ABSTRACT
Our Earth has given many ecosystems that will heal themselves from the degradations. One of those ecosystems is the wetland, which is a precious natural sponge, naturally purifying and replenishing the water, heading off floods, and mainly giving tremendous biodiversity to the flora and fauna. However, human activities are degrading the wetlands and polluting them indiscriminately with solid wastes and domestic and industrial wastewater discharge. With the Ramsar Convention on Wetlands, nations around the world have acknowledged the critical benefits of wetland restoration and development. In this review article, we contributed to address the general wetland policies in the world, both nationally (India) and regionally (Tamil Nadu). In this paper, we will be discussing the reviews on the characteristics of wetland ecosystems, indices of biodiversity, risks to the wetland's restoration tactics, its main obstacle, and the financial advantages of wetlands. After clearly analyzing 226 previous research and review articles, a clear coherence between the explored hypothesis of wetland restoration mechanisms and the resulting economic and social benefits was arrived. Our findings indicate that effective restoration not only enhances ecosystem services but also leads to significant economic gains and improved community well-being. This alignment underscores the importance of investing in wetland restoration for sustainable development.
HIGHLIGHTS
Wetlands ecosystems influence climate change.
Human activities are degrading the wetlands and polluting them indiscriminately.
Wastewater discharge in wetlands is a regular phenomenon.
We contributed to address the general wetland policies in the global, national (India), and regional (Tamil Nadu) level.
INTRODUCTION
Wetlands, which include bogs, marshes, and swamps, are essential habitats that are defined by the presence of water (Mitsch & Gosselink 2015). Ecologically, they support a rich biodiversity, providing habitat for numerous plant and animal species crucial for global biodiversity (MEA 2005). Socially, wetlands offer recreational opportunities and cultural significance, serving as venues for birdwatching, fishing, and traditional practices (MEA 2005). Economically, wetlands contribute to livelihoods through activities such as fisheries, agriculture, and tourism, generating income and supporting local economies (Barbier et al. 1997). In addition, they play a vital role in water purification, flood regulation, and carbon sequestration, providing essential ecosystem services that benefit both nature and society (Zedler & Kercher 2005). Currently, there are more than 2,400 Ramsar Sites worldwide. They cover an area of over 2.5 million km2, which is larger than Mexico (Ramsar Convention on Wetlands 2018). Wetlands are home to a third or more of all threatened and endangered species. Wetland management strategies involve legal protections and restoration projects to conserve and enhance ecosystem functions while promoting sustainable use and involving local communities to balance ecological health with human needs. After all, the constant monitoring of the functions is the most important thing to retain its natural form. Many publishers are facing issues related to ecological restoration, cutting-edge technology, and policies since new technologies necessitate the use of novel approaches (Wei et al. 2023). Globally, wetlands have been degraded by about 35% since 1970 (Darrah et al. 2019; Let & Pal 2023). Worldwide up to 90% of the wetlands are considered as most threatened and demolished due to illegal land reclamations, encroachments, and pollution (Abramovitz 1996; Casazza et al. 2021).
As per the United Nations (UN) Millennium Ecosystem Assessment (2005), compared to other natural ecosystems, wetlands are the most degraded system in our earth (Murali 2021). Agenda 15 for 2030 (Sustainable Development Goal (SDG)15) of the UN outlines the objectives of stopping and reversing land degradation, stopping biodiversity loss, combating desertification, protecting, restoring, and promoting sustainable use of terrestrial ecosystems. Most of the literature studies have shown the impacts of socioecological aspects on the wetlands globally (Barbier et al. 1997; MEA 2005; Zedler & Kercher 2005). There is still a need for increased public awareness of environmental monitoring, sophisticated instruments, and data to be able to stop the loss of wetland habitat (Darrah et al. 2019). Though some unique wetlands have been recognized as Ramsar sites, people are not aware of the wetlands and their ecosystem functioning, and still, many wetlands are considered wastelands and getting polluted and degraded. According to Kexin et al. (2022), wetlands' degradation areas are divided or named into some classifications such as undegraded, lightly degraded, moderately degraded, and extremely degraded. Nearly some indicators were denoted from three main factors: hydrology indicators, soil indicators, and biota indicators (Fennessy et al. 2007). These factors are the main indicators for the well-function analysis of the wetlands (Barbier et al. 1997).
Due to a lack of vulnerability assessments, many wetlands in India are still unrecognized by the local population. The wetlands provide an important environmental resource by regulating the climates and giving opportunities for some benefits like fishing, irrigation, and some recreation (Engelhardt & Ritchie 2001; Adekola & Mitchell 2011; Malekmohammadi & Jahanishakib 2017). A framework for the assessment of wetland ecological risk has been presented by Duan et al. (2022). It includes factors related to abiotic characteristics for both internal and external hazards. Many ecological restoration solutions have been tried and implemented in the last 10 years, but there are still some gaps in the systematic planning, problem-solving after the restoration is successful, and overall process of the study that needs to be identified and investigated. The main challenge for wetland managers is clinching of long-term sustainability through the securing of wetlands ecological values against the socioecological activities (Pirali Zefrehei et al. 2022).
Ecosystem services of wetlands (Source: Tamil Nadu Wetland Mission).
The objective of this review is to explore various wetland restoration mechanisms and evaluate their economic and social benefits. It aims to highlight how effective restoration can enhance ecosystem services and support sustainable community development.
WETLAND POLICIES
Global level policies
Global wetland policies are crucial frameworks for protecting and maintaining these important ecosystems, which offer crucial services including preventing flooding, removing pollutants from water, and preserving biodiversity. The cornerstone of global efforts to conserve wetlands is the Ramsar Convention, which was created in 1971 and encourages the prudent use and sustainable management of wetlands everywhere (Ramsar Convention Secretariat). The Convention encourages member countries to designate Ramsar sites wetlands of international importance and implement measures to protect and restore them. Furthermore, as a crucial component of global environmental management, the 1992 Convention on Biological Diversity (CBD) highlights the preservation and sustainable use of biodiversity, including wetlands. CBD member countries commit to integrating biodiversity considerations into national policies and promoting ecosystem resilience, crucial for wetland ecosystems facing threats from climate change and human activities.
In this world, many people depend on wetlands and rivers for their daily livelihoods (Ramsar 2018; CIFOR 2021; Nygren & Lounela 2023), which will affect the natural balance. The UN Environment Programme Executive Director claims that fast degradation and loss of wetlands worldwide is caused by policies and actions that frequently fail to take into account the multitude of functions that wetlands offer (UNEP State of Finance for Nature Report 2023). In light of the warnings issued by international scientists that biodiversity loss, ecosystem degradation, and climate destabilization all exacerbate wetland loss, which represents a global emergency, new strategies are required to ensure that wetlands are protected and that their benefits to people are sustained (Davies et al. 2020). People from the United States started to recognize that the wetlands had plenty of benefits among the other natures (Votteler & Muir 2002). Some of the management practices applied to wetlands by the Conservation Foundation is shown in Table 1.
The management practices applied to wetlands
Physical way . | Chemical way . | Biological way . |
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Physical way . | Chemical way . | Biological way . |
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Source:Votteler & Muir (2002).
Section 404 of the US Environment Protection Act (US EPA) controls the discharge of dredged or fill material, which is classed as a pollutant, into US waterways by requiring potential dischargers to obtain a permit for such actions (Ainslie 1994). According to a study of wetland mitigation methods in eight states, more wetland acreage was lost in the USA than was required to be created or restored, resulting in a net loss of acreage when mitigation was included in a wetlands permit (Kentula et al. 1992). In the past 300 years, Canada has faced terrific wetland loss (Austen & Hanson 2007) and without rules, individuals working for government agencies are left to use their best judgment, which results in inconsistent policy application (Farnese & Belcher 2006; Austen & Hanson 2007). Canada's policy goals are to maintain the biological and socioeconomic systems for the time being and to encourage the preservation of wetlands in the country going forward (Austen & Hanson 2007). The ‘Wetland Protection Law’ (WPL) was enacted on 24 December 2021, following three National People's Congress discussions, and it went into effect on 1 June 2022 with Wetland restoration, supervision, inspection, and legal obligations, as well as the preservation and use of wetland resources (Mo et al. 2023). Ahmed & Haque (2023) analyzed the effects of Bangladesh's wetland management and policy on the rights and means of subsistence of nearby wetland-dependent populations. Nongovernmental organizations (NGOs), Indigenous people, and local communities have worked to recognize the rights of nature; on occasion, courts, local and national legislatures, and international organizations have also provided support (La Follette & Maser 2020).
Recognizing wetlands is made possible by a special wetland policy. Other sectoral management objectives do not cover ecosystems and require specific management and conservation measures (Ramsar 2010). Capitalism is a method of growth in which economic benefits and commercialism are emphasized over wetland preservation and management (NUWAGABA 2023). Sectoral objectives for wetland management increasingly reflect the UN's inclusive requirements for sustainable development agendas. These goals are in line with the SDGs, especially those concerning life below water (SDG 14), life on land (SDG 15), and clean water and sanitation (SDG 6). They also make sure that social justice, ecological preservation, and economic viability are incorporated into management practices (Ramsar 2010).
Wetland policies in India
The primary legislative framework for wetland protection in India includes The National Plan for Conservation of Aquatic Ecosystems, the Ramsar Convention, the Wetlands (Conservation & Management) Rules (2017), and the National Wetland Inventory and Assessment (NWIA). Wetlands Rules (2017) rules provide guidelines for identifying and notifying wetlands, restricting certain activities, and empowering state governments to manage and protect wetlands (Sinha & Mohanty 2002). The rules also set up a Central Wetlands Regulatory Authority and State Wetlands Authorities. These rules emphasize involving local communities in wetland management, recognizing the traditional knowledge and practices that support sustainable wetland use. The NWIA program, funded by ISRO, provides a scientific basis for wetland management (Attri 2017). These data aid in the formulation of management plans and monitoring efforts. India's commitment to the Ramsar Convention reflects its dedication to international standards of wetland conservation. The designation of Ramsar sites helps attract global attention and funding for wetland conservation (Prasad et al. 2002). Despite these robust frameworks, several challenges persist. The effectiveness of policies often varies due to differences in state-level execution and monitoring capacities (Devabalane 2015). Rapid urbanization, industrial activities, and agricultural runoff contribute to wetland degradation. Public awareness and involvement in wetland conservation are often limited, affecting community participation.
The EPA 1986, in India, plays a crucial role in wetland conservation by empowering the government to enforce regulations against pollution and habitat destruction. It facilitates formulating and implementing policies aimed at preserving wetland ecosystems and maintaining their ecological balance. This Act underscores the importance of protecting wetlands for environmental and socioeconomic benefits. In India, the National Forest Commission stressed the significance of protecting wetlands as essential parts of forest ecosystems. It recommended integrated management practices and stricter regulations to protect wetlands from degradation and encroachment. These recommendations have been pivotal in shaping policies for wetland conservation in India (National Forest Commission, 2006). The National Environment Policy 2006 in India underscores the need for wetland conservation to maintain ecological balance and support biodiversity. It advocates for sustainable management practices, legal protection, and community involvement in wetland preservation. The strategy offers a thorough framework for addressing risks and encouraging wetland restoration (MoEF 2006). In India, the National Policy and Macro Level Action Strategy on Biodiversity (1999) aims to conserve biological diversity through sustainable use and equitable sharing of benefits (MoEF 2006). It emphasizes the protection of natural habitats, including wetlands, and integrates biodiversity considerations into sectoral planning (MoEF 2006). A strategic framework for national biodiversity protection is provided by this policy.
To safeguard marine resources, foreign vessels' fishing operations in India's exclusive economic zone are governed by the Maritime Zones of India (Regulation of Fishing by Foreign Vessels, Act 1981). It establishes guidelines and restrictions to prevent overfishing and ensure sustainable exploitation of marine life. This act is crucial for conserving India's maritime biodiversity and ensuring national jurisdiction over marine resources. The Territorial Waters Continental Shelf Exclusive Economic Zone & Other Maritime Zones Act (1976) defines India's maritime boundaries and regulates the use of marine resources. To explore, exploit, and conserve marine resources, it gives India sovereign powers over its exclusive economic zone, continental shelf, and territorial waters. This Act is fundamental for managing India's maritime jurisdiction and protecting its marine environment. In India, the Wildlife (Protection) Amendment Act (2022) strengthened the measures for wildlife conservation by enhancing penalties for offenses and expanding protected areas. It aimed to combat wildlife crime and regulate trade in endangered species more effectively. This amendment significantly contributed to the preservation of India's diverse wildlife heritage.
India, like the USA, has a robust regulatory framework, but enforcement and compliance remain challenging. The EU's integrated approach could serve as a model for better coordination across different sectors. India's emphasis on community participation is notable, aligning with Australia's approach, but more efforts are needed to enhance local engagement. India's use of remote sensing and GIS technologies is on par with global practices, yet the application of these data for effective management needs improvement. India's active participation in the Ramsar Convention is commendable, similar to practices in Australia and the EU.
ATTRIBUTES OF WETLANDS – INDICATORS
Wetlands are vital ecosystems characterized by attributes such as hydrology, soil type, and vegetation, which serve as key indicators of their health and functionality. Hydrology, the presence and movement of water, is crucial for sustaining wetland ecosystems (Mitsch & Gosselink 2015). Soil type, often hydric soils, indicates prolonged saturation and supports wetland plant species (USDA NRCS 2010). Vegetation, including hydrophytic plants, provides habitat, stabilizes soil, and contributes to water quality (Tiner 1999). These indicators collectively help assess wetland conditions and guide conservation efforts.
Hydrological indicators
As the wetlands are interconnected with the biotic and abiotic factors together, the hydrological connectivity with the wetland is more important. Billah et al. (2022) have found more than 200 indicators that provide the complex of biodiversity in the Salt Marsh. The ‘Ecological Character’ of wetlands and the ‘Wise Use’ notion are specified by the Ramsar Convention, suggesting that wetland ecosystem services may be utilized to some degree. There has been lot of research on hydrological indicators to study the wetland (Table 2).
Hydrological indicators and the successful methods/technologies
S. No . | Hydrological indicators . | Methods/technologies . | References . |
---|---|---|---|
1. | Water salinity, water depth, water temperature, salt marsh diversity, soil water content, soil redox, soil conductivity, soil organic matter, sediment texture, soil bulk density, soil conductivity, soil pH, soil salinity, pore water salinity, soil organic matter | – | Billah et al. (2022) |
2. | Wetland depth, consistency in water appearance, stability of hydrology, eco deficit, and failure | Remote sensing (NDWI, MNDWI – range of variability approach and flow duration curve methods, FDC curve, range of variability approach (RVA) approach) | Pal & Sarda (2020) |
3. | Land–water threshold dynamics, hydro-potential zones, hydro-geomorphic dynamics, hydro-period, and water presence frequency | The satellite imagery based remote sensing indices (NDWI and NDVI have been calculated using the Landsat imageries, MNND) | Mukherjee & Pal (2021) |
4. | Land–water threshold dynamics, hydro-potential zones, hydro-geomorphic dynamics, hydro-period, and water presence frequency | The satellite imagery based remote sensing indices (NDWI and NDVI have been calculated using the Landsat imageries, MNND) | Mukherje & Pal (2021) |
5. | Hydrological variability | Time series remote sensing data (image-based hydrological attributes integration, histogram comparison approach (HCA), RVA) | Pal & Sarda (2021) |
6. | Net wetness and water depth wetness over a period Shoreline dynamics | NDWI Theil–Sen estimator slope hydrogeomorphic (HGM) | Singh & Sinha (2021) |
7. | Index of hydrological connectivity (IHC), root parameters, and soil properties | Field dye-tracing experiments, back propagation (BP) neural networks, global sensitivity and uncertainty analyses, and statistical analysis | Zhang et al. (2021) |
8. | Hydro-period, water presence frequency, water depth calculation | Time series Satellite Images – Landsat | Khatun et al. (2021) |
10. | Hydrological connectivity composite index (average annual precipitation, artificial influence rate, water area rate) | LANDSAT – (eCognition developer, ArcGIS, ENVI) | Xia et al. (2021) |
S. No . | Hydrological indicators . | Methods/technologies . | References . |
---|---|---|---|
1. | Water salinity, water depth, water temperature, salt marsh diversity, soil water content, soil redox, soil conductivity, soil organic matter, sediment texture, soil bulk density, soil conductivity, soil pH, soil salinity, pore water salinity, soil organic matter | – | Billah et al. (2022) |
2. | Wetland depth, consistency in water appearance, stability of hydrology, eco deficit, and failure | Remote sensing (NDWI, MNDWI – range of variability approach and flow duration curve methods, FDC curve, range of variability approach (RVA) approach) | Pal & Sarda (2020) |
3. | Land–water threshold dynamics, hydro-potential zones, hydro-geomorphic dynamics, hydro-period, and water presence frequency | The satellite imagery based remote sensing indices (NDWI and NDVI have been calculated using the Landsat imageries, MNND) | Mukherjee & Pal (2021) |
4. | Land–water threshold dynamics, hydro-potential zones, hydro-geomorphic dynamics, hydro-period, and water presence frequency | The satellite imagery based remote sensing indices (NDWI and NDVI have been calculated using the Landsat imageries, MNND) | Mukherje & Pal (2021) |
5. | Hydrological variability | Time series remote sensing data (image-based hydrological attributes integration, histogram comparison approach (HCA), RVA) | Pal & Sarda (2021) |
6. | Net wetness and water depth wetness over a period Shoreline dynamics | NDWI Theil–Sen estimator slope hydrogeomorphic (HGM) | Singh & Sinha (2021) |
7. | Index of hydrological connectivity (IHC), root parameters, and soil properties | Field dye-tracing experiments, back propagation (BP) neural networks, global sensitivity and uncertainty analyses, and statistical analysis | Zhang et al. (2021) |
8. | Hydro-period, water presence frequency, water depth calculation | Time series Satellite Images – Landsat | Khatun et al. (2021) |
10. | Hydrological connectivity composite index (average annual precipitation, artificial influence rate, water area rate) | LANDSAT – (eCognition developer, ArcGIS, ENVI) | Xia et al. (2021) |
Vegetation indicators and the successful methods/technologies
S. No. . | Vegetation indicators . | Methods/technologies . | References . |
---|---|---|---|
1. | Wetland ecological index (WEI), improved hyperspectral image-based vegetation index | LANDSAT, Mann–Kendall test, and Theil–Sen median trend analysis | Zhang et al. (2023a, 2023b) |
2. | Macrophyte community | SNAP – ESA Sentinel Application Platform v8, ML algorithms | Piaser & Villa (2023) |
3. | Vegetation species | GEOBIA, UAV, spatial scale, aerial images, resampled images, machine learning classifier | Chen et al. (2023) |
4. | Vegetation phenology (bud burst, canopy growth, flowering, and senescence) | ENVI 5.6, NDVI time series | Gao et al. (2023) |
5. | Relationships between vegetation cover and water quality indexes | Self-organizing map (SOM) and geographically and temporally weighted regression (GTWR) | Feng et al. (2023) |
6. | ENDVI, EVSI, NDVI, and WAVI | PlanetScope and RapidEye images – LANDSAT 5 TM | Zhang et al. (2022) |
7. | Vegetation cover, stem density, stem height | – | Billah et al. (2022) |
8 | 3D vegetation structure (vegetation height, biomass) | Airborne laser scanning (ALS) | Koma et al. (2021) |
9. | Mean biomass, sedge, grass, perennial plan, annual plant, total number of species, species richness index, Pielou evenness index, and Simpson diversity index | Pearson correlation, remote sensing | Luo et al. (2022) |
S. No. . | Vegetation indicators . | Methods/technologies . | References . |
---|---|---|---|
1. | Wetland ecological index (WEI), improved hyperspectral image-based vegetation index | LANDSAT, Mann–Kendall test, and Theil–Sen median trend analysis | Zhang et al. (2023a, 2023b) |
2. | Macrophyte community | SNAP – ESA Sentinel Application Platform v8, ML algorithms | Piaser & Villa (2023) |
3. | Vegetation species | GEOBIA, UAV, spatial scale, aerial images, resampled images, machine learning classifier | Chen et al. (2023) |
4. | Vegetation phenology (bud burst, canopy growth, flowering, and senescence) | ENVI 5.6, NDVI time series | Gao et al. (2023) |
5. | Relationships between vegetation cover and water quality indexes | Self-organizing map (SOM) and geographically and temporally weighted regression (GTWR) | Feng et al. (2023) |
6. | ENDVI, EVSI, NDVI, and WAVI | PlanetScope and RapidEye images – LANDSAT 5 TM | Zhang et al. (2022) |
7. | Vegetation cover, stem density, stem height | – | Billah et al. (2022) |
8 | 3D vegetation structure (vegetation height, biomass) | Airborne laser scanning (ALS) | Koma et al. (2021) |
9. | Mean biomass, sedge, grass, perennial plan, annual plant, total number of species, species richness index, Pielou evenness index, and Simpson diversity index | Pearson correlation, remote sensing | Luo et al. (2022) |
Remote sensing using machine learning methods is a highly used method to determine the hydrological indicators in the wetlands, reflecting the divergence in accuracy. The hydrological parameters listed in the above table have been studied using a variety of remote sensing approaches, including field dye-tracing studies, histogram comparison approach, and time series remote sensing data. To determine the basic hydrological parameters simple cluster analysis and ANOVA (Santoro et al. 2023) could be used. Time series analysis was carried out to study the hydrological parameters in three water bodies meant for fish culture in East Kolkata Wetlands (Roy et al. 2016). The increased load of these parameters adversely impacted the population of phytoplankton standing stock.
Vegetation indicators
By providing food for the wetland's animals and enhancing the water quality, the flora of the wetland performs a crucial function. Hence, the vegetation in the wetland is one of the biological indicators and could be used to monitor the hydrological changes, nitrogen content, silt, and turbidity and even the concentration of the metals and other contaminants (Table 3). Zonal variation of the flora can change due to the drainage and flooding (EPA, United States). How plants use water in different water settings is crucial to understanding the patterns of wetland vegetation and undertaking ecological regulation of wetlands (Zhang et al. 2023a, 2023b).
As a result of changes in the external environment, plants can modify their water sources to satisfy their growing needs (Yue et al. 2021). According to Yamanaka et al. (2020), wetland vegetation is made up of hygrophytes and hydrophytes, which are aquatic macrophytes that are free-floating and adaptable with sunken leaves. Compared to channelized watercourses, the drainage pumping station, remnant ponds, and flood control basins each had significantly higher levels of species richness and wetland plant coverage. While phenology features are so effective at resolving identical spectral conditions, phenology events are very helpful for classifying different types of vegetation, notably coastal wetland vegetation properties of the diverse species of plants (Gao et al. 2023). The value of high-resolution satellite photographs, such as Planet Scope and Rapid Eye, was that they supported distinct phases of scientific inquiry (Mejia Avila et al. 2023). Based on its flexibility and quantitative adaptability, the Soil Quality Index may be compared more precisely in various vegetation species of wetland habitats (Zhang et al. 2022).
The above general overview of the vegetation indicators shows that this will help understand the evaluation of functional indicators. Water bodies should be purified by the natural flora in the ecosystem, which controls the discharge of pollutants (Feng et al. 2023). The flora of the wetland progressively evolved tactics of survival, such as altering its life cycle and morphology through long-term evolution, controlling the physiological mechanism (Yao et al. 2020). Due to their sedentary nature, wetland plants have a significant potential for use as indicators of the health of the ecosystem (Dybiec et al. 2020).
ANTHROPOGENIC THREATS FACED BY WETLANDS
The impact of anthropogenic climate shifts on wetland health
In just 50 years since 1970, 35% of the world's wetlands have vanished. Because they sustain a wide range of species populations and ecosystems and carry out ecological, hydrological, physiographic, and cultural functions, wetlands are essential to many forms of life (Ramsar Convention on Wetlands 2018). For the last two decades, the wetlands faced much destruction on their landscapes, hydrological connectivity, and quality of water due to both anthropogenic activities and natural causes (Nahlik & Fennessy 2016). Wetlands provide water storage, act as a buffer against inland and coastal storms, cool the surrounding areas, and store floodwaters, making them essential to the more immediate and localized aspects of climate resilience. One of the key driving mechanisms for landscape change is human disturbance. Due to growing human activity and global climate change, many wetlands have seen substantial degradation; their extent has decreased, they have deteriorated, and their value and purpose have lost significance (Davidson et al. 2019; Zhu et al. 2022a, 2022b). Although it is widely accepted that climate variability and human activity both contribute significantly to the process of wetland degradation, their respective contributions may change over time (Zhu et al. 2022a, 2022b). Wetlands play a crucial regulatory role in helping aquatic creatures adapt to the effects of climate change. Among the places most affected by climate change globally are aquatic ecosystems, and wetlands are no exception (Choudhury et al. 2021). Due to climate change, which causes such wetlands to dry out in certain months and some years, the wetlands are currently experiencing an intense drought (Melaki et al. 2021). Multiple contaminants released by human activity have always entered natural watersheds, triggering physiochemical and biological alterations to waterbodies (Zhu et al. 2022a, 2022b). Therefore, investigating the origins, distribution, and exposure risk of the water characteristics requires the application of water quality evaluation (Wu et al. 2021; Zhu et al. 2022a, 2022b).
Human disturbances on wetlands
One of the key driving mechanisms for landscape change is human disturbance. The regional ecological processes and functions are influenced by the regional landscape pattern, which also dictates the shape of the spatial distribution of its resources and environment (Cui et al. 2021). Liu et al. (2021) said that from the standpoint of structure process function coupling, essential ecological aspects of regional wetland restoration were quantified, including healthy and dynamic intertidal wetland systems and they derived a conceptual ecological model of regional wetland restoration. The wetlands begin to degrade severely when a combination of internal pressure sources, external key drivers, ecological effect, and ecological features is present. The degradation and loss of wetlands have been related to a number of variables, including overfishing and overexploitation, global climate change, infrastructure expansion, land conversion, eutrophication and pollution, infrastructure growth, infrastructure withdrawal, and population growth (Chen et al. 2019).
Numerous coastal wetlands have degraded because of increased urbanization and climate change, compromising the ecosystem services they provide. Few studies, particularly in quickly emerging regions, have examined how these historical degradation trends will persist in the future (Hu et al. 2020). Human activity, particularly aquaculture and urbanization, was found to be substantially connected with wetland deterioration. Illegal encroachments often happen near the wetlands. Contributing problems include inadequate drainage systems, stormwater drain encroachment, blockages from negligent construction debris and solid waste management, loss of natural flood-storage sites, and loss of pervious space in urbanizing landscapes (Ramachandra et al. 2012). Sediments are a naturally occurring substrate that aids in the cycling of nutrients, assists the growth of aquatic plants, and increases biological productivity (Dar et al. 2022); hence, the people do not think about the disturbance of wetland sediment. Furthermore, due to unplanned urbanization, industry, and encroachments that cause degradation, wetlands are among the most vulnerable habitats in the world (Murali 2021). The non-human entity's legal personality may be necessary for the effective enforcement or defense of its rights (Cadaru 2019).
Pollution caused by the discharge of garbage into aquatic habitats endangers all life forms both directly and indirectly (Bhat et al. 2022). The human disturbance score protocol technique, which takes into account pollution levels (chemical, physical, and biological contamination), hydrological alterations (water abstraction, drainage, and dams), and changes in land use (urbanization, agriculture, and industry) is used to determine the extent of human disturbance to the wetlands. These factors collectively assess the extent of anthropogenic pressure on ecosystems was utilized (Krishnaraj & Mathesh 2022). Sewage water disposal is the main problem in the urban wetlands as people are thinking it as a wasteland so that thought should be changed by giving awareness about the benefits and services of urban wetlands. If immediate action is not taken, the hydrological and edaphic characteristics will be vanished completely. Hence, human disturbances in wetlands have to be avoided.
Wetland ecosystem benefits
Because they offer so many advantages on an ecological, economic, and social level, wetland ecosystems are extremely valued. Wetlands provide habitat to a diverse range of plant and animal species, many of which are uncommon or endangered, and thus sustain high biodiversity ecologically (Mitsch & Gosselink 2015). They act as natural water filters, improving water quality by trapping pollutants, sediments, and nutrients (Zedler & Kercher 2005). Wetlands play a crucial role in flood regulation, absorbing excess water during heavy rains and releasing it slowly, which reduces the impact of floods and erosion downstream (Costanza et al. 1997). Economically, wetlands contribute to livelihoods through activities such as fishing, agriculture, and tourism (Barbier et al. 1997). Socially, they offer recreational opportunities and cultural value to local communities (MEA 2005). Furthermore, according to Brigham et al. (2006), wetlands function as carbon sinks, storing carbon dioxide and reducing the effects of climate change. Their ability to store and release water also supports groundwater recharge, ensuring a sustainable supply of fresh water (Carter 1996). Overall, wetlands are essential for maintaining environmental health and resilience, supporting human well-being, and providing critical ecosystem services.
Contaminations of water in wetlands
Wetlands are highly susceptible to various forms of water contamination due to their role as natural filters for surface and groundwater. One of the primary sources of contamination is agricultural runoff, which often carries pesticides, herbicides, and fertilizers into wetland areas. These chemicals can be toxic to aquatic life, reducing biodiversity and disrupting ecosystem functions (Ritter et al. 2002). Increased levels of nitrogen and phosphorus in particular can lead to eutrophication, which can result in toxic algal blooms that lower oxygen levels and produce dead zones (Smith et al. 1999; Balakumar & Das 2015). In addition, industrial discharges, including heavy metals and other pollutants, can accumulate in wetland sediments, posing long-term environmental and health risks (Forstner & Wittmann 2012).
Urbanization significantly contributes to wetland water contamination through stormwater runoff, which collects pollutants from roads, rooftops, and other impermeable surfaces. Common contaminants include oil, grease, heavy metals, and debris, which can severely impact water quality and aquatic habitats (Paul & Meyer 2001). Untreated sewage and landfill leachate are two examples of improper waste disposal that can introduce a variety of contaminants into wetland habitats, including infections, medications, and personal care items (Kinney et al. 2006). These contaminants threaten wildlife and pose significant risks to human health, particularly when wetlands are used for recreational purposes or as a source of drinking water. The research work carried on various pollutants is shown in Table 4.
Pollutants found in wetland waters along with their sources
Pollutant . | Source . | Reference . |
---|---|---|
Nitrogen (N) | Agricultural runoff, wastewater, atmospheric deposition | Smith (2003) |
Phosphorus (P) | Fertilizers, detergents, sewage | Sharpley & Wang (2014) |
Heavy metals | Industrial discharge, mining, urban runoff | Alloway (2013) |
Pesticides | Agricultural runoff, urban runoff | Stehle & Schulz (2015) |
Sediments | Soil erosion, construction activities, deforestation | Wood & Armitage (1997) |
Pathogens | Sewage, livestock waste, wildlife excrement | |
Gerba & Smith (2005) | ||
Organic matter | Wastewater, agricultural runoff, decaying vegetation | Correll (1998) |
Pharmaceuticals | Human and veterinary drug waste, wastewater treatment plants | Kümmerer (2009) |
Pollutant . | Source . | Reference . |
---|---|---|
Nitrogen (N) | Agricultural runoff, wastewater, atmospheric deposition | Smith (2003) |
Phosphorus (P) | Fertilizers, detergents, sewage | Sharpley & Wang (2014) |
Heavy metals | Industrial discharge, mining, urban runoff | Alloway (2013) |
Pesticides | Agricultural runoff, urban runoff | Stehle & Schulz (2015) |
Sediments | Soil erosion, construction activities, deforestation | Wood & Armitage (1997) |
Pathogens | Sewage, livestock waste, wildlife excrement | |
Gerba & Smith (2005) | ||
Organic matter | Wastewater, agricultural runoff, decaying vegetation | Correll (1998) |
Pharmaceuticals | Human and veterinary drug waste, wastewater treatment plants | Kümmerer (2009) |
Various restoration strategies and technologies
S. No. . | Restoration strategies . | Description . | Reference . |
---|---|---|---|
1. | Artificial water replenishment | This method is modeled using a code model for environmental fluid dynamics with the help of water quality indicators | Liu et al. (2022) |
2. |
|
| Karim et al. (2022) |
3. | Reshaping channel morphology | To reclaim the original form of a river/flood plain, which including straightening a channel shape into a plea/meander | Cai et al. (2021) |
4. | Marsh terracing – remote sensing | Soil berms constructed within small coastal ponds to increase marsh area and reduce wave energy by using Remote sensing | Osorio et al. (2020) |
5. | Phytoremediation, microbial restoration, water replenishment, and water–soil engineering restoration | An assessment was made of wetland restoration technology development in China and other countries | Zhou et al. (2020) |
6. | Seed-based approaches | To recreate the underlying vegetation structure and composition that underpins these critical functions and services | Kettenring & Tarsa (2020) |
7. | Rainwater catchment system | The soil would be wet for a long period if rainwater collecting systems were designed for the marsh and its environs | Qaderi & Rahnama (2020) |
8. | Blue carbon accounting model (BlueCAM) | Tidal barrier removal and alteration can result in large greenhouse gas mitigation benefits for coastal wetlands (mangroves, seagrass, saltmarsh, and supratidal forests) | Lovelock et al. (2022) |
9. | Infiltration experiment | To some degrees, optimum saltwater concentrations promote soil water infiltration and circulation | Wang et al. (2023) |
10. | Control of Invasive plants | The plants which cause various threat to wetlands has to be identified and removed | Dehez (2023), Marangi et al. (2023) and Marchante et al. (2023) |
11. | Recovery of tidal exchange | Tidal exchange has been recovered and repaired by a variety of methods, including culvert building, canal and/or channel excavations | Wasser (2019) and Billah et al. (2022) |
S. No. . | Restoration strategies . | Description . | Reference . |
---|---|---|---|
1. | Artificial water replenishment | This method is modeled using a code model for environmental fluid dynamics with the help of water quality indicators | Liu et al. (2022) |
2. |
|
| Karim et al. (2022) |
3. | Reshaping channel morphology | To reclaim the original form of a river/flood plain, which including straightening a channel shape into a plea/meander | Cai et al. (2021) |
4. | Marsh terracing – remote sensing | Soil berms constructed within small coastal ponds to increase marsh area and reduce wave energy by using Remote sensing | Osorio et al. (2020) |
5. | Phytoremediation, microbial restoration, water replenishment, and water–soil engineering restoration | An assessment was made of wetland restoration technology development in China and other countries | Zhou et al. (2020) |
6. | Seed-based approaches | To recreate the underlying vegetation structure and composition that underpins these critical functions and services | Kettenring & Tarsa (2020) |
7. | Rainwater catchment system | The soil would be wet for a long period if rainwater collecting systems were designed for the marsh and its environs | Qaderi & Rahnama (2020) |
8. | Blue carbon accounting model (BlueCAM) | Tidal barrier removal and alteration can result in large greenhouse gas mitigation benefits for coastal wetlands (mangroves, seagrass, saltmarsh, and supratidal forests) | Lovelock et al. (2022) |
9. | Infiltration experiment | To some degrees, optimum saltwater concentrations promote soil water infiltration and circulation | Wang et al. (2023) |
10. | Control of Invasive plants | The plants which cause various threat to wetlands has to be identified and removed | Dehez (2023), Marangi et al. (2023) and Marchante et al. (2023) |
11. | Recovery of tidal exchange | Tidal exchange has been recovered and repaired by a variety of methods, including culvert building, canal and/or channel excavations | Wasser (2019) and Billah et al. (2022) |
By changing hydrological cycles and raising the frequency of extreme weather events like heavy rains and floods, which can wash additional pollutants into wetlands, climate change exacerbates the contamination of wetlands (Erwin 2009). Rising temperatures can enhance the release and mobility of contaminants, such as mercury and other persistent organic pollutants, from sediments (Obrist et al. 2018). Emerging contaminants, including microplastics and endocrine-disrupting chemicals, are increasingly being detected in wetland environments, presenting new challenges for water quality management (Rochman et al. 2013). Wetland ecosystems are susceptible to complex and unpredictable effects from these contaminants, which emphasizes the need for careful monitoring and adaptive management techniques to save these essential habitats.
Natural disturbances on wetlands
Climate change
Wetlands are vulnerable to both direct and indirect effects of climate change, including changes in temperature, the intensity and frequency of rainfall, and the frequency of extreme weather phenomena like drought, flooding, and storms. Environment change is predicted to hasten the loss and degradation of many wetlands because of the intricate relationships that exist between wetlands and the environment. As a result of their extensive inundation and high temperatures, tropical and subtropical wetlands produce more than 80% of the natural sources and at least 50% of the total wetland methane emissions (Meng et al. 2016). Climate change significantly impacts wetland dynamics by altering hydrological cycles, increasing temperature, and causing sea-level rise, which can lead to changes in wetland areas, shifts in species composition, and reduced water quality (Erwin 2009). The equilibrium of these ecosystems is upset when extreme weather events occur more frequently and intensely (IPCC 2014). In addition, changes in precipitation patterns can affect the seasonal availability of water, further stressing wetland environments (Erwin 2009). Sea-level rise particularly affects coastal wetlands, causing habitat loss and saltwater intrusion, which further stress plant and animal communities (Nicholls 2004). These factors collectively threaten the ecological integrity and functioning of wetlands, making their conservation increasingly challenging (Junk et al. 2013). If wetlands are destroyed, burned, or drained, millions of years' worth of carbon dioxide could be released into the sky, turning them into a carbon source. Wetlands are essential to comprehending how climate change impacts the ecosystem because they have the inherent capacity to regulate the amount of greenhouse gasses in the atmosphere. Climate change affects the wetland's aerobic and anaerobic conditions, which in turn affects the pace at which methane and carbon dioxide are generated (Salimi et al. 2021). The UN General Assembly and the Ramsar Convention have recognized that coastal ‘blue carbon’ habitats have the potential to be instrumental in reducing climate change through carbon sequestration (Australian Govt, Dept of Environmental & Energy) and also stated that around 10% of annual global emissions of carbon dioxide from fossil fuels come from peatlands that have been burned and drained. Mangrove wetlands are responsible for the sea-level rising and atmospheric CO2 concentration (Wang & Gu 2021). Sea-level rise, coral bleaching, and altering hydrology all influence wetlands, putting Arctic and montane wetlands in particular danger (Convention on Wetlands 2021). It will be crucial to ascertain the precise anticipated future changes in each region's climate as well as to carry out appropriate monitoring to find out how well actual conditions match the climate change model for that location (Erwin 2009). Many investigations have been done based on the greenhouse gas emissions and nutrient releases caused by a natural wetland, a peatland, and a man-made wetland in reaction to climate change (Salimi et al. 2021). The impact of urban development (Li et al. 2022a, 2022b) around the wetland ecosystem will cause climate change and hydrological effects.
Impact of invasive plants
The invasion of invasive species into wetland ecosystems is influenced by multiple mechanisms, prominently driven by eutrophication. By increasing nutrient availability and changing the competitive dynamics of native flora and fauna, eutrophication, which is mainly brought on by excessive nutrient inputs from agricultural runoff, sewage discharge, and atmospheric deposition of nitrogen and phosphorus compounds, accelerates the growth of invasive species (Smith et al. 1999; Hilt et al. 2006). Invasive plants like P. australis and Typha spp. proliferate due to this nutrient enrichment, outcompeting native species that have adapted to lower nutrient levels (Chambers et al. 1999; Meyerson et al. 2000). Furthermore, eutrophication-induced changes in water quality and habitat structure can create favorable conditions for invasive species establishment and spread, disrupting the ecological balance of wetland ecosystems (Davis et al. 2000; Gordon et al. 2005).
Clonal fragmentation and floatability (Roiloa et al. 2020) have been discussed as successful dispersal strategies for invasive species. There are some chances that the removal of invasive plants can increase species and phylogenetic diversity in the wetlands (Lishawa et al. 2019). Harvesting of the invasive plants will reduce the loads of heavy nutrients and produce new more biomass (Carson et al. 2018). Plant invasion increased yearly N2O emission rates in grasslands but did not affect forests. According to some contextual methods (Bezabih Beyene et al. 2022), invaded coastal wetlands had the largest increases in annual CH4 emission rates, while invaded grasslands had the highest increases in annual CH4 uptake rates. Native woody species of wetlands would particularly experience habitat loss, while non-native, non-wetland species would gain from climate change and see an expansion in their ranges (Zhong et al. 2022). Effective management strategies must therefore prioritize reducing nutrient inputs and restoring natural hydrological regimes to mitigate the impacts of eutrophication and curb the spread of invasive species in wetlands.
RESTORATION STRATEGIES FOR WETLANDS
Since each type of wetland has a unique ecology marshland, mangroves, peat lands, and bogs, for example, restoration tactics will also differ depending on the wetland's characteristics, landscape, hydrological connectivity, and types of anthropogenic activity surrounding it. The United States conducted the first research on rebuilding and restoring damaged wetlands (Zhou et al. 2020). Between 1970 and 2015, over 35% of the world's natural wetlands disappeared (An et al. 2019). Assistance and administration are the two primary responsibilities. The process of restoring wetlands involves putting them back in their natural state after being disturbed or altered by human activity, restoring the hydrological conditions and ecological system while giving priority to the balance of various organisms in wetlands, temperature, and plants using natural and ecological laws (Cai et al. 2021). The following strategies are used for ecological restoration of wetlands:
Plant restoration
Animal restoration
Microorganism restoration (Cai et al. 2021).
In India, ecological plant restoration strategies for wetlands typically involve a combination of approaches aimed at enhancing biodiversity, improving ecosystem functions, and restoring hydrological regimes. Key strategies include the establishment of native plant species through seed banking and propagation programs, such as those undertaken by organizations like the Salim Ali Centre for Ornithology and Natural History (SACON) and the National Biodiversity Authority (NBA) (SACON 2020; NBA n.d.). These efforts focus on selecting species that are adapted to local environmental conditions and are crucial for maintaining habitat structure and supporting native fauna. In addition, community-based initiatives play a significant role, involving local stakeholders in wetland restoration activities to ensure sustainable management practices and promote socioeconomic benefits (Gupta et al. 2019). Restoration projects also integrate measures to control invasive species and mitigate anthropogenic impacts, such as pollution and habitat degradation, which threaten wetland ecosystems across the country (Menon et al. 2021). By implementing these strategies, India aims to conserve and restore its wetland biodiversity while safeguarding the ecological services these vital ecosystems provide.
The strategies for animal restoration primarily focus on habitat restoration and conservation measures aimed at supporting native fauna populations. Key approaches include creating protected areas and wildlife sanctuaries, such as the Chilika Lake Wildlife Sanctuary in Odisha and the Bharatpur Bird Sanctuary in Rajasthan, which provide essential habitats and breeding grounds for diverse bird species (Sundar 2009; Sivaperuman et al. 2017). In addition, efforts are made to control invasive species that threaten local wildlife, as seen in initiatives to manage invasive fish species in wetland ecosystems such as the Vembanad-Kol Wetland in Kerala (Easa & Shaji 2004). Community participation is integral to these restoration efforts, with local stakeholders engaged in monitoring and conservation activities to ensure sustainable management practices and the preservation of wetland-dependent species (Ghosh et al. 2020). Through these integrated approaches, India aims to safeguard its wetland biodiversity and enhance ecological resilience in the face of ongoing environmental challenges.
Microbial restoration strategies involve measures to restore natural microbial communities that play vital roles in nutrient cycling, water purification, and overall wetland resilience. Key approaches include restoring hydrological regimes to promote anaerobic conditions favorable for beneficial microbial activity, such as denitrification and organic matter decomposition (Singh et al. 2018). Various restoration strategies and technologies are shown in Table 5. In addition, efforts are made to reduce nutrient pollution and control invasive species that can disrupt microbial communities, as seen in initiatives targeting nutrient runoff and invasive aquatic plants in wetlands like the Keoladeo National Park in Rajasthan (Bhatnagar et al. 2007; Kundu et al. 2014). Integrated management plans also emphasize monitoring microbial biodiversity and ecosystem function to assess restoration success and inform adaptive management strategies (Mandal et al. 2016). Through these efforts, India aims to restore and sustain the ecological functions of its wetland microbial communities while mitigating threats to their integrity.
Every restoration project is different, and there is no ‘prescription’ for restoring wetlands (Zhu et al. 2019). Many approaches to conservation have been applied, but there are very less methods to remove and control invasive plants. Even though we are given many possibilities to restore the wetlands, the success of the restoration is based on how we monitor and develop the wetlands.
KEY CHALLENGES OF WETLAND RESTORATION
Early theories of ecosystem deterioration and restoration understate the complexity of wetland restoration (Zedler 2000). Restoration of wetlands and bays is complicated by several issues that are more social, cultural, economic, and stakeholder than ecological (Root-Bernstein & Frascaroli 2016). The natural ecological environment is under a lot of pressure because of the overconsumption of natural resources and severe environmental pollution brought on by urban sprawl and modernization. While using various wetland restoration strategies, there are some challenges we are going to face. The evaluation techniques and index systems utilized in ecology security evaluation are variable as a result of various ecosystem kinds, research objectives, and disciplinary backgrounds (Fan & Fang 2020). Degradation and restoration, for instance, have been shown as straight arrows traveling along parallel courses in opposite directions (Dobson et al. 1997; Zedler 2000). In some wetlands, the weak legal system and unclear system are the main obstacles in the restoration process. The lack of awareness in people quietly leads to some failures after the successful restoration. The difficulty of establishing long-term protection of compensation zones presents another legal challenge (Blicharska et al. 2022). In quite a while, there have been few science-based recommendations for how to make decisions on what to avoid, as well as standards for locations where avoidance is most crucial (Bigard et al. 2020). Clarke et al. (2021) recorded the viewpoints of environmental organizations, individuals who use and travel to the area for environmentally friendly activities, as well as locals engaged in fishing operations. Hughes et al. (2016) encountered an assortment of practical difficulties, such as the requirement for high levels of varying expertise, high prices, incommensurate monitoring outputs, and the requirement for careful control of monitoring outcomes. To target wetland restoration areas more effectively, ecological health, water quality improvement, and hydrological health should be considered (Clare & Creed 2022). Addo-Bankas et al. (2022) observed that the chemical processes offer a threat to the environment and may result in secondary pollutants like sludge, and in terms of mechanical techniques, the high installation costs as well as the long-term environmental effects that have been seen make them undesirable.
OVERALL ECONOMIC BENEFITS OF WETLANDS
The contribution of wetlands to the Earth is not enough to detail, but the local and national economies are getting benefitted throughout the year. Wetlands provide significant economic advantages to a variety of industries, including agriculture, fisheries, water supply, tourism, and the control of nitrogen cycles and water tables. It also contributed in the retention of floodplains, production of timber, energy resources (plant matter and peat), wildlife resources, and chances for leisure and tourism (Lambert 2003). They contain some of the most productive ecosystems on the planet and provide ecological services (Gardner & Finlayson 2018). The water quality, flood control, fisheries, and some recreational activities (EPA, United States) are the major values from wetlands. Wetlands provide several nonmonetary benefits in addition to their numerous economic ones. To find out more about how much drainage practices benefit farmers financially, researchers are examining the productivity of agriculture in drained wetland basins (Clare et al. 2021). The constructed wetlands are more profitable (Canning et al. 2022) for the fresh water biodiversity in the field of agricultural productivity. Wetlands have a critical part in the idea of climate change because they both reduce greenhouse gas emissions and preserve long-term carbon storage (Malerba et al. 2022). Wetlands provide recreational opportunities as well as touristic incentives (Gardner & Finlayson 2018). Socioeconomic assessment techniques are quite useful for assessing elements such as the feasibility and economic effectiveness of several adaption alternatives (Riera-Spiegelhalder et al. 2023). Using the soil and water assessment tool (SWAT) model (Scott-Shaw et al. 2022), the hydrological advantage of wetland rehabilitation was ascertained.
The Environment, Climate Change & Forests (FR.9) Department is aiming to restore 100 targeted wetland areas and calculating the total economic value of wetland ecosystems helping local communities throughout the state (Dept. of Environment, Climate Change & Forests 2022). Wetland pricing is a method of estimating habitat benefits and services and enables financial specialists to perform a cost–benefit analysis that may encourage environmental investment (Lambert 2003). Parameterization and modeling used stable isotope data to derive the economic value (Taylor et al. 2018) so that we can express the model outputs and commercial values of a wetland. A mixed-method approach, such as semistructured questionnaires, remote sensing and GIS, and focused group discussions, might be used occasionally (Huq et al. 2020). To choose the best course of action for financial results, Dominici et al. (2022) integrated a number of multimethodological techniques, including the SWOT (strengths, weaknesses, opportunities, and threats) analysis, holistic diagnosis (HD), and systemic design (SD) (Battistoni et al. 2020). If decision-makers in the area are aware of the significance of wetlands for carbon sequestration, they may be able to adopt policies to manage wetlands in a way that maximizes their value and stops more wetland losses (Gallant et al. 2020). The market price method (Aryal et al. 2021) was used to calculate the market price and average home consumption. The great degree of local diversity, such as the closeness to metropolitan areas, the amount of waterfowl, and the demographics of the local people, presents a hurdle for estimating the recreational value of wetlands (Pattison-Williams et al. 2018). Only two of the ecosystem services offered by wetlands are direct benefits to the community, such as increased fish stock richness because of reduced nitrogen concentrations in the natural wetland and the availability of clean water (Ranjan 2021). It is imperative for the stakeholders to preserve the socioeconomic significance of the wetlands, especially without compromising the surrounding ecosystem and aquatic habitat.
EXPLORING THE SOCIAL AND CULTURAL SIGNIFICANCE OF WETLAND ECOSYSTEMS
Wetland ecosystems serve as integral spaces for various social and cultural activities worldwide, including in India, where they play significant roles in local traditions and livelihoods. These ecosystems provide essential resources such as fishing grounds, agricultural lands, and water sources crucial for communities' sustenance and economic activities (Biswas et al. 2017). In cultural contexts, wetlands often hold spiritual significance, serving as sites for rituals and ceremonies among indigenous and local communities (Nayak & Tripathy 2020). In addition, wetlands contribute to recreational activities like birdwatching, boating, and ecotourism, generating income and promoting environmental awareness (Gopal 2013). The East Kolkata Wetlands exemplify such dual-use scenarios, where traditional wastewater treatment practices coexist with biodiversity conservation and cultural practices (Ghosh et al. 2020). Recognizing these social and cultural dimensions is crucial for developing sustainable management strategies that balance conservation with human needs and traditions, ensuring the continued benefits of wetlands for generations to come.
CONCLUSION
The review on wetland restoration strategies and economic benefits underscores the efficacy of restoration efforts in enhancing ecosystem health and resilience while emphasizing the substantial economic returns from restored wetlands, demonstrating their value for sustainable development. This review conducted on studies and their evidence showcases the intensity of previous literature on the wetlands.
The global wetland policies display the combined overall functions of wetland policies around the world, technologies and methods used in wetland conservation, and the economic benefits derived from them. From the earlier studies, it is understood that despite robust policy frameworks, challenges persist in implementing and enforcing wetland conservation measures at a global level. Variations in national priorities, capacities, and financial resources hinder uniform adherence to conservation goals.
India has established a comprehensive legislative framework for wetland conservation. These frameworks provide a structured approach to identify, conserve, and manage wetlands, supported by institutional mechanisms such as the Central Wetlands Regulatory Authority and State Wetlands Authorities. Despite the existence of strong policy frameworks, India faces issues such as inadequate funding, conflicting development priorities, and varying enforcement capacities across states hinder the full realization of conservation goals. Addressing these challenges requires enhanced coordination among stakeholders, capacity building at the local level, and greater public participation to ensure sustainable management and protection of India's diverse wetland ecosystems.
Monitoring hydrological and vegetation indicators helps identify changes in wetland health over time and informs management strategies aimed at preserving or restoring these vital habitats.
Hence, integrated management with stakeholder engagement helps address multiple anthropogenic threats simultaneously. Planning land use, pollution management, community involvement, and legislative interventions are all important components of effective conservation methods that aim to lessen human impacts on wetlands and guarantee their long-term survival.
Based on the above studies, further research can be focused on selection of most degraded wetlands, identifying anthropogenic activities such as pollution around the wetlands, finding the relationship between hydrological indicators and vegetation indicators, recognizing the invasive plants and suitable plans to remove them, integrated management and restoration plan for wetlands to achieve sustainability, and constant monitoring of the wetlands to evaluate their health. Wetland restoration is not only the role of the government but also lies in the understanding of its importance and sustainable measures to be taken by the local network and environmentalists. Proper monitoring systems should be used to conserve the wetland ecosystems and can act as a good tool for the sustainability of the natural ecosystems.
DATA AVAILABILITY STATEMENT
All relevant data are included in the paper or its Supplementary Information.
CONFLICT OF INTEREST
The authors declare there is no conflict.