DR RIMJIM DUTTA
Assistant Professor,Pandit Deendayal Upadhyaya Adarsha Mahavidyalaya, Assam, India
Title of presentation: Assessment Of Ecological Health Of Three Ephemeral Streams In A Tropical Climate; An Inexhaustible Source Of Biodiversity
Abstract: Ephemeral streams are those which flow only during or after the periods of precipitation.The present work aims to assess the ecological health of three ephemeral streams (Baghjan,Singijan and Ghagorjan) using plankton, macroinvertebrate and fish as bioindicator.These streams are located about 25 kilometers away from Northlakhimpur town of Lakhimpur district,Assam,India. Because of inadequate knowledge of their biological characteristics, these streams are often excluded from proper biomonitoring , but these are one of the rich source of biodiversity. A total of 17 numbers of Phytoplankton species, 10 numbers of Zooplankton species, 23 numbers of Macroinvertebrate species and 23 numbers of fish species have been recorded from the studied three streams. Species composition and quantitative characteristics of plankton, macroinvertebrate and fish have been assessed by four diversity indices(Shannon,Simpson,Margalef and McIntosh) and two evenness indices(Pielow and McIntosh).The value of these diversity and evenness indices clearly indicate the moderate pollution of the three studied streams. Family level biotic index value for macro invertebrate were also determined and revealed significant organic pollution in the three streams. Various physicochemical parameters such as D.O., FCO2, total acidity, total alkalinity, chloride, water temperature, pH, current velocity and conductivity also have been analysed. Since the streams are ephemeral, so they completely dependent on monsoon rain. Monsoon starts from June and from the end part of November the streams starts dry up. Therefore the analysis of physicochemical parameters and macro invertebrate assemblages were done only for six months (June, July, August, September, October and November) as well as two seasons (monsoon and post monsoon. Impacts of anthropogenic activities on these freshwater ecosystems have been discussed.
Key words: Ephemeral,Diversity index,physicochemical parameters
Biography: Assam, India since 9th August, 2017. Her field of research deals with freshwater ecology. She Dr.Rimjim Dutta have been working as Assistant Professor in the department of Zoology in the Pandit Deendayal Upadhyaya Adarsha Mahavidyalaya Adarsha Mahavidyalaya, Dalgaon, Darrang has been analysing critically the existence of different biota and their interrelationship with environment as bio monitoring agent since 2010 under research programme of Dibrugarh University and awarded PhD in the year 2017.