Ecological and socio-economic assessment of Varthur wetland, Bengaluru (India).

Wetlands are the most productive ecosystems, recognized globally for their vital role in sustaining a wide array of biodiversity and provide goods and services. But presently increased anthropogenic activities such as intense agriculture practices, indiscriminate disposal of industrial effluents and sewage wastes have altered the physical, chemical as well as biological processes of wetlands, which is evident from the present study carried out to assessVarthur wetland in India. Coastal wetland ecosystem in the world has 14,785/ha US$ annual economic value. An earlier study of relatively pristine wetland in Bengaluru revealed the value of ? 10,435/ha/day while the polluted wetland showed the value of ? 20/ha/day. On the contrary Varthur, a sewage fed wetland has a value of ? 118.9/ha/day. The pollutants and subsequent contamination of the wetland-Varthur has telling effects such as disappearance of native species, dominance of invasive exotic species (such as African catfish), in addition to profuse breeding of disease vectors and pathogens. Water quality analysis revealed high phosphate (4.22-5.76 ppm) level in addition to the enhanced BOD (119-140 ppm) and decreased DO (0-1.06 ppm). The amplified decline of ecosystem goods and services with degradation of water quality necessitates the implementation of sustainable management strategies to recover the lost wetland benefits of Varthur.