Monitoring of Water Pollution of Selected Freshwater Sites of Kollam District, using the Aquatic Insects as Bio Indicators

Aquatic ecosystems perform many important environmental functions like recycle nutrients, purify water, attenuate floods, recharge ground water and provide habitats for life. A stress on an aquatic ecosystem can be a result of physical, chemical or biological alterations of the environment. Aquatic insects of inland wetlands comprised some well known groups like mayflies, dragonflies, and caddis flies. Aquatic bio monitoring can represent the overall health and status of the environment; detect different environmental trends and how different environmental trends and how different stressors will affect of different environmental activity will have on the overall health of the environment. In the present study three diverse sites from Kollam district, Kerala were selected. They were Canal near Kattil mekkathil temple (site I), post retting site near kadavoor (sie II) and Ashatamudi, Link Road (site III). The main physical parameters were estimation of Carbon dioxide and Oxygen. Heavy metals under study were zinc, lead, iron, copper and nickel. Beyond these insect species were also collected. In an over view heavy metal was higher in the site-3. The dissolved oxygen concentration was lower in site-3 and carbon dioxide concentration was found higher. Main insects were collected from the three sites include Dobsonfly larvae, Water striders skate, Mayfly larva, Stonefly larva and Snipe fly larvae, Midge, True fly larvae, Drone flies, Red taild maggots, Snails and Left handed snail, Aquatic worm, Leech. Small red damselfly, Ceriagrion tenellum, Water striders skate, Freshwater mussels, Cranefly. As a conclusion, it is noted that the site I is slightly or less polluted, site II is moderated polluted and site III is highly polluted. Site III needed urgent strategies for pollution control.