Volume No. 11 Issue No.: 2 Page No.: 308-316 October-December 2016
COMPARATIVE STUDY ON MACROINVERTEBRATES POPULATION IN FOUR DIFFERENT TYPES OF WETLANDS OF LOWER SUBANSIRI BASIN, ASSAM, INDIA
Doley N.* and Kalita S.
Department of Environmental Science, Gauhati University, Guwahati (INDIA)
Received on : July 5, 2016
The wetlands of the Lower Subansiri Basin of Assam, India have been reported to be deteriorating due to ever increasing exploitation of resources available in the wetlands and human intervention in their natural functioning. Hence the wetlands were extensively studied with a holistic approach using benthic macroinvertebrates as bioindicators which gives a tangible distinct picture to monitor the health of aquatic ecosystem. Aquatic macroinvertebrate diversity in the wetlands of the Lower Subansiri Basin was monitored in four selected wetlands belonging to four different types of wetlands namely : Oxbow, Lake/Pond, Waterlogged and Riverine. The macroinvertebrates are very sensitive to changes in several abiotic parameters of the aquatic habitats and are also regarded as one of the indicators of the health of a wetland. The study was done for three seasons viz : Premonsoon, Monsoon and Postmonsoon in the year 2013. A total of 150-200 individuals were collected from each of the wetlands in both the seasons. 21 families of aquatic insects were observed in the wetlands, of which all the families that comes under order Hemiptera were found to be the dominant group. The population density of the aquatic insects was observed with similar distribution all throughout the season, however monsoon seems to have been integrated with most of the sensitive or pollution intolerant aquatic insects as compared to the other seasons. Most of the sensitive macroinevertebrates were observed in the waterlogged category indicating the wetland as healthier than the rest of the categories. Shannon Weiner Diversity Index of macroinvertebrates ranged from 1.99 to 2.45 showing a substantial diversity and distribution of macroinvertebrates in the wetlands.
Keywords : Lower Subansiri Basin, Wetlands, Macroinvertebrates population, Shannon Weiner Diversity Index and Evenness