Hydrological Characteristics in relation to Fish composition in Tammadihalli tank of Bhadravathi Taluk, Karnataka
H.M. Ashashree1 and B.R. Kiran2
1Department of Zoology, Sahyadri Science College, Shivamogga-577 203 (India) 2Department of Environmental Science, DDE, Kuvempu University, Shankaraghatta-577451 (India)
ABSTRACT
Assessment of physico-chemical and fish composition characteristics of water in two sampling sites in Tammadihalli tank of Bhadravathi taluk, Karnataka was analysed during March to November 2017. This water body is situated 26 Km away from Shivamogga district of Karnataka. The main aim of this study is to understand the hydrological characteristics of tank water and to search out out the suitability of water for drinking and fisheries . Several parameters like pH, water temperature, total alkalinity, total hardness, acidity, calcium, magnesium, electrical conductivity, phosphate, nitrate, dissolved oxygen, biochemical oxygen demand, total dissolved solids, turbidity, chloride and sulphate were analysed as per standard method and compared with WHO and BIS standards. The current study revealed that the water has pH (6.9 - 7.5), water temperature (23 - 34.5° C), electrical conductivity (101 - 138 μmhos / cm), total dissolved solids (50.5 - 79 mg/l), turbidity (89 - 222 NTU), acidity (5.01 – 7.2 mg/l), alkalinity (62.2 -73.5 mg/l), dissolved oxygen (2.84 – 6.8 mg/l), biochemical oxygen demand (2.2– .2 mg/l), total hardness (49.84- 59.5 mg/l), calcium (13.45 – 28.5 mg/l), magnesium (10.45 –17.25 mg/l), chloride (39.5 – 49.7 mg/l), sulphate (39.05 – 51.35 mg/l), phosphate (0.02 - 0.06 mg/l) and nitrate (0.03 - 0.08 mg/l). In this tank few indigenous and exotic fishes were recorded. Water quality in Tammadihalli tank is influenced by hydrology, topography and other environmental factors, which cause variations in nutrients. The physicochemical analysis of water samples from this tank showed that the water is within the safe limits of drinking, irrigation and fisheries. Hence, the current water body is included under moderately mesotrophic category.