CONCLUSION

Maintaining the balance among different taxonomic groups is vital for any aquatic ecosystem integrity. This study highlights the research required in the field of aquatic sciences particularly for tropical regions and the use of bioindicators such as diatom and macroinvertebrate communities. The bioindicators used differentiated the sampling sites based on the pollution level and substantiates of their wide applicability to monitor the environmental perturbations associated with human activities.

The BI and FBI indices lack tolerance values for few families/species which inhabit in high organic pollution. The addition of indicator value of many such species would enhance the efficacy of macroinvertebrate indices to highlight the ecosystem conditions in Indian region. In this regard, diatom community provided interpretable indications of specific changes in water quality, while macroinvertebrate assemblages could reflect only certain chemical changes. The case study on the urban wetlands exhibited a wide range of local impacts such as high nutrient loads due to common purpose water use, sewage inflows and agricultural run offs. These indices together showed the impacts due to chemical variations such as BOD and COD. The modification is required in BI and TDI indices with integration of locally dominant species; specific to eco-region to monitor trophic status is an obligatory. The current results which include TDI indices support the use of diatom indices for the biomonitoring wetlands. However, spatial and temporal variations, along with effects of catchment variations and human impacts needs to be accounted and this would aid in compiling data describing present situation and developing eco-region specific indicators. These indicators would be useful in the ecosystem’s monitoring and also in restoration and management measures.