STUDIES ON SOME PHYSICO-CHEMICAL PARAMETERS OF WATER BODIES AND MICROBIAL FISH DISEASES IN EASTERN NEPAL

Abstract

The present study entitled “Studies on some physico-chemical parameters of water bodies and microbial fish diseases in Eastern Nepal” consisting of the experiment has been presented in three broad sections. First section deals with physico-chemical parameters of water bodies for two years (November 2008-October 2010) emphasizing with disease prone area. Second section deals with isolation, characterization and identification of bacteria and third section includes histopathology of naturally EUS infected fishes, other commonly occurred microbial fish diseases and pathogenicity of isolated bacteria and fungus from EUS affected fishes. Different physico-chemical factors of water of six water bodies; four ponds [three artificial ponds Baidya Fish Farm, Tankisinwari, Morang (S1), Babiya Birta Fish Farm, Morang (S2) and Tarahara Fish Farm,Sunsari (S3) and one natural pond, Betana Wetland, Morang (S4)] and two rivers Singhia river, Morang (S5) and Budhi river, Duhabi, Sunsari (S6) of eastern Nepal were studied for two years. Temperature, pH, turbidity, DO, BOD, free CO2, Chloride (Cl-), TA and TH were determined following standard methods. Correlation, t-test, two ways ANOVA among sites and seasons, and standard deviation were calculated using SPSS-V20 and Microsoft excel statistical function of computer software respectively. Out of six water bodies EUS outbreaks were recorded in three fish farms S1, S2 and S3 from 2008-2015. Generally the outbreak of EUS takes place in the month of December and persists up to March. No outbreak of the disease was found in three water bodies S4, S5 and S6. Results showed that prior to the outbreak of the disease there were significant (p<0.01, p<0.05) declining trends of two factors e.g. total alkalinity and total hardness of water of the three fish farms and the factors remained low for few months. Declining trends of total alkalinity and total hardness were also noticed in other water bodies where no outbreak of disease was found.