Geographic Information System-Based Analysis of Fish Diversity Trends of River Meenachil, Southern Western Ghats, Kerala.

In this study, the fish fauna of different geographical zones Meenachil River was investigated using spatial interpolation techniques Geographical Information System. The variations in diversity trends during pre-monsoon, monsoon, and post-monsoon seasons from 2016 to 2020 along longitudinal gradient were determined Kriging method semivariograms. Sixty-seven species belonging 15 orders, 29 families, 46 genera recorded river study period. Twenty-five endemic Western Ghats, three exclusive Kerala, five nearly threatened, vulnerable. midstream maximum indices ranging (H’) 2.608 3.171, reflecting outcome local conservation efforts, downstream station with lowest range 2.305 -2.643. Cluster analysis showed similarities diversities between sampling stations. Deterioration water quality reflected fluctuating levels TDS (ppm) (21.300±116.828 365.000±116.828), Conductivity(µSmcm-1) (42.500±252.372 815.000±252.372), Salinity(ppt) (0.100±0.083 0.400±0.083) dissolved oxygen levels(mgL-1) (2.900±0.876 5.600±0.876). highlights necessity broaden efforts implement legal measures protect habitats native tourism-dominated lower stretches River. By integrating data maps, geographic component added by GIS gives a clearer insight into various efficiently supports global measures, enhancing biodiversity protection.