The World Wetlands Day was celebrated on February 2, marking the signing of the convention on wetlands or better known as the Ramsar Convention, from the town in Iran where the convention was adopted in 1971. This year the theme is Wetlands for the future – Sustainable Livelihoods.
What are wetlands? The comprehensive definition comes from the Ramsar Convention and goes thus “Wetlands are 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 tide does not exceed six metres.”
In short, wetlands can be understood to be swampy or marshy land subject to permanent or temporary flooding by water.
Wetlands harbour a tremendous biodiversity of plants and animals. They are also called the kidneys of the world because they clean up water as a natural function.
In our cities all our ancient tanks are essentially wetlands. They would store water for irrigation purpose for some time of the year and would become dry for the summer months.
What do wetlands mean for cities? Cities can be seen as vast flows of nutrients and water. The cities’ thirst is satiated by pumping water from the hinterland and after it is used in individual homes this used water, carrying loads of nutrients, flows out in sewage pipes and storm-water drains, often ending up in our lakes and rivers.
One way to deal with these flows of nutrients in water is to treat them using conventional sewage treatment plants. However, most old waste-water treatment plants do not remove the nitrates and phosphates present in the water. By allowing this treated waste-water to flow into constructed wetlands it is possible to create flourishing habitats for birds and animals as well as fishes. Constructed wetlands with plants like water hyacinths and duckweed can remove heavy metals, nitrates and phosphates from water.
They can be perfect places to raise fish and provide livelihood for fishermen as well as add nutrients to the city dwellers’ diet.
As can be seen in the tanks of Puttenahalli, Yelahanka, Kaikondarahalli, Rachenahalli and Jakkur for example, birds and water fowls abound in these ecosystems.
By integrating constructed wetlands into the system of managing waste-water in our cities, great benefits can follow. It is important that the wetlands be managed and regular harvesting be done of the plants that grow so that excess nutrients are removed and the system does not eutrophy or decay.
In the imagination of people tanks are seen almost akin to swimming pools with clean water. In nature, however, water strives to become land and the wetland is an intermediate process.
This year the theme for world wetland day suggests four steps:
Visit a wetland
Find out how wetlands are essentially for livelihoods
Learn how communities use wetlands wisely
..and for the youth …enter a photo contest
So, do plan a visit to the lakes mentioned if you are in Bengaluru or find a nearest wetland in the towns and cities that you are in. Also find more information on www.worldwetlandsday.org and move forward on the path to water wisdom.
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