Biomonitoring as a Strategy for Ecosystem Health ? A Case Study at the Upper Reaches of Vamanapuram River, Kerala

The present study was carried out using aquatic insects as bio monitors in the upper reaches of Vamanapuram river Kerala, The investigation was for a period of one year, from February 2014 to January 2015. The study adopted large river bioassessement protocol to assess the impact of anthropogenic pressure on aquatic insect population. Insect population showed significant spatial and temporal variations in reference site and test site. Twenty insect families under seven orders were recorded from the reference site and 13 insect families under five orders were observed at test site. Cluster analysis, Two way ANOVA and PCA was conducted by using the software, PAST 3.4. for Windows 7. Family biotic index of reference site ranged from 4.43 to 4.7 whereas in test site it was in the range of 5.94 to 6.63, indicating poor water quality in the latter. The significant increase of the tolerant taxa in the test site implies considerable ecological degradation in the study period.