Many years ago, as a young person interested in nature, wetlands were one of the first ‘wild’ habitats I visited. I still remember the lush green colour of the reeds, the aroma of the water-saturated soil, and the cacophony of bird calls – an all-encompassing treat for the senses.
It was one of the first places where I felt like everything was interconnected. I remember connecting the dots in my brain, as textbook diagrams of the food web came alive in front of my eyes. The reeds, home to the birds; lotus buds, food for the coots; coots, food for the raptors; the raptors, pooping back into the water which in turn enriched the water for the weeds and thus continuing the cycle.
These initial experiences laid the foundation for my understanding of the different ecosystems I have visited since, as an enthusiastic naturalist and later as a filmmaker.
Wetlands are called ‘biological super systems’ because of their enormous productivity and their ability to support a remarkable level of biodiversity. In terms of the sheer number and variety of species that they support, the wetlands are as rich as rainforests.
What are wetlands?
Wetlands are varied ecosystems found in almost every corner of the world and are considered to be the most biologically diverse of all ecosystems.
Wetlands have the characteristics of both aquatic and terrestrial ecosystems. The defining feature is the presence of water for a significant period, which changes the soil, the microorganisms, the plant and animal communities, such that it functions in a completely different way from either aquatic or terrestrial habitats.
In its simplest form, a wetland can be described as a piece of land covered in shallow water.
Types of wetlands
I have always enjoyed exploring wetlands because of their sheer variety. I would be exploring a freshwater marsh with flamingos and other migratory birds in the morning, and within a few kilometres drive, I would be in an estuary watching Indo-Pacific estuarine dolphins. Many different kinds of wetlands can occur very close to each other and yet support completely different biota.
Under the Ramsar Convention, an intergovernmental treaty that provides the framework for the conservation of wetlands, wetlands can be classified into three broad types:
- Coastal wetlands
- Inland wetlands
- Human-made wetlands
In total, there are 11 kinds of coastal wetlands (like coral reefs, estuarine waters, intertidal mud flats), 19 kinds of inland wetlands (like rivers, freshwater lakes, marshes) and 9 kinds of human-made wetlands (like aquaculture ponds, reservoirs).
Why are wetlands important?
At first glance, wetlands might not seem like they hold much importance. They do not have the awe and grandeur of a rainforest ecosystem, but there is more to them than what meets the eye. There are two levels to this ecosystem, one above the water which we see and one below which we do not.
Wetlands cover only a small percentage of the earth’s surface, yet they are essential systems – they are the arteries and veins of our planet. All the different types of wetlands put together provide very beneficial ‘services’ to humans, and these services are as varied as the wetlands themselves.
– Water Supply
Wetlands, at their core, are pieces of land saturated with water. They are our planet’s water tanks – they provide drinking water, water for irrigation, and water for our industries which power the world’s development.
- About 2 lakh farmers in Kerala depend on the Vembanad Kol wetland for irrigation
- About 6 lakh people depend on Bhopal’s lakes for water supply
Wetlands are enormously productive; indigenous people living beside wetlands depend on it for wild game/fish and most freshwater lakes/rivers provide enormous economic value to people living on their banks. In fact, human-made wetlands power the world’s food production, through fisheries, paddy fields and the like. Human-made wetlands are often modified natural wetlands, known as converted wetlands. But the total economic value of unconverted wetlands is often greater than converted wetlands.
- Manipur's Loktak Lake, the largest freshwater lake in northeast India, provides livelihood for more than 1 lakh fisherfolk
- Odisha's Chilika Lake provides livelihood for more than 2 lakh fisherfolk
– Water Purification
Wetlands play a major role in treating and detoxifying wastewater. Wetland soil is thick and multilayered. The water entering a wetland slowly percolates down into the already saturated soil, where the excess nutrients get absorbed by plants and microorganisms after which it enters the water table below.
- The East Kolkata Wetlands (a Ramsar site) is a remarkable example of sewage treatment by a wetland ecosystem
- Constructed wetlands are being used in several cities to treat sewage water
– Climate Change Mitigation
Climate change is one of the most important issues affecting our lives today, and wetlands are one of the most important ecosystems that can help fight it. Sea level rise and increases in storm surges will result in erosion, increased salinity of estuaries and freshwater aquifers, altered tidal ranges in rivers and bays, changes in sediment and nutrient transport, and increased coastal flooding. Wetlands, such as mangroves and floodplains, play a critical role in the physical buffering of climate change impacts.
Wetlands also play an important role in flood control. They are considered to be a natural capital substitute for conventional flood control investments such as dykes, dams, and embankments. There are natural systems in place in a wetland ecosystem which allows for the water to dissipate and help lessen the impacts of flooding by absorbing water and reducing the speed of flow. During periods of flooding, they trap suspended solids and nutrient load.
- A study on the Bhitarkanika mangrove ecosystem in Orissa, the second largest mangrove forest on the India mainland, estimated that the loss incurred per household was greatest (US$ 153.74) in the village that was not sheltered by mangroves and lowest (US$ 33.31) in the village that was protected by mangrove forests (Badola and Hussain, 2005)
– Climate Regulators
Globally, wetlands represent just three per cent of the total land area but they sequester 30 per cent of all soil carbon. Wetlands regulate climate change through carbon sequestration, whereby it releases a major proportion of fixed carbon in the biosphere.
This decomposition of organic matter in the wetlands releases large amounts of methane into the atmosphere, but this is a natural process, and the amount of methane released into the atmosphere changes depending on the water and soil temperature. Disrupting this natural process is what contributes to climate change negatively
- Wetlands sequester carbon through high rates of organic matter inputs and reduced rates of decompositions (Pant et al, 2003). Wetland soils may contain as much as 200 times more carbon than its vegetation
- Carbon sequestration potential of restored wetlands (over 50 year period) comes out to be about 0.4 tonnes C/ha/year (IPCC, 2000)
- Mangroves are able to sequester about 1.5 tonne C/ha/year
Threats to wetlands
My observation of wetland degradation near cities, over the years, has been that most cities don’t consider wetlands as ecosystems of value, especially marshlands, swamplands, small ponds and lakes. They are always viewed as wastelands, used to dump solid or liquid waste or as free space to expand and construct buildings.
The human modification of our landscape has been the foremost factor in wetland loss and degradation. Studies estimate that up to half of the world’s wetlands have been lost due to human activities (Mitsch and Gosselink 2000). Land-use land cover (LULC) changes can result in direct ecosystem loss as well as fragmentation, causing a decrease in wetland quality and an increase in wetland stress.
Wetland loss directly results in the demise of flora and fauna populations in addition to the loss of ecosystem services performed such as ground-water recharge, nutrient cycling, heavy metal retention, and flood control. The destruction or draining of wetlands also leads to colossal amounts of methane trapped within the soil to be released into the atmosphere. The effect of methane as a greenhouse gas is 25 times worse than carbon dioxide in our atmosphere.
A survey by the Wildlife Institute of India reveals that 70-80% of individual freshwater marshes and lakes in the Gangetic floodplains have been lost in the last five decades. At present, only 50 per cent of India’s wetlands remain. They are disappearing at a rate of 2-3 per cent every year. Indian mangrove areas have been halved almost from 700,000 hectares in 1987 to 453,000 hectares in 1995 (Sustainable Wetlands, Environmental Governance-2, 1999).
– Reclamation and encroachment
Marshlands, swamplands and mangroves are the types of wetlands that occur close to most big cities. If dumping of garbage is not one of the reasons for their destruction, then it is the illegal encroachment of these habitats. Even though most cities have urban plans that restrict construction on wetlands, a surprising number of cities have an ever-increasing number of gated communities or villas with a ‘lake view’. Ironically, they are the first houses to go underwater when there is a slightly heavy downpour.
In rural areas, dry lake beds are converted into fields during the summer. Similarly, large areas of wetlands are cordoned off for the commercial production of salt, which changes the characteristics of the land permanently.
- In Andhra Pradesh, about 34,000 hectares of Kolleru Lake's water spread area has been reclaimed for agriculture in recent years
- Between 1973 and 2007, the Greater Bengaluru Region lost 66 wetlands with a water spread area of around 1,100 hectares due to urban sprawl (Ramachandra and Kumar, 2008)
- Out of 629 water bodies identified in the National Capital Territory (NCT) of Delhi, as many as 232 water bodies cannot be revived on account of large scale encroachments (Khandekar, 2011)
- In 1968, Kolar district had 35,783 tanks, which reduced to 2,095 in 2012 (Karnataka Gazetteer)
- In Jammu and Kashmir, Wular lake and Mirgund wetlands have been reduced to one-third of their original size.
Wetlands are used as dump yards for plastics, toxic chemicals and other non-biodegradable wastes. These fragile ecosystems which depend on well-balanced water chemistry are destroyed entirely, and the birds that depend on fish and plant matter from them become second in line to the adverse effects of pollution.
When these city-area-sized dumps become unmanageable, they are set on fire and the smoke that is generated from burning tons of unsorted garbage takes to the air and spreads carcinogenic fumes everywhere. The groundwater also gets contaminated by the medical waste and industrial waste that is illegally dumped here.
East Kolkata Wetlands, Mumbai MMRDA wetlands, Chilika, Loktak, Kashmir wetlands are all falling prey to excessive pollution. While Bengaluru wetlands have been in the news for privatisation and pollution, they have touched a new low by foaming over and even catching fire. As mentioned by several CAG Reports, including CAG report on Water Pollution, 2011, there is no baseline data on water quality of wetlands, nor monitoring of their water quality
Most wetlands are related to river systems and are impacted profoundly due to damming/ water abstraction. Wetlands like Renuka Wetlands (proposed dam), Keoladeo Ghana Sanctuary, Upper Ganga Ramsar Site, Nal Sarovar Bird Sanctuary, Loktak Lake, Chilika Lake, Vembanad Kole, etc. are severely impacted by dams which are affecting water and silt flow.
The Convention on Wetlands of International Importance holds the unique distinction of being the first modern treaty between nations aimed at conserving natural resources. The signing of the Convention on Wetlands took place in 1971 at the small Iranian town of Ramsar. Together they are known as the Ramsar Convention.
The Convention's mission is “the conservation and wise use of all wetlands through local and national actions and international cooperation, as a contribution towards achieving sustainable development throughout the world.”
Conservation and wise use of wetlands lie at the heart of sustainable development. The Ramsar Convention focuses on the three pillars: the wise use of wetlands, the designation and conservation of Ramsar sites, and fostering transboundary management. Reversing the trend of degradation and loss is critical.
Future of wetlands
Wetlands, unlike forests, is an ecosystem we are all familiar with. Almost everyone would have encountered a small pond, lake or marsh in their lives, even in urban landscapes, yet we are unaware of its beauty or its workings.
These complex ecosystems are currently facing pressure from numerous sources, and the solutions for its conservation are also complex and require multiple people from different departments to work together, to make an impact.
The importance of conserving wetlands for our very own existence cannot be overstated, but collectively as a species, we are failing to see how everything in our world is connected.
My hope as a filmmaker would be to create films that educate people about nature and make people care about the future of our planet, for tomorrow might be the day we finally decide to wake up and save ourselves and in the process save our wetlands and our environment.
Watch Sripad's journey here: