Just as forests are called the ‘lungs of the earth’, wetlands are the ‘kidneys’ that regulate water and filter waste from the landscape. Wetlands include mangroves, peatlands and marshes, rivers and lakes, deltas, floodplains and flooded forests, rice-fields, and even coral reefs.
Wetlands exist in every country and in every climatic zone, from the polar regions to the tropics, and from high altitudes to dry regions. In India, around 4.63% of the geographical area is wetlands. A total of 757,060 wetlands have been mapped in the country.
But, why are wetlands important? What are its benefits?
Wetland ecosystems support a host of animal and plant life and they are critically important for the survival of humans too, from the mitigation of Climate Change to the protection of human settlements from floods. If we protect wetlands, we also protect our planet and ourselves. But sadly, 50% of the world’s wetlands have been destroyed. Without suitable wetland habitat, many species could soon be homeless. Let us explore the benefits of wetlands in detail:
1. Wetlands purify our water
Wetlands are great filters! They trap sediments and remove pollutants, which helps to purify water. This certainly beats expensive, human-made filtration systems.
2. Wetlands store our water to ensure supply during dry periods
Wetlands work like giant sponges. They store water and then slowly release it, and this helps to deal with dry seasons with little rainfall.
3. Wetlands can prevent floods
When rivers burst their banks, wetlands can store the excess water, and slow it down so it distributes more evenly over a floodplain. The roots of trees and other vegetation also help slow the speed of flood waters.
4. Wetlands recharge groundwater
In the past, city planners either filled in wetlands areas or dammed them, adding pipes that would lead the water to the ocean as fast as possible. But now we know that wetlands allow water to soak into the ground, and to replenish the natural ground-water supply.
5. Wetlands help to control erosion
Sediments are also trapped by wetlands. In a semi-arid country like South Africa, the role of wetlands in trapping sediments, before the sediment-laden water joins a river course and just washes away, is really useful.
6. Wetlands provide shelter for juvenile fish
Fish larvae and fish fry (juveniles) use the calm, shallow waters of wetlands as a nursery.
7. Wetlands provide homes for animals and plants
Biodiversity is high around wetlands habitats. These areas provide food and shelter for many animals, in particular bird species such as herons, spoonbills and flamingos, and amphibians such as frogs.
8. Wetlands provide food for livestock
Wetlands provide good areas for grazing, and the variety of grasses, along with a supply of running water, can be beneficial to farming livestock.
9. Wetlands protect biodiversity
Many different kinds of creatures depend on wetlands - and on each other. The insects that are attracted to the plants provide food for other animals like fish, frogs and birds, who in turn attract other predators. The biodiversity of wetlands has produced some incredible specialist species that are only found in these habitats.
10. Wetlands provide locations for recreation
Wetlands provide people a place to visit, where they can enjoy nature walks, picnics, birding, fishing or even sailing. As more people flock to cities, these recreational spaces in nature become even more valuable.
During COP13 the Ramsar Convention introduced the Wetland City Accreditation, which recognizes 18 cities that have taken exceptional steps to safeguard their urban wetlands. These pioneer cities will serve as examples and inspire deliberate actions for other cities towards sustainable urbanization.
Currently in India, 47 wetlands, with a surface area of over a million hectares are designated as wetlands of international importance under the Ramsar Convention. One of the most important ones in this list is the 55 acre East Kolkata Wetlands (EKW). It is the world’s only fully functional organic sewage management system. These wetlands are Kolkata’s free sewage remediation works, a fertile aquatic garden and, most importantly, a natural flood defence for the low-lying city.
The capital, Delhi, has identified 1,043 water bodies but none are notified. This, however, could soon change, with the Capital expected to notify 10 major lakes and water bodies as wetlands by the end of March. The Delhi State Wetland Authority (DSWA) is expected to release a draft notification for each water body under the Wetlands (Conservation and Management) Rules of 2017.
Down to Earth is Science and Environment fortnightly published by the Society for Environmental Communication, New Delhi. We publish news and analysis on issues that deal with sustainable development, which we scan through the eyes of science and environment.