- 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.