Introduction
A wetland is a special kind of semi-aquatic habitat in which the groundcovers are continually or periodically saturated with water throughout many years or decades. Particularly in the soils, flooding causes oxygen-poor processes to occur.1 Because the roots of their vegetation have adapted to oxygen-poor waterlogged soils, wetlands are distinct from other terrestrial or aquatic ecosystems and constitute a transitional zone between waterbodies and dry lands. Among the most biologically diverse ecosystems, they support a broad array of aquatic and semi-aquatic plants and animals and frequently have better water quality because plants filter out excess nutrients like phosphorus and nitrates.
Ramsar site: What Is It?
According to the definition given by ramsar.org, a Ramsar site is a wetland site that has been designated as being of international importance under the auspices of The Ramsar Convention. Under UNESCO's auspices, the Ramsar Convention,2 commonly known as "The Convention on Wetlands," is an international environmental agreement that was signed on February 2, 1971, in Ramsar, Iran. Once enough countries accepted it, it went into effect on December 21, 1975. Regarding the preservation of wetlands and the prudent, sustainable use of their resources, it calls for both domestic and international action. Ramsar designates wetlands of global significance, particularly those that serve as habitat for waterbirds. According to the data, as of October 2024, 635,845,060 acres were being protected with the involvement of 172 countries under 2523 Ramsar sites globally. Their primary goal is to preserve and responsibly utilize wetlands that have been identified as Ramsar areas. Each continent has a different distribution of the these 2523 wetlands of international importance. 2 Africa has the largest area of sites, whereas Europe possesses the most sites. Numerous issues, such as pollution, the use of biological resources, the alteration of natural systems, and agriculture and aquaculture, have an impact on more than half of the sites.
"Areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tides does not exceed six meters" comprise a wetland, according to the Ramsar Convention. Additionally, "wetlands may include riparian and coastal zones adjacent to the wetlands, and islands or bodies of marine water deeper than six meters at low tide lying within the wetlands," according to Article 2.1 of the Convention, which protects cohesive sites.
Inland wetlands, marine or coastal wetlands, and man-made wetlands are the three types of wetlands recognized by the Ramsar Convention.3 The sites that contain both natural and artificial inland wetlands are included in the category of inland wetlands. However, the marine or coastal wetlands comprise both natural and man-made wetland habitats, as well as locations that are both natural and coastal. The aforementioned three wetland types are further divided into forty-three subtypes by the Ramsar Convention.4 There are inland wetlands, such as permanent and seasonal rivers, inland deltas and floodplains, permanent and seasonal lakes and ponds, marshes, freshwater swamps, and peatlands; human-made wetlands, such as reservoirs, barrages, and dams; aquaculture ponds; excavations and burrow pits; wastewater treatment ponds; irrigation canals, ditches, irrigation ponds, and rice fields; and marine and coastal wetlands, such as open coasts, coral reefs, estuaries, tidal flats, mangroves, and coastal lagoons. These wetland forms frequently blend into one another and the broader landscapes due to their hydrological and ecological connections (Figure 1). Therefore, wetlands ought to be regarded as a component of the coastal zone or river basin. River wetlands, as well as marine and coastal wetlands, are the types of wetlands that have the greatest impacts on biodiversity and the ecosystem.
India has a wide distribution of Ramsar Sites. As of October 2024, India accounts for 85 Ramsar sites. According to the Ramsar Convention, these wetlands are considered to be of "international importance".2 The Indian government defines wetlands as places like paddy fields and river channels that are not utilized for commercial reasons, as stated in The Wetlands (Conservation and Management) Rules of 2017. The World-Wide Fund for Nature-India lists wetlands as one of India's most vulnerable habitats. The nation's wetlands have been harmed by invasive species, excessive development, road construction, salinization, excessive flooding, water pollution, and vegetation loss.5 The total geographical area of the Ramsar Sites is approximately 13,32,746.24 hectares. Tamil Nadu has more Ramsar Sites than any other Indian state (18).6 A complete state wise distributed list of Ramsar Sites in India is compiled as (Table 1) and their distribution across the country is depicted as (Figure 2).
Discussion
Ramsar Sites are essential to preserving the natural equilibrium. Wetlands are essential to the hydrological cycle and have a major impact on controlling water flow and quality, even though they only make up 2.6% of the planet's surface area. 7 Wetlands are also a vital source of nutrients and energy for many aquatic and terrestrial ecosystems, producing more than 20% of the earth's organic carbon. 8, 9 They are the ideal habitat for a variety of species since they have access to enough food and water. 10, 11 Numerous essential ecological services, including water purification, flood control, biodiversity preservation, food production, and carbon sequestration, are offered by wetlands.12 The sustainable development goals are achieved in part by the execution of the Ramsar Strategic Plan.13 Since rice is a staple food for around three billion people and is farmed in wetland paddies, these sites aid in the fight against world hunger.14 By controlling sediment transport, they also aid in the stabilization of coastal zones, land creation, and drought reduction.15 16 Wetlands serve as carbon sinks, and coastal wetlands mitigate the effects of sea level rise by controlling erosion and serving as storm surge buffers. The water, carbon, and nitrogen cycles would be drastically changed in the absence of wetlands.14
Table 1
State wise distributed list of ramsar sites in India(As on October, 2024)
Figure 2
Map showing distribution of Ramsar Sites across India Source: https://wiienvis.nic.in/WriteReadData/UserFiles/image/images/Ramsar%20Wetland%20Sites%20Map/Ramsar%20Sites%20October%202024.png)
Monitoring of Ramsar sites is very important. Supporting a wide variety of flora and fauna as well as several ecological niches, wetlands are among the most important elements of an ecosystem. Because of these sites' biological importance, it is essential to investigate changes in the amount of their flooding and suggest appropriate conservation actions. Even minor changes in the hydrologic regime can have a significant impact on the features and function of the ecosystem since wetland saturation and inundation are the most significant abiotic processes governing wetland area and function.17 In order to comprehend the health and function of wetlands as well as the ecological services they offer, it is crucial to monitor the inundation dynamics of these areas. Inundation maps are crucial for assessing the condition of any wetland. They are frequently employed to analyze the current and historical conditions of wetlands, predict future developments, and comprehend the effects of natural occurrences, human resources, and climate change.18, 19, 20 Additionally, they are helpful for biodiversity research and wetland management plans.21 However, traditional in-situ methods of data collecting alone cannot provide comprehensive and timely wetland change detection and delineation.22 When there is a shortage of personnel or for large or inaccessible areas, satellite imagery can be utilized to create inundation maps.23
One important source of information for tracking wetland dynamics is remote sensing. However, imaging radar has proven helpful in identifying water level changes in swamp forests24 and mapping wetland inundation.25 Wetland classification26 and change detection27, 28, 29 are two of the many wetland studies that have made use of Landsat data.30, 31 Comprehensive assessments of remote sensing datasets and methods for describing wetlands have been provided by Rundquist et al.32 and others.
Wetland deterioration is a matter that is of significant consequences. Unfortunately, because of climate change and human activity, wetlands—one of the most vulnerable ecosystems—have seen severe losses and degradation on a global scale.33, 34 Given the intimate connection between wetlands and climate, any shifts in their behavior are a reflection of shifting weather patterns and vice versa.35, 36 A framework for the preservation and prudent use of wetlands is provided by the convention. 36 By conserving and responsibly exploiting wetlands through national and local initiatives as well as international collaboration, the treaty seeks to promote sustainable development on a global scale.14
Anthropogenic activities continue to be the main cause of water quality degradation despite several attempts to safeguard delicate marine and inland ecosystems.37 Due to a lack of sewage treatment capacity, about 38,000 million gallons of untreated sewage water are released into Indian rivers every day.38 It has been demonstrated that different aquatic environments are negatively impacted by the combination of anthropogenic activity and climate change.39 The traditional method of monitoring water quality relies on on-site measurements, which are accurate but typically time-consuming and labor-intensive, making it challenging to continuously monitor water bodies.40 Furthermore, because these estimations are restricted to point-to-point data, extrapolation frequently becomes generalized in the intricate ecological problems pertaining to water bodies.41 A breakthrough for quick and simple comprehension of surface water quality was made possible by the use of satellite data products based on earth observation. At the regional or even global level, remote sensing data products offer spatially explicit and temporally frequent observations regarding the size and quality of water bodies42, 43. Since the 1970s, when the Landsat series was launched, remote sensing techniques have been used to map the extent of inland waterbodies, including wetlands, and their water quality.44
Wetland change and wetland destruction are the two categories of wetland threat factors. Human settlements, the construction of transportation and service corridors, natural system modifications (such as vegetation removal/land conversion, dams, and water management/use), and the occupation of wetland areas by agriculture and aquaculture are the main factors affecting the land area.3 The loss or degradation of wetlands in tropical and subtropical regions has increased as a result of their conversion to agricultural use.45 The exploitation of water resources also contributes significantly to the degradation of inland wetlands. Around the world, many rivers are tightly regulated by dams to satisfy the increasing need for hydropower and irrigation. Here, "wetland loss" pertains to the literal diminution of wetland acreage, which can be attributed to human interference and change in the climate.3
The wetlands' ecosystem and land area are the primary items impacted. Lake wetlands and river wetlands are most affected by land area occupation, while marsh wetlands and river wetlands are most affected by water resource regulation. In addition, the wetlands that are most impacted by climate change are the lake wetlands and the marine/coastal wetlands. A third or so of the wetland locations have been artificially recreated. Nonetheless, it is discovered that the percentages of natural wetland sites that are unaffected or only impacted by one factor are typically higher than those of wetland sites that have both natural and artificial wetlands. Furthermore, compared to natural wetland sites, the proportions of wetland sites with both artificial and natural wetlands affected by three or four factors are typically higher.
Are Wetlands of any Economic Value ?
The wetlands are of great socioeconomic significance and are among the world's most productive and diversified ecosystems.46 Both local populations and those living outside the perimeter can benefit from the many products and services that wetlands offer.47 Millions of people worldwide depend on wetlands for a variety of commodities and services. In fact, the products and services promote biological variety, the life support system, and serve as a safety net and environmental insurance against the effects of ecosystem degradation and climate change. In the words of Ramachandra et al.48, human actions have an influence on the biological, chemical, and physical processes of wetlands, which degrade the functioning of ecosystems and contribute to an overall reduction and degeneration of ecosystem functions as well as the financial significance of wetlands. According to estimates, wetland-related ecosystem services and direct goods are worth 14 trillion USD a year on a worldwide scale. 49 They supply fuel, food, fodder, and water for industrial, agricultural, and residential uses. Additionally, owing of their roles in the chemical and hydrological cycles, it also acts as the landscape's kidney. Wetlands are in danger because of watershed degradation and water diversion that alters water regimes, despite their vital role in preserving the ecosystem's health and supporting local residents' livelihoods. Wetlands have been lost or degraded in many regions of the world, primarily as a result of urbanization, agricultural usage, excessive local population exploitation, and poorly planned development projects.
Many studies on the economic value of wetlands have been conducted worldwide, but very few have examined the wetlands' overall economic contribution. According to Ramachandran et al.48, the annual value of goods and services from wetlands was estimated to be the second highest, at 14785 USD/ha, based on the assessment of 17 ecosystem services in 16 biomes, with a focus on social welfare. According to a number of studies, the primary cause of inadequate management of these resources is the lack of a clear definition of the products and services provided by wetlands, as well as the true economic worth of those services and their significance to social welfare and the local and national economies.
What can be done to protect and revive the wetlands?
To conserve and restore wetlands, humans must adhere to natural law. There are number of steps that can be taken in order to protect these wetlands around the world. Firstly, designated wetland protection zones can be created in areas with protection or with less wetland features. They can also be preserved by creating coastal parks, forest parks, water conservancy scenic spots, water source protection zones, etc. Pollution restrictions can be established to rigorously regulate the overall quantity of pollutants released into the wetland in order to mitigate the impact on the wetland environment. Wetland management and river basin environmental management can be combined to accomplish this. Pollutant discharge from home sewage, industry, agriculture, and animal husbandry, among other sources, should be tightly restricted in the areas surrounding wetlands, rivers, lakes, and seas.
The boundaries of species diversity can be established for the influence on wetland biodiversity. It's critical to help rare creatures reproduce and to make sure their numbers don't decline. Limits of wetland ecological water can be established for the impact on wetland water supplies. Wetland management and river basin water resources management can be combined to accomplish this. Wetlands' ecological water amount can be safeguarded by meticulously regulating the quantity of water they receive from water bodies such as lakes and rivers. Climate prediction studies should be conducted in advance to assess the effects of climate change on wetlands. Given the long-term drought climate, it is important to ensure the ecological water amount of wetlands beforehand and to promptly implement the ecological water supply in water-deficient areas. Wetland drainage should be established as soon as possible to prevent the secondary biological effects of prolonged precipitation on wetland overflooding. More scientific laws, rules, and policies on wetland conservation should be swiftly created to clamp down and punish wetland degradation in order to guarantee the seamless execution of wetland management. Every nation and region should enact laws, rules, and policies that are in line with local growth because their national conditions differ greatly.
At last, but the most important step to be taken is to raise global citizens' knowledge of wetland conservation, expanding the breadth of wetland protection globally, and educating the public about wetland resource preservation and resource distress are all critical. Even though there are a specific number of wetlands on each continent that have ratified the Ramsar Convention, their combined area makes up less than nineteen percent of all wetlands worldwide. As a result, the Ramsar Convention urges additional wetlands worldwide to participate in its protection.
Conclusion
Ramsar sites are globally significant, but human activities and climate change continue to significantly impact them. Pollutants from waste, urban waste water, household sewage, industrial effluents, and agricultural effluents are the main causes. Wetland habitats are also impacted by human invasions and disruptions of leisure and tourism activities. Climate change and extreme weather are the primary natural factors. The most severely affected areas are around lakes, large interior rivers, and coastlines. Most wetlands are coastal and marine, with lake and marsh wetlands being most vulnerable. Economic growth and rising sea levels are the main causes of pollution and climate change's effects on marine and coastal wetlands.
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