Wetland Ecosystem:

A wetland is a type of land area that is characterized by either being covered by water or saturated with water. This water source can originate from various sources, such as groundwater that seeps up from an aquifer or spring, nearby rivers or lakes, or even seawater in coastal areas that experience strong tides.

According to the Ramsar Convention on Wetlands, wetlands are defined as areas that may include marshes, fens, peat lands, or bodies of water, both natural and man-made. The water in these areas can be static or flowing, fresh, brackish or salt, and may include areas of marine water with a depth that does not exceed six meters during low tide. Wetlands are characterized as distinct ecosystems that serve as transitional areas between land and water. These areas are subject to periodic flooding, either permanently for long periods of time, or seasonally for shorter durations.

Wetlands can be found in various climates and are present on every continent, except Antarctica. These ecosystems can range in size from small isolated prairie potholes to vast salt marshes. Some of the world’s largest wetlands include the West Siberian Lowland, Amazon River Basin, and Hudson Bay Lowland. The Llanos de Moxos, situated in Bolivia, is recognized as the world’s largest protected wetland, covering an area of more than 17 million acres.

Types of Wetlands:

1. Swamps are types of wetlands that are characterized by being permanently saturated with water and dominated by trees. There are two types of swamps: freshwater swamps and saltwater swamps. Freshwater swamps usually occur on flat land around lakes or streams where the water table is high, and the water runoff is slow. The wet soil of these swamps supports the growth of water-tolerant plants such as cattails, lotus, and cypress, which play an essential role in maintaining the swamp’s ecosystem. Freshwater swamps are particularly common in tropical areas located near the equator.

Saltwater swamps are wetlands that originate from bare flats of mud or sand that are thinly covered by seawater during high tides. These types of swamps are characterized by having brackish water, which is a mixture of saltwater and freshwater. The Sundarbans, situated in India and Bangladesh, is a well-known example of a saltwater swamp that features the largest mangrove forest in the world.

2. Marshes are wetlands that are typically found in regions located north and south of the tropics, where swamps give way to these grassy areas. These wetlands are characterized by forming a flat, grassy fringe that is typically situated near river mouths, bays, and coastlines. Marshes are often subjected to the movement of tides and are alternately flooded and exposed. Marshes can be divided into different subtypes.

3. Bogs are a type of wetland that are commonly found in colder regions, including Arctic areas in North America, Europe, and Asia. In Europe, bogs are often referred to as moors or fens, while in Canada, they are called muskegs. These wetlands typically develop in areas where the water table is high. The accumulation of partially decayed vegetation, which is the oldest material found at the bottom of the bog, forms a thick and spongy mat called peat. Unlike other types of wetlands, bogs are generally not agriculturally fertile due to the high amount of acidity in the soil and water. Additionally, bogs have limited species of plants and lack the biodiversity commonly found in other types of wetlands.

Wetlands provide various ecosystem services related to water and are significant in maintaining water security, resilience to storms, and adaptation to climate change. They help regulate water quantity, recharge groundwater, control erosion and sediment transport, and mitigate the impacts of floods and storms. Wetlands are highly productive ecosystems, with greater species diversity, nutrient recycling, and niche specialization compared to many other habitats. Additionally, wetlands are major habitats for most of the world’s waterbirds and key habitats for migratory species. Almost all waterbirds use wetlands as feeding and breeding grounds, and migratory waterbirds rely on wetlands throughout their range, which can span from pole to pole.Conservation efforts are crucial for migratory birds, whose feeding and breeding areas span continents. Wetlands provide essential ecosystem services such as water regulation, erosion control, and improved water security. They are productive habitats for plant and animal life, including agriculture, and support fisheries and aquaculture. Wetlands are also crucial for the majority of waterbirds and key migratory species.

Indian Wetlands:

• Globally, wetlands cover around 4% of the world’s geographical area.
• In India, wetlands cover 1,52,600 sq km, which is 4.63% of the country’s total geographical area, according to the National Wetland Inventory and Assessment compiled by the Indian Space Research Organisation (ISRO).
• Inland-natural wetlands account for 43.4% and coastal-natural wetlands account for 24.3% of the wetland area.
• Wetlands in Gujarat cover the largest area, with 34,700 sq km (17.56% of the total geographical area of the state), followed by Andhra Pradesh (14,500 sq km), Uttar Pradesh (12,400 sq km), and West Bengal (11,100 sq km).
• The wetland area includes rivers/streams (52,600 sq km), reservoirs/barrages (24,800 sq km), inter-tidal mudflats (24,100 sq km), tanks/ponds (13,100 sq km), and lake/ponds (7300 sq km).

Globally, wetland degradation is a major concern. The first-ever Global Wetland Outlook by the Ramsar Convention reveals that about 35% of the world’s wetlands were lost between 1970-2015, with annual rates of loss increasing from 2000. This is driven by megatrends like climate change, population growth, urbanization, and changing consumption patterns. Wetlands also face threats from pollution, unsustainable use, invasive species, disrupted flows from dams and sediment dumping from deforestation and soil erosion upstream.

In India, nearly 30% of natural wetlands were lost in the last three decades due to illegal construction, unsustainable urbanization, agricultural expansion, and pollution, according to Wetlands International South Asia. Mumbai lost the most wetlands (71%) from 1970 to 2014, followed by Ahmedabad (57%), Bengaluru (56%), Hyderabad (55%), Delhi and National Capital Region (38%), and Pune (37%).

Reasons for degradation of Wetlands:

Reasons for Wetland Degradation in India:

The growth of urban centers and increasing urban population has put pressure on wetlands and floodplains to meet water and food demand. The Kanwar lake in Bihar, Asia’s largest freshwater oxbow lake, has shrunk due to encroachment, as has Jammu and Kashmir’s Dal lake.

Intensification of agricultural activities has increased fertilizer consumption, leading to eutrophication of surface water bodies. An estimated 10-15 percent of nutrients added to soils through fertilizers eventually make their way into surface water systems.

Domestic wastewater treatment in Indian urban centers is low, with less than 31 percent treated, leading to discharge of untreated wastewater into natural water bodies. Industrial effluents also pose a major threat to the survival of wetlands. Bellandur Lake in Bengaluru city caught fire in May 2015 due to discharge of effluents.

Global climate change is expected to become an important driver of loss and change in wetland ecosystems. Wetlands located in high altitude and coastal areas, such as mangroves and coral reefs, are the most sensitive to climate change. India is estimated to lose about 84 percent of coastal wetlands and 13 percent of saline wetlands with climate change induced sea water rise of 1 meter.

Effective wetlands management involves maintaining all functions and characteristics specific to the wetland type. The program should protect, restore, manipulate, and provide for functions and values, emphasizing quality and acreage while promoting sustainable usage.

Wetland management requires intense monitoring and cooperation among various agencies, including those concerned with environment, soil, natural resource management, public interest groups, citizen groups, agriculture, forestry, urban planning and development, research institutions, government, and policy makers.

The management goals should aim to buffer wetlands from direct human pressures and maintain important natural processes that may be altered by human activities.

India has taken measures to conserve wetlands, such as:

1. Joining the Ramsar Convention in 1971. The convention aims to promote international cooperation and national action for the conservation and wise use of wetlands and their resources. 
2. India also launched the National Wetland Conservation Programme (NWCP) in 1985 to prevent further degradation of wetlands by enabling their conservation and wise use.
3. The Central Wetlands (Conservation and Management) Rules were first notified in 2010 to regulate and manage wetlands across the country. It also established the Central Wetlands Regulatory Authority (CWRA), whose term ended on 31 March 2015 and has not been reconstituted since.
4. Recognizing the significance of wetlands, the National Environment Policy 2006 calls for the development of a national inventory of wetlands and implementation of various policies and plans for their conservation and environmental impact assessment (EIA).
5. To enhance the skills of wetland managers, there is a proposal to upgrade the Wetland Research and Training Centre of Chilika Development Authority at Barkul, Odisha into the National Capacity Development Centre for Wetlands.
6. The National Mission for Clean Ganga has recently developed a toolkit for the management of wetlands and water bodies in urban areas, as well as assessing the challenges associated with rapid urbanization.

Sustainable Development Goals and Wetlands:

Wetlands play a crucial role in achieving several Sustainable Development Goals (SDGs). For instance, under SDG 1, which aims to end poverty, wetlands can help build resilience among poor and vulnerable communities. Wetlands provide potable drinking water, support agriculture and livestock rearing even during drought periods. The restoration of Waza Floodplain, a Ramsar site in Cameroon, helped to improve livelihoods, agricultural yields, grazing, and fishing, generating economic benefits of up to $2.3 million per year. Target 1.5 of SDG 1 is committed to reducing the exposure and vulnerability of the poor to climate-related events and other shocks by 2030. Loss of wetlands from climate change, anthropogenic causes or upstream large hydropower establishments can severely affect the livelihoods and way of life of local communities.

SDG 2 – End Hunger, Achieve Food Security and Improve Nutrition and Promote Sustainable Agriculture

Wetlands play an important role in providing water for irrigation and are a source of food protein for many communities around the world. For example, in Cambodia, fish from the Tonle Sap Lake and associated floodplains, which include two Ramsar Sites, provide 60%-80% of the animal protein consumed by local communities. Wetlands also support the growth of many edible species, contributing to food security for these communities.

SDG 5 – Achieve Gender Equality and Empower All Women and Girls

At COP13, a draft resolution was proposed to increase awareness among contracting parties about the linkages between gender equality and wetlands management. Women often have different levels of access to and control over natural resources, and their lack of information about how conservation and wise use of wetlands can affect their rights and customary use of wetland products and services.

SDGs 11: Make Cities and Human Settlements Inclusive, Safe, Resilient, and Sustainable

One way to reduce the risk of disasters in coastal areas is by using ecosystem-based infrastructure, known as EcoDRR. EcoDRR structures such as mangroves, coral reefs, and salt marshes offer natural protection against coastal hazards. They help to reduce the strength and height of waves, prevent storm surges, and absorb excess water. Implementing low-cost EcoDRR structures can help communities adapt to climate change while providing multiple ecosystem services. Wetlands, for instance, can serve as upstream retention basins to protect downstream cities from flooding.

SDGs 13: Take Urgent Action to Combat Climate Change and Its Impacts

Coastal ecosystems such as mangroves, coral reefs, salt marshes, and seagrass beds play a crucial role in mitigating climate change. These “Blue Carbon Ecosystems” sequester two to four times more carbon than terrestrial forests, which helps to prevent further greenhouse gas emissions. The carbon stored in wetland soil remains there for a long time, preventing further degradation and drainage of the wetlands ecosystem. Peatlands cover 3% of the Earth’s surface but hold twice as much carbon as the world’s forests. Preserving and restoring wetlands can help to build resilience and mitigate climate change, while their loss and mismanagement can intensify its impacts.