These results offer insight such as (1) all the three water quality regimes shows changes in water quality across seasons, (2) diatom species assemblages changes strongly in all the water quality regimes, due to seasonal water quality conditions, where physical forces are more significant over longer scales of study while eutrophication and regional landuse is moreover evident within climatic seasons, and (3) the species distribution across the sites followed the satellite-mode due to the specific ecological niches of the diatoms. This study also concludes that Western Ghats streams can be monitored during the post monsoon months for biomonitoring ventures and compared to other water monitoring programs. This study also hints that the diatom community in this region is rich with possible endemic taxa; hence considerable amount of importance has to be given for the taxonomy of the lesser-known species before starting the biomonitoring programs.

The analyses and results described here provide insights to the linkages between land use practices and water quality in the streams of CWG and the relative sensitivity of water quality variables to alterations in land use. Agricultural activities in stream catchments are closely linked to increasing nutrient and ionic concentrations. Water quality in the eastern leeward regions was most strongly influenced by agriculture land uses, whereas the western windward catchments were dominated by natural forests. The diatom indices and water chemistry variables relation clearly shows the impact of land use on stream ecosystem. Comparison of community structure for diatoms taken from sites with varying land uses using NMDS analysis reflected differences attributing to LULC. In conclusion, this study highlights the role of landscape and proximate factors in the regulation of diatom species assemblages. Understanding the relative importance of natural and anthropogenic variations on diatom species composition is essential for conservation of lesser known organisms like diatoms
It has been evident that the causes and sources of water pollution in the 5 River Basins are due to agricultural land use, anthropogenic activities and industrialization. The major occupation in the study area is agriculture, which is main source of increase in nitrates and ionic components in streams. Domestic and industrial sewage discharges in to rivers are responsible for the observed high concentration of electrical conductivity, total dissolved solids, total hardness and other ionic components. Proper treatment of effluent from the industrial processes to the acceptable levels and discouraging stagnation of water through small dams are the two major recommendations to minimize the river ecosystem damage in the central Western Ghats. Table 9 lists the threats and remedial measures.

Table 9: Threats and Mitigation Measures