcover over three decades from the pre-Coastal Regulation Zone enforcement conditions to the current conservation-oriented environment, an evaluation that uses years of comparable high-quality satellite imagery, which are less impacted by intermediate, short-term variations. The data for the study were acquired from the Landsat satellite images downloaded from the United States Geological Survey (USGS) Earth Explorer website. The satellite data is collected from two different datasets, where one of the sets comprises imageries from Landsat 5 TM (Bands 4, 3, 2), dated 4th March 1994, while the other set comprises imageries from Landsat 8 OLI (Bands 5, 4, 3), dated 11th February 2024. These datasets were chosen with consideration for their low cloud cover. The pre-processing and classification of the satellite data are carried out in the ArcGIS 10.8 software. The data is put through several pre-processing steps, such as rectification, layer stacking (Compositing Bands), and extracting the subset of the study area. The subsets of the study area derived for both years are extracted and converted to Standard False Color Composite (SFCC) images. For the classification process, supervised classification is applied using the Training Sample Manager, followed by Maximum Likelihood Classification to produce LULC maps for each year. To tackle spatial resolution limits, we carefully selected representative training samples to minimize classification errors. Finally, we calculated the area of mangrove cover class (along with the other classes) using both raster-based (Tabulate Area) and vector-based (Raster to Polygon with area field) methods. The classification is found to be acceptable based on the accuracy assessment methods applied to test its reliability (Supplementary File). The accuracy of the LULC classifications was assessed by generating random points in ArcMap and verifying them using Google Earth Pro. For the 1994 classification, a high accuracy of 91.0% and a Kappa index of 0.883 were found, indicating its reliability. Similarly, for the 2024 classification, a high accuracy of 93.0% and a Kappa index of 0.911 were found, validating its reliability. Thereafter, the change in Greater Mumbai’s Mangrove cover between 1994 and 2024 is detected. The mapping was completed by designing map layouts with essential cartographic elements such as legend, scale bar, north arrow, and title. Based on it, interpretations are made.

3.2.2. (ii) Document Review and Thematic Analysis

This study also uses the document review and thematic analysis approach to analyze the complexity of mangrove conservation in Greater Mumbai. We started with a review of secondary data sources, such as government reports, news articles, and peer-reviewed journal articles related to environmental governance and mangrove management in Greater Mumbai. These documents offer strong qualitative data insights into the policy development, implementation, institutional coordination, and governance issues. These data were then analyzed thematically by coding and inductively categorizing them to identify major patterns and policy gaps related to mangrove conservation. Major themes that came out in this analysis include the following:

Regulatory and Legal Frameworks as Enablers of Conservation;

Institutional Mechanisms and Technological Facilitation of Conservation;

Urbanization and Developmental Pressures as a Threat to Conservation;

Fragmentation and Ambiguity in Governance;

Gaps in Practical, Enforcement, and Community Engagement.

In the thematic analysis, we selected our documents through Google search using Boolean keyword searches (e.g., “mangrove*”, “Mumbai”, “governance”, AND “policy”). In this way, documents published between 2012 and 2025 were sourced from government portals, academic databases, and institutional repositories. Accordingly, at least 5 government reports, 5 peer-reviewed articles, and 5 gray literature sources addressing the themes were included. We made sure to exclude duplicates, unrelated works, and non-analytical items. The screening process involved title/abstract review and full-text analysis. We have analyzed the documents thematically by coding and inductively categorizing them to identify major patterns and policy gaps related to mangrove conservation. This thematic categorization is a narrative synthesis of literature, policy reports, and news sources. The literature used comprises published materials from 2012 to 2025, which are representative of current circumstances, policies, and case-specific data on Mumbai. In addition, there are significant references, which we provide as contextual legal, policy, and governance background, as well as a lesser representation of older but seminal works that serve as historical baselines on mangrove benefits. This is shown in the table below (

Table 1. Chronological distribution of key references and their thematic focus.

Year	Key References	Focus
2012–2014	[75,76]	Shows a strong focus on current institutional structures, urban projects, and recent mangrove cover changes
2017–2021	[36,77,78,79]	Provides governance, CRZ policy debates, and socio-environmental conflict background
2023–2025	[34,51,80,81,82]	Serve as historical benchmarks for legal rulings and ecological valuations
Undated	[83,84,85,86]	Serve as historical benchmarks for legal rulings and ecological valuations

).

Here, it is noteworthy that many times on the websites of the government agencies in India, we found the necessary information, but without any date of uploading or updating the information. In such cases, we have marked it as n.d., meaning ‘undated’.

The integration of spatial with thematic findings provides a full picture of the socio-ecological impact of mangrove loss and the current governance mechanisms in place.

4. Results

4.1. Status and Challenges of Coastal Mangroves in Mumbai: Change and Continuity, 1994–2024

Greater Mumbai’s mangroves are crucial natural buffers protecting the coasts and providing various ecosystem services, which help sustain and maintain the resilience of Mumbai’s ecosystem. However, based on the land cover classification carried out, we found that there has been a decrease in the mangrove cover of Mumbai between the years 1994 to 2024 (Figure 3A,B and Figure 4A,B). In 1994, the mangrove cover of Mumbai was 71.8 sq. km, which was reduced to 68.99 sq. km by 2024, hence an absolute loss of 2.81 sq. km and a percentage change in −3.91% (

Table 2. Change detection of mangrove cover between 1994 and 2024.

LULC Class	Area in Sq. Km (1994)	Area in Sq. Km (2024)	Absolute Change	% Change
Open Space	236.7609	198.0151	−38.7458	−16.37%
Built-up	71.7995	221.7717	+149.9722	+208.88%
Mangroves	71.8000	68.9900	−2.8100	−3.91%
Vegetation	67.4977	65.0000	−2.4977	−3.70%
Water Bodies	19.4174	19.4500	+0.0326	+0.17%

). The line graph (Figure 5) displays an uninterrupted decrease in mangrove cover in Greater Mumbai from 1994 to 2024, going from 71.8 sq. km to 68.99 sq. km. The linear regression suggests an average annual loss of around 0.0937 sq. km, supported by the linear regression equation (y = −0.0937x + 258.57) and the R-squared value of 1, depicting a perfect linear fit—even with only two observations.

4.2. Policy and Institutional Landscape

The political and institutional landscape surrounding the conservation of coastal mangroves in Mumbai can be categorized under the following five themes (

Table 3. Thematic table—governance and conservation of mangroves in Mumbai.

Theme	Description	Key Features	Implications
Theme 1: Regulatory and Legal Frameworks as Enablers of Conservation	Legal and policy instruments serve as the foundation for mangrove protection.	Environment Protection Act (1986), Forest Conservation Act (1980), CRZ Notifications—Bombay High Court ruling (2005) on protected status for mangroves by the government	Legitimizes conservation—Empowers judiciary and administration—Establishes mangroves as Ecologically Sensitive Areas
Theme 2: Institutional Mechanisms and Technological Facilitation of Conservation	Institutions and technology aid in governance, monitoring, and restoration efforts.	Maharashtra Coastal Zone Management Authority (MCZMA), Mangrove Cell, and Forest Department, GIS and Remote Sensing, Digital grievance redressal instruments—Mangrove App and online portals	Facilitates grassroots legitimacy—Supplements state capacity—Enables data-driven decision-making
Theme 3: Urbanization and Developmental Pressures as a Threat to Conservation	Development projects compete with ecological needs, often sidelining conservation.	Increasing population pressure, construction, and development activities, the Coastal Road Project, etc.	Highlights conflict between ecology and development—Reveals erosion of mangrove cover—Frames urban expansion as ecologically unsustainable
Theme 4: Fragmentation and Ambiguity in Governance	Multiple agencies create overlapping mandates and confusion.	Institutional ambiguity, governance complexity, overlapping jurisdictions, and rapidly blurring authority.	Delays in action and accountability—Blurred lines of authority—Weakens regulatory enforcement and ecological safeguards
Theme 5: Gaps in Practical, Enforcement, and Community Engagement	Weak enforcement, lack of planning integration, and exclusion of local actors undermine governance.	Poor integration of ecological data in planning—Insufficient compensatory afforestation—Marginalization of local communities/fishers	Social injustice in governance—Weak deterrence and poor compliance—Reduced resilience to environmental threats

), discussed below:

4.2.1. Theme 1: Regulatory and Legal Frameworks as Enablers of Conservation

The first key theme is regulatory frameworks as enabling ecological legitimacy for the conservation of mangroves. Articles 21, 47, 48A, and 51A(g) of the Constitution of India make it an obligatory responsibility of the State, along with its agencies and instrumentalities, to safeguard and conserve mangrove ecosystems [77]. Besides this, key legislation, such as the Environment Protection Act, 1986, CRZ notifications, etc., serve as platforms for designating mangroves as ecologically sensitive areas [77]. Judicial reinforcement, notably the Bombay High Court’s ruling in 2005 that designated mangroves occurring on government lands as protected forests, serves to further consolidate discourse and legitimize conservation efforts [75]. This theme highlights a legal framework as a motivating factor for protection and demonstrates how regulatory mandates legitimize environmental stewardship.

4.2.2. Theme 2: Institutional Mechanisms and Technological Facilitation of Conservation

In Mumbai, mangrove conservation practices depend on a combination of institutional mechanisms and technological tools. Institutions include existing regulatory and statutory authorities like the Maharashtra Coastal Zone Management Authority (MCZMA) [83], Mangrove Cell [84], and the Forest Department [85] that help enforce mangrove protection resources and develop enforcement [78]. Technologies such as GIS and Remote Sensing are used for mapping the mangrove cover and monitoring encroachments [80]. Digital grievance redressal instruments, such as the Mangrove App and online portals for environmental clearance applications, also exist [86]. These institutional and technological engagements offer greater transparency, evidence-based decision-making, and community engagement in conserving Mumbai coastal ecosystems.

4.2.3. Theme 3: Urbanization and Developmental Pressures as a Threat to Conservation

A clear counter-narrative is the progressive incursion of urban development into mangrove ecosystems. As per a study, Mumbai has experienced a loss of approximately 40% of its mangrove cover from 2004 to 2014 [76]. This decline is primarily attributed to increasing population pressure, construction and development activities, the conversion of land for agricultural purposes and fish farming, as well as the impact of industrial effluents [34,51,76]. In addition, the Coastal Road Project is estimated to affect 8.2 hectares of mangrove area [81]. It reveals the conflicting priorities of environmental conservation laws and coastal development, as it seeks to position the city’s urban future explicitly in conflict with ecological sustainability.

4.2.4. Theme 4: Fragmentation and Ambiguity in Governance

There exists fragmentation with respect to environmental governance. Multiple agencies are exhibiting their own versions of remitted authority with respect to disparate components of mangrove management, but none coordinate on areas of complementary action, and they act in both separate and simultaneous ways [82]. It is not just an institutional ambiguity, but a governance complexity that reveals overlapping jurisdictions and rapidly blurring authority when faced with a time-sensitive environmental crisis. The latest CRZ regulation emerged as a violation of the earlier regulation, weakening the implementation of CRZ norms greatly by eroding safeguards it had previously designed to uphold, but it also privileges developmental considerations further into the coastal context [79].

4.2.5. Theme 5: Gaps in Practical, Enforcement, and Community Engagement

The conservation of mangroves in Greater Mumbai encounters significant gaps in practice, enforcement, and community involvement. There are practical shortfalls in execution around monitoring, responding to encroachments on time, and funding for on-ground action. Community involvement is also weak and often limited to awareness campaigns, so long-term commitment is typically limited. Furthermore, local communities and artisanal fishers are typically excluded from processes of governance, creating mistrust and further marginalization and inequity [36]. These gaps in practice and policy undercut ecological resilience and reduce the collective ability to protect mangroves from rapid urbanization and development pressures along the city’s vulnerable coastline. However, the sustained independent stewardship of the mangroves in Vikhroli by the Godrej Group is noteworthy in this regard, highlighting how the private sector has effectively contributed to the conservation of large tracts of urban mangrove forests in Greater Mumbai over four decades [87]. Fisherfolk helped in this initiative by sharing their knowledge about tide cycles, sediment shifting, and fish migration, and in return, participated in species documentation by adding local names to the mangrove app [87].

5. Discussion

Our study describes a very complex and interactive relationship between urbanization, fragmented governance, and sustainable coastal blue-green infrastructure, namely, mangrove ecosystems, in an urbanized context. This study’s findings reveal that the existing nature of urban pressures, in conjunction with weak policy mandates, risks compromising both the ecological integrity and governance of BGI in Mumbai. Also, while the loss of mangroves over the past 30 years appears minimal at first glance, a deeper insight reveals its ecologically significant negative impacts, especially considering the ecosystem services provided by the mangroves to Greater Mumbai [76].

As highlighted by the global literature, mangroves provide many ecosystem services such as shoreline protection, carbon storage, and habitat for biodiversity, making them a key element of coastal BGI, so the loss of even small areas can have disproportionate ecological effects and reduce resilience to storms and sea-level rise [2,88,89]. More broadly, loss of mangrove exacerbates the challenges to urban resilience from climate change and sea level rise [90]. This decay of mangrove can be attributed to both anthropogenic (urbanization, encroachments) and natural (climatic) factors [34]. In the global context, it has been found that while mangrove loss has slowed in certain regions, land-use changes related to coastal development and urban expansion continue to be a leading driver of loss, which aligns with our observations of stressors associated with urbanization in Mumbai [91].

Mumbai’s urban expansion has always outpaced its population growth [92]. Mumbai has witnessed exceptional urban growth in a very short period [51]. Its urban growth is a constantly ongoing process, which exacerbates the suffering and the degradation of its natural environment due to uncontrolled and exploitative urban development. However, the nature and pace of urbanization have varied across Mumbai. The urban expansion in the coastal areas of Mumbai has always differed from the inland areas, given the premium values of coastal lands [92]. The coastal areas took the form of edge expansion, while the inland areas underwent infilling [92]. The width of Mumbai’s creeks has been reduced by the impact of urbanization [93]. In addition, Mumbai’s Coastal Regulation Zone (CRZ) rules have also been violated severely. According to one study, spillovers from urban development have led to navigation patterns and unnatural tidal flows, as narrow creeks are being reclaimed, directly impacting mangrove health. This is because flooding and water flow are premised on maximizing the area of the overall mangrove ecosystem [34,93]. Global assessments reveal threshold rates above which many mangrove species are not able to vertically accrete enough to keep pace, thereby suggesting that the risk is elevated where landward migration is constrained by development, typically in large coastal cities [94,95]. These international trends align with our finding that macro-level losses, although low in absolute numbers, are significant from an ecological perspective, likely due to the high density of urban growth as in Greater Mumbai.

Urban systems are assets for climate change and have significant exposure to climate hazards; planning with nature-based solutions such as mangroves is widely recognized as both a mitigation and adaptation strategy in cities globally [96]. Combined, coastal regulatory zone (CRZ) violations around abandonment, reclamation, and STPs signal why land-use governance is a consistent failure in Mumbai [36]. This violation has led to rapid urbanization on the one hand and the consequent destruction of mangroves, wetlands, coastal ecology, and urban biodiversity on the other [35,36]. The decrease in mangroves in Mumbai is largely due to the growing population pressure, construction and development activities, land-use change, etc. [93]. Thus, the urbanization of Mumbai has been detrimental to its mangrove vegetation.

Adding yet one more crucial layer of complexity to sustainable BGI governance is climate change. Mumbai, being a coastal city, is threatened by sea level rise, [97], as seen in the case of many other coastal cities of the world [98]. This has especially become a grave concern for Mumbai due to the fast pace of its urbanization. Existing research suggests that urbanization contributes significantly to climate change [99], which, in turn, is a driving force behind sea level rise [98]. As one of the worst-affected cities of the world, Mumbai faces the dire consequences of sea level rise [100]. The recorded sea level rise in Mumbai is approximately 3 cm per decade [101]. This gradual but steady rise in sea levels poses a serious threat to the city’s coastal ecosystem. A key aspect of this threat is the impact on Mumbai’s mangrove forests, which are ecologically significant for the city. Most mangrove species in Mumbai’s wetlands are unlikely to survive the rising sea levels [102]. Thus, the mangrove ecosystem of Mumbai is facing a severe threat from sea level rise.

From a policy and governance perspective, the study also presents relevant aspects. While environmental regulations and judgments like the Environment Protection Act (1986) and CRZ Notifications can offer legal scaffolding around mangrove protection [77], they lack enforceability and are often reactive to environmental stresses [103]. For example, the verdict from the Bombay High Court in 2005, declaring mangroves on government land as protected forests, legitimized decades of conservation efforts in Mumbai [75]; however, the legal enforcement of these policies is lacking. In mangrove governance, institutional fragmentation often reflects the competing priorities of urban development and conservation perspectives [104,105]. In Mumbai, infrastructure, housing, and transport agencies are often directed by mandates that serve as competitors to environmental and coastal regulatory agencies. Confused jurisdictions and competing policy directives further exacerbate this tension and produce delays, contradictory compliance instructions, and ineffectual enforcement.

Institutions like the Mangrove Cell, MCZMA, and MFD functions are undertaking overlapping mandates with limited coordination, often resulting in regulatory confusion, bureaucratic inertia, and accountability gaps. Without any coherence in strategy for integration, the institutional structures do not fully deliver integrated BGI governance [82]. In addition, recent amendments to the CRZ norms (primarily the 2019 notification) have eroded the previously established safeguards for mangroves and embedded a policy bias toward further urban development [79], which undermines the regulatory functions of state actors in protecting mangrove values. International evidence indicates that we must move away from reactive, top-down regulation to polycentric, participatory arrangements that engage local communities in decision-making and co-management as a way to recognize local knowledge protocols and processing in more adaptive ways [46]. These approaches have been shown to lower anthropogenic stressors and improve stewardship in mangrove reserves [46].

Technological developments in environmental monitoring, whether GIS systems, drone surveillance, or mobile applications such as the Mangrove App, are technologically inspiring for data-driven governance and offer “new” public governance opportunities [80,86]. However, the availability of digital tools and institutional mechanisms does not guarantee purposeful outcomes unless there are resources (i.e., staffing, funding, and multi-institutional collaboration) [78]. This study finds that there are operational constraints that dominate any potential of allowing such innovations to have any real-world functionality. While these new monitoring technologies have the potential to enhance compliance and adaptive management, global studies have shown that monitoring must be embedded in institutional capacity and funding, and inter-agency coordination [106]. This reinforces our finding that operational constraints limit the functionality of new technologies in the real world. At the same time, the loss of mangroves makes natural coastal protection weaker or less effective, causing cities to invest massive sums into expensive gray infrastructure, such as seawalls and embankments [107]. Existing studies show that mangroves reduce annual flood damage by huge sums globally, while their degradation significantly increases infrastructure costs [108]. Cities prioritizing blue-green infrastructure (BGI) within their planning procedures ensure savings from restoration costs rather than concrete or stone defenses [108]. BGI can be an integrated effort to protect coastlines, promote public cost savings, and improve longer-term local resilience against climate-related hazards.

6. Conclusions and Future Directions

This study identifies the change in mangrove cover of Greater Mumbai within three decades to contribute to the discussion on mangrove conservation within the context of blue-green infrastructure governance. We explore aspects of CRZ infractions and policy changes, uncovering spatial pressures, governance contradictions, and the limited inclusion of marginal communities in the context of the decrease undergone by the mangrove cover of the area. The constraints of resource availability, stakeholder engagement, and data continuity challenged the study and restricted bringing to light micro-level analysis. Nevertheless, the study presents a strong macro-level analysis of conservation practices and governance shortfalls.

This study reveals that Mumbai’s mangroves are at a critical juncture, legally and ecologically, holding their ground overall, yet facing intense, localized threats that require sustained, multi-pronged governance, scientific, and community-focused responses. While Mumbai has a governance architecture dedicated to mangrove conservation, its effectiveness is limited by the pull of competing developmental agendas, fragmented institutions, and exclusionary planning practices. Although there are legal mandates and enforcement mechanisms for mangrove governance, what is evident or required is a step toward integrated planning and inclusive, ecologically aware urban governance, much less the reduction in the city’s aspirations to tame the environment in the name of development. Most conservation actions are still taken from the top down, with minimal input from coastal communities or artisanal fishers, who are both stewards of mangrove ecosystems and stakeholders in the management of the coastal area. Hence, Greater Mumbai’s mangrove conservation requires a move from sectoral and reactive governance to sustainable, adaptive, and participatory governance.

To apply BGI principles in the spatial-planning process and its regulatory framework, municipal and state planning authorities must encourage planners to put mangrove conservation zones and ecological buffers, and blue-green corridors, within Development Plans, Coastal Zone Management Plans, and climate resilience plans. Improved land-use policies, together with strict zoning and restoration requirements and community participation, can help regulate encroachment and set the stage for both urban growth and mangroves to co-exist over the long term. For this, planners must use spatial-planning tools that prioritize ecosystem services to protect biodiversity, along with inevitable urban infrastructure aids, and legal instruments to ensure that BGI plans are interpreted as critical infrastructure at par with transport or housing needs. To apply and formalize community engagement within governance arrangements, environmental authorities must formally embed the representation of coastal communities, especially underrepresented groups, such as fishers and women, into mangrove management committees, environmental clearance processes, and monitoring and mapping disaster-risk reduction planning processes.

Communities can establish permanent co-management platforms, community-led monitoring programs, and even benefit-sharing methods to align ecosystem outcomes and social and economic livelihoods. Additionally, ensuring regular engagement with local policy networks and anchoring sustainability principles into the long-term preservation of the urban ecosystem can strengthen local policy engagement, foster long-term stewardship, and create climate-resilient urban systems in which BGI can emerge as a foundational principle of Mumbai’s spatial and socio-economic development. Furthermore, using reference from a study on Chengdu’s multifunctional cycling greenways, we can use data-driven models to inform the place-based planning of mangrove conservation that links mobility, recreation, and greenway ecological protection [109]. Similarly, integrated mangrove management can utilize spatial analytics and multifunctional design strategies to ensure that urban development and the delivery of ecosystem services are harmonized, thereby offering sustainable outcomes in the use of blue-green infrastructure.

To address the governance–technology gap, it is essential to establish a coherent polycentric governance structure that facilitates decentralized decision-making and interconnected, multi-institutional governance, incorporating community participatory monitoring. Combining forms of local ecological knowledge, such as those from fishing communities, with technological information can facilitate adaptive co-management that is both accountable and legitimate. Evidence from across the globe shows that multi-actor approaches like these can reduce human pressures, improve mangrove stewardship, and provide a practice for utilizing technological potential with limited institutional capacity [110]. Considering the overlapping jurisdictions and competing directives, we recommend an inter-institutional coordination mechanism that combines transparent roles and responsibilities with a collective planning process to intentionally integrate conservation priorities in development proposals at an early stage. The development of time-bound action plans and clear performance indicators can support accountability, organize conflict resolution, and help balance development and conservation objectives transparently.

This study has its limitations, but it also highlights important research directions. First, a reliance on secondary data limited the ability to represent lived experiences and informal governance processes. Future research should incorporate field-based case studies, interviews with multi-stakeholders, and participatory mapping with coastal communities to build more contextually specific information and empirically validate institutional analyses. Second, the nature of the study obstructed identifying rapid changes over short timescales. For future research, we would suggest using high-frequency remote sensing, Unmanned Aerial Vehicle (UAV) surveys, or citizen-science-based ecological monitoring to obtain this temporal resolution. Third, the study provides a macro-level policy analysis, but we have no information about micro-level socio-ecological processes in the study areas. Future studies could comprehensively collect mixed-method data, including household surveys, ethnographic methods, and spatial analyses, to assess how conservation policies and practices developed in relation to community experiences in the ‘real’ world.