Conclusion

Restoration of wetlands in Bangalore has only resulted in changes of physical aspects than any major improvisation of water quality and related wetland biota. Water bodies at Jakkur, Rachenahalli and Kothanur showed the dominance of pollution tolerant species such as Nitzschia palea, Nitzschia microcephala and Cyclotella meneghiniana. Species dominance and composition comprising pollution tolerant diatom species highlight that although Ulsoor and Madiwala wetlands were restored a decade ago, they are still severely polluted. This highlights the need for regular post-restoration monitoring to implement appropriate mitigation measures and to prevent the contamination of restored habitats. The restoration involving removal of shoreline riparian vegetation and construction of concrete bunds have led to the loss of breeding and roosting habitats for waterfowls and dependent benthic organisms. This demands for a review of the current restoration techniques in India by taking into consideration the sedimentation rate, suspended sedimentation concentration, habitat availability and nutrient uptake by different groups of organisms. Diatom based paleo-limnology with species composition analyses would aid in comprehending the past water quality, rate of sediment deposition, water depth and pollution conditions. Thus, diatom based bio monitoring would aid in establishing a benchmark to evaluate the restoration program by the decision makers and environmental managers.