Wetland Ecosystem

 

Introduction

  • A wetland is an area of land that is either covered by water or saturated with water.
    • The water is often groundwater, seeping up from an aquifer or spring.
    • A wetland’s water can also come from a nearby river or lake.
    • Seawater can also create wetlands, especially in coastal areas that experience strong tides
  • The Ramsar Convention on Wetlands defines wetlands as “areas of marsh, fen, peat land 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 tide does not exceed six meters.”
  • These comprise areas that transition between terrestrial (land) areas and aquatic (water) areas.
  • These are a distinct ecosystem that is flooded by water, either permanently (for years or decades) or seasonally (for weeks or months)
  • Wetlands exist in many kinds of climates, on every continent except Antarctica. They vary in size from isolated prairie potholes to huge salt marshes.
  • The West Siberian Lowland, Amazon River Basin, and Hudson Bay Lowland are among the largest wetlands in the world.
    • The world’s largest protected wetland is Llanos de Moxos, located in Bolivia. It is more than 17 million acres

 

Major kinds of Wetlands

  • Swamps
    • A swamp is a wetland permanently saturated with water and dominated by trees, and are of two types
      • Freshwater Swamps
        • Freshwater swamps often form on flat land around lakes or streams, where the water table is high and runoff is slow
        • Water-tolerant plants, such as cattails, lotus, and cypress, grow in the swamp’s wet soil. These plants are key to maintaining the swamp’s ecosystem
        • Freshwater swamps are common in tropical areas near the Equator.
      • Saltwater Swamps
        • Formation of these swamps begins with bare flats of mud or sand that are thinly covered by seawater during high tides.
        • The brackish water of saltwater swamps is not entirely seawater, but not entirely freshwater, either
        • The Sundarbans, a saltwater swamp in India and Bangladesh, has the largest mangrove forest in the world
  • Marshes
    • North and south of the tropics, swamps give way to marshes.
    • These wetlands form a flat, grassy fringe near river mouths, in bays, and along coastlines. Many are alternately flooded and exposed by the movement of tides.
    • Marshes are often divided into
      • Freshwater Swamps
        • Freshwater marshes, often found hundreds of kilometers from the coast, are dominated by grasses and aquatic plants. These marshes often develop around lakes and streams.
        • Many freshwater marshes lie in the prairie pothole region of North America, the heart of which extends from central Canada through the northern Midwest of the United States.
      • Saltwater Marshes
        • Salt marshes are some of the richest ecosystems for biodiversity. Dominated by grasses, they provide food and shelter for algae, fungi, shellfish, fish, amphibians, and reptiles.
        • A few mangrove trees may dot saltwater marshes, but they are dominated by grasses and a layer of algae called an algal mat. This algal mat is home to many insects and amphibians.
  • Bogs
    • Swamps and marshes are generally found in warm climates. Bogs are more common in cold or even Arctic areas in North America, Europe, and Asia.
    • Bogs are often called moors or fens in Europe, and muskegs in Canada.
    • Like many wetlands, bogs develop in areas where the water table, or the upper surface of underground water, is high
    • The oldest, partially decayed vegetation at the bottom of the bog forms a thick, spongy mat called peat.
    • Unlike other wetlands, bogs usually are not agriculturally fertile. The amount of acid in the soil and water is generally higher than that in swamps or marshes.
    • Because of the limited species of plants, bogs do not have the biodiversity common in other types of wetlands

 

Significance of Wetlands

  • Wetlands are particularly important providers of all water-related ecosystem services
    • They regulate water quantity, groundwater recharge, and can contribute to regulating floods and the impacts of storms.
    • Wetlands also help in erosion control and sediment transport, thereby contributing to land formation and increasing resilience to storms.
    • All these ecosystem services improve water security, including security from natural hazards and climate change adaptation
  • Wetlands are productive areas for plant life, animals and wetland agriculture
    • Compared to many other ecosystems, wetlands are one of the most productive habitats in the world.
    • With greater species diversity nutrient recycling and niche specialization than most other ecosystems.
  • Wetlands are the major habitat for most of the world’s waterbirds and key habitat for migratory species
    • Almost all of the world’s waterbirds use wetlands as feeding and breeding grounds.
    • Migratory waterbirds use wetlands throughout their range which can sometimes literally be from pole to pole.
    • The feeding, breeding and stop-over areas across and between continents that migratory birds depend on requires coordinated wetlands conservation efforts among many nations
  • Wetlands are an important source of food
    • Well-managed rice paddy systems, for example, produce not only rice but also co-benefits from rice-associated biodiversity, such as highly nutritious food in the form of fish, molluscs and crustaceans.
    • Wetlands also support the multitude of biota that helps sustain rice productivity through supporting nutrient cycling and pest and disease regulation. The entire production of inland capture fisheries and most coastal fisheries is derived from wetlands, as is most aquaculture production
  • Wetlands have high recreational, historical, scientific, and cultural values
    • Wetlands have played an important part in human development and are of significant religious, historical or archaeological value to many cultures around the world.
    • They are also often inviting places for popular recreational activities including hiking, fishing, bird watching, photography and hunting

 

Wetlands in India

  • Globally, wetlands cover4 per cent of the geographical area of the world
  • In India, according to the National Wetland Inventory and Assessment compiled by the Indian Space Research Organisation (ISRO), wetlands are spread over 1,52,600 square kilometres (sq km) which is 4.63 per cent of the total geographical area of the country
    • Of the 1,52,600 sq km, inland-natural wetlands account for 43.4% and coastal-natural wetlands 24.3%.
    • Rivers/streams occupy 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.
  • In state-wise distribution of wetlands, Gujarat is at the top with 34,700 sq km (17.56 percent of total geographical area of the state), or 22.7 percent of total wetlands areas of the country thanks to a long coastline. It is followed by Andhra Pradesh (14,500 sq km), Uttar Pradesh (12,400 sq km) and West Bengal (11,100 sq km)
  • Ramsar Sites in India
    • India’s tally of 49 designated wetlands spread over 10,936 sq km in 18 states and two Union Territories is the largest network of Ramsar Sites in South Asia
    • Of the 49 sites, 10 are in UP, 6 in Punjab, 4 each in Gujarat and Jammu and Kashmir, 3 each in Himachal Pradesh and Kerala, 2 each in Haryana, Maharashtra, Odisha, West Bengal, Rajasthan and one each in Andhra Pradesh, Assam, Bihar, Ladakh, Manipur, Tamil Nadu, Tripura, Uttarakhand and Madhya Pradesh.

Wetland Degradation

  • Global Wetlands Outlook paints alarming picture of decline in world’s most valuable ecosystems
    • The report reveals that World’s wetlands disappearing three times faster than forests
  • Approximately 35 per cent of the world’s wetlands were lost between 1970-2015 with annual rates of loss accelerating from 2000, according to the first-ever Global Wetland Outlook of the Ramsar Convention
  • Losses have been driven by megatrends such as climate change, population increase, urbanization, particularly of coastal zones and river deltas, and changing consumption patterns that have all fuelled changes to land and water use and to agriculture.
  • Further, the wetlands face threats from pollution, unsustainable use, invasive species, disrupted flows from dams and sediment dumping from deforestation and soil erosion upstream

 

Wetland Degradation: India

  • Present status
    • According to estimates by Wetlands International South Asia, nearly 30% of the natural wetlands in India have been lost in the last three decades mainly to illegal construction, unsustainable urbanisation, agricultural expansion and pollution
    • Mumbai has lost maximum wetlands (71%) — from 1970 to 2014.
      • Other major cities that faced wetland loss include Ahmedabad (57%), Bengaluru (56%), Hyderabad (55%), Delhi and National Capital Region (38%), and Pune (37%)
  • Reasons
    • Urbanization and land use changes
      • During the 90 year period from 1901 to 1991, the number of urban centres doubled while urban population has increased eightfold. This magnitude of growth exerted tremendous pressure on wetlands and flood plain areas for meeting water and food demand of growing population
      • For example, the Kanwar lake in Bihar, Asia’s largest freshwater oxbow lake, has shrunk to one-third of its size due to encroachment, much like Jammu and Kashmir’s Dal lake.
    • Agricultural residues
      • As a result of intensification of agricultural activities over the past four decades, fertilizer consumption in India has increased from about 2.8 million tonne in 1973–1974 to 28.3 million tonne in 2010–2011
      • As per estimates, 10–15 percent of the nutrients added to the soils through fertilizers eventually find their way to the surface water system. High nutrient contents stimulate algal growth, leading to eutrophication of surface water bodies
    • Municipal and Industrial pollution
      • Less than 31 percent of the domestic wastewater from Indian urban centres is treated, compared to 80 percent in the developed world, which is largely discharged in the natural water bodies such as streams and rivers
      • These along with untreated industrial effluents have become a major threat to the survival of wetlands
      • For instance, the Bellandur Lake in Bengaluru city was ‘on fire’ in May 2015 due to the discharge of effluents (especially nutrient rich foams) by the surrounding industries.
    • Climate Change
      • In 2007, the UNESCO estimated that Global climate change is expected to become an important driver of loss and change in wet-land ecosystem. These findings are important for India which has been experiencing the flood-drought-flood cycle for the last 2 decades
      • As per a study, wetlands located in high altitude as well as coastal areas, like mangroves and coral reefs, are some of the most sensitive classes that will be affected by climate change.
      • As per an estimate, India will lose about 84 percent of coastal wetlands and 13 percent of saline wetlands with climate change induced sea water rise of 1 metre
    • Other threats include
      • Wetlands are impacted profoundly by damming and water abstraction: Keoladeo Ghana Sanctuary, Loktak Lake, Chilika Lake, Vembanad Kole are among those severely impacted by dams that affect water and silt flows.
      • immersion of idols and religious ritual waste
      • introduction of exotic species
      • encroachments and unregulated aquaculture (e.g. Kolleru lake) backed by Bureaucrats-Politicians-Businessmen nexus
      • Un-planned urbanization and development projects

 

Wetlands Management

  • Management is the manipulation of an ecosystem to ensure maintenance of all functions and characteristics of the specific wetland type
  • The wetland management program generally involves activities to protect, restore, manipulate, and provide for the functions and values emphasizing both quality and acreage by still advocating sustainable usage of them
    • Management of wetland ecosystems requires an intense monitoring, increased interaction and co-operation among the various agencies (state departments concerned with environment, soil, natural resource management, public interest groups, citizen groups, agriculture, forestry, urban planning and development, research institutions, government, policy makers, etc)
    • Such management goals should not only involve buffering wetlands from any direct human pressures that could affect the wetlands normal functions, but also in maintaining important natural processes that operate on them that may be altered by human activities
  • The principles in Management strategies that can be incorporated are as follows:
    • The management strategies should involve protection of wetlands by regulating inputs using water quality standards (WQS) promulgated for wetlands and such inland surface waters to promote their normal functioning from the ecosystem perspective, still deriving economic benefits by sustainable usage.
    • Creation of Buffers zones for Wetlands protection: Creating buffer zones limiting anthropogenic activities around the demarcated corridor of the wetland could revive its natural functioning
    • Community support: Wetland management, restoration or conservation of wetland ecosystem requires an integrated, broad-based inter-agency partnership all working towards a common goals involving the educational institutions, forest department, Bangalore Development Authority (BDA), City Corporation, Irrigation department, Public Works Department (PWD) and Pollution Control Board for a successful conservation and management of wetlands.
    • Roping in young talent
      • Wetlands requires a collaborated research involving natural, social and inter-disciplinarian study aimed at understanding the various components, such as, monitoring of water quality, socio-economic dependency, biodiversity and other activities as an indispensable tool for formulating long term conservation strategies
      • This needs multidisciplinary-trained professionals in educating the essence of wetland importance involving the local school, colleges and research institutions. Initiate educational programs aimed at raising the levels of public awareness and comprehension of aquatic ecosystem restoration goals, and methods
    • Regulatory bodies: An interagency regulatory body comprising personnel from departments involved in urban planning (City Development Agency) resource management (Forest department, Fisheries, Horticulture, Agriculture, etc.), and regulatory bodies such as Pollution Control Board (PCB), local citizen groups, research organisations and NGOs  would help in evolving effective wetland programs covering significant components of the watershed, that needs a co-ordinated effort from all agencies and organisations involved in programs affecting the health of wetland ecosystems directly or indirectly

 

Measures in India for Wetland Conservation

  • Ramsar Convention
    • The convention is named after Ramsar in Iran in which the convention was ratified in 1971. The convention is aimed at augmenting national action and international cooperation for the conservation and wise use of wetlands and their resources
  • National Wetland Conservation Programme (NWCP)
    • It was launched in 1985 to enable conservation and wise use of wetlands in the country so as to prevent their further degradation.
  • The Central Wetlands (Conservation and Management) Rules
    • They were notified for the first time in 2010 for better management and regulation of wetlands across the country. It saw the formation of Central Wetlands Regulatory Authority (CWRA) whose term ended on 31 March 2015 and it wasn’t reconstituted since then.
  • National Environment Policy 2006
    • Recognising the importance of wetlands, it calls for developing a national inventory of such wetlands and implementing a wide spectrum of policies and plans for wetland conservation and their environmental impact assessment (EIA)
  • Capacity Building
    • In order to increase the capacity of wetland managers, up gradation of the existing Wetland Research and Training Centre of Chilika Development Authority at Barkul, Odisha into the National Capacity Development Centre for Wetlands is under consideration
  • National Mission for Clean Ganga
    • The National Mission for Clean Ganga in January 2021 formulated a toolkit for management of wetlands and water bodies in urban areas as well as studying the concerns of rapid urbanisation
  • Master Plan Delhi 2041
    • The Delhi Development Authority invited public comments on Master Plan Delhi 2041 (MPD 2041) to protect and develop an integrated network of ‘green and blue assets’ of Delhi to maintain the biodiversity and microclimate of the capital

 

What more could be done in India in this perspective?

  • Mainstreaming wetlands ecosystem services and biodiversity into our developmental policies and urban planning processes, including climate change mitigation, is the pressing need of the hour
  • Mega urban schemes like Smart Cities Mission and Atal Mission for Rejuvenation and Urban Transformation need to add the aspects of sustainable management of wetlands.
  • There is also a need for more scientific data, imagery, maps and other relevant tools to provide knowledge on the status of wetlands.
  • There is also a need for stronger enforcement of rules. For example, the National Plan for Conservation of Aquatic Ecosystems and the Wetlands Conservation and Management Rules, 2017 (updated in 2020), have had limited impact as regulatory bodies like the Central Wetland Regulatory Authority only have advisory powers.
  • Further, Awareness is the first step towards protection, which requires a collaborated effort from all stakeholders

 

Wetlands and SDGs

  • The role of Wetlands in achieving SDGs can be assessed as follows:
    • SDG 1 End Poverty in All Its Forms Everywhere
      • Building resilience of the poor & vulnerable is one of the targets under this goal & one where the role of wetlands can be clearly illustrated.
      • Wetlands provide a clean potable drinking source of water, (Even during drought period) for cattle, agriculture & human consumption.
      • Example: In Cameroon, restoration of Waza Floodplain, a Ramsar site helped to reinstate the flooding regime. It resulted into an improvement of gross livelihoods; agricultural yield, grazing & fishing thus generating economic benefits estimated at $2.3 Million per Year.
      • Target 1.5 of SDG 1 is committed to build resilience of the poor & those in the vulnerable situations & reduce their exposure & vulnerability to climate-related extreme events & other economic, social & environmental shocks & disasters by 2030.
        • Loss of wetlands whether it is from climate change, upstream large hydropower establishments or anthropogenic causes severely affect the way of life & livelihoods of local surrounding communities
    • SDG 2 End Hunger, achieve food security & improve nutrition & promote sustainable agriculture
      • Wetlands store an enormous mass of water to be utilized to irrigate land under cultivation. Wetlands are an important source of food protein to many people around the world.
      • In Cambodia, fish from large Tonle Sap Lake & associated floodplains which include two Ramsar Sites, provide communities with 60%-80% of their animal protein. Wetlands are the home of many edible species which provide food security to the local communities
    • SDG 5 Achieve Gender Equality & Empower All Women & Girls
      • COP 13 considers a draft resolution which confers a process to increase awareness among contracting parties on the linkages between gender equality & wetlands management.
      • Women have different access to & control over natural resources & information about how conservation & wise use shapes the way in which wetlands are managed, affecting their rights & customary uses wetlands products & services.
    • SDGs 11 Make Cities & Human Settlements Inclusive, Safe, Resilient & Sustainable
      • Ecosystem based Disaster Risk Reduction (EcoDRR) infrastructure such as mangroves, coral reefs, salt marshes provide low cost natural immunity to coastal regime by reducing wave height & potential strength, reducing storm surges & absorbing some of the excess water.
      • These low cost EcoDRR structure provide not only community resilient against water related risks but enabling communities to better adapt to climate change, & provide multiple ecosystem services. Wetlands serve as upstream retention basins protecting downstream cities from flood risk.
    • SDGs 13 Take Urgent Action to Combat Climate Change & Its Impacts
      • Coastal ecosystems in particular to mangroves, coral reefs, salt marshes, sea grass beds sequester two to four times carbon than terrestrial forests & these ‘Blue Carbon Ecosystem’ play a significant role in climate change mitigation.
      • This carbon is stored for a persistent period in wetland soil preventing further degradation, drainage & depletion of wetlands ecosystem which is critical to prevent further Green House Gas Emissions/GHGs.
      • Peatlands contribute 3% of the earth’s surface but they hold twice as much carbon as world’s forests. Losing & mismanaged wetlands contribute to intensify climate change while restoring & conserving them shall help building resilience & climate change mitigation.