A to Z guide to Bengaluru’s lakes
A to Z guide to Bengaluru’s lakes By Labonie Roy, Mongabay-India and Citizen Matters Download PDF Indian cities are not typically imagined to be biodiversity hotspots and aspects of urban ecology often get missed in public conversations about the city. Apart from being recreational areas, Bengaluru’s water bodies and their bordering spaces, are home to biodiversity, sources of livelihood, and much more. In this set of illustrations, we examine the components of Bengaluru’s lakes and get a glimpse of what lies beneath the concrete layers and dense human population in India’s metros. Every artwork has elements of household and construction waste that the artist found in her neighbourhood in Bengaluru. Look closely and see if you can spot them. Why are many lakes in Bengaluru green? It is because they are blanketed by microscopic plants that contain chlorophyll, called algae. But are they good or bad for the lakes? Fixers of carbon, generators of biomass and inconspicuous primary producers in the ecosystem – algae are vital for healthy lakes. These microorganisms convert water and carbon dioxide to sugar, through the process of photosynthesis. This generates oxygen as a by-product. Zooplankton, small fish and other aquatic creatures consume algae, launching the magical process of the food cycle. But too much of a good thing can also be a bad thing. Excess algae, especially the harmful types, can be detrimental to the lake, indicating pollution and high amounts of nutrients like nitrogen and phosphorus which cause eutrophication. The overgrowth of algae can also cause ‘dead zones’ in the lakes, where aquatic life cannot survive because of insufficient oxygen. In Bengaluru, the discharge of industrial waste and untreated sewage, algal blooms (rapid increase in the population of algae) occur. The water then gets polluted, discoloured, clogged and gives out a certain odour. A lake’s beauty comes from the biodiversity it hosts, its calm waters and views. But in recent times, ‘beautification’ in the urban context, is associated with artificial structures and concretisation. Landscaping, boating, paved pathways and restricted entry through ticketing are some of the elements of the brick and mortar beautification of Bengaluru’s lakes, while activists call for use of the funds for regular rejuvenation actions like desilting, de-weeding and sewage management. Environmental activists argue that instead of solely focusing on the superficial beautification of water bodies, the plan should be to restore them and maintain them. Because, by simply beautifying the lakes, the development projects end up shrinking the size of the lakes, by destroying the wetlands surrounding the lake and also have a deleterious impact on the health of the lakes. Excess concretisation and planting non-native, instead of native trees and plants typically found around the lake, affects biodiversity. Round, light-weight boats – coracles – are a reminder of Bengaluru of yore. Before a joyride on a coracle became a tourist attraction, these boats were widely used by fisherfolk for traditional and sustainable fishing. Fishing communities used the coracle to spread nets and harvest fish. The practice is less popular now as urbanisation has changed the landscape and fishing practices have been modified too, though fishers still use coracles made from synthetic materials instead of natural materials. The coracle remains a symbol of the journey of Bengaluru lakes from fishing hotspots to recreational sites. Buzzing around Bengaluru lakes, dragonflies are often on a hunt for insects on the lake. These speedy fliers spend most of their life near water bodies and are part of the lake ecosystem in Bengaluru. The larvae live in water and the adults are terrestrial and find their food by the water. Millions of dragonflies migrate thousands of kilometres across the sea each year, from southern India to Africa. Biologists claim that this could be the longest migration of any insect. Their presence is very important for humans too. Being aerial predators, they catch unwanted insects like mosquitoes and feed on them. They also catch midges, butterflies, moths and bees. Effluent is wastewater containing a high amount of toxins that flow out of factories, industries or sewer plants, directly into water bodies. Effluent discharge into freshwater ecosystems like lakes, affects the water, reducing its oxygen content and making it unusable. It also affects the soil that is fed by this toxic water. The poor water and soil quality in turn are harmful to plant and animal life that survive on them. Effluents are also one of the elements of the froth – bubbles of water that form a white layer on lakes. Due to effluents, non-biodegradable detergents and other toxins present in the lake, the lakes belch out froth. Bengaluru’s Bellandur lake, infamous for its pollution, has been found covered with a huge amount of smelly froth. The fluffy white frothy layer on a lake is actually a sign that the lake is unhealthy and needs immediate restoration attempts. Groundwater is the water present beneath the Earth’s surface. In Bengaluru, one of Asia’s fastest-growing cities, groundwater is not available in abundance to meet the water demand. Bengaluru’s annual average rainfall is 970 mm. Well, that seems sufficient to meet our needs! Yes, but in many parts of the city, the groundwater is contaminated due to sewage, industrial waste and soil pollution, making it unusable/unsafe. Conserving groundwater needs action by both the citizens and the government who together need to ensure that groundwater recharge is carried out at scale across the city. Public spaces are what give character to a city. Bengaluru has evolved to become synonymous with lakes because of how successfully people utilise the space. Lakes in Bengaluru are reminders of a childhood spent in the company of nature. The greenery, the water and the biodiversity in and around the water source, people in their calmest moods, make the time spent by the lakes, a relaxing affair. A lake is a place of many ‘Hellos’ – familiar hellos and new hellos. Here, friendships are formed, much-needed alone time is sought, communities come together and outdoor recreation is pursued. With its long, downward-curved bill,
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