Limnological Studies on Somasila Reservoir in Nellore District, Andhra Pradesh, India
M. Kartik *
Department of Aquatic Environment Management, College of Fishery Science, Muthukur, Nellore District, Andhra Pradesh, India.
K. Madhavi
Department of Aquatic Environment Management, College of Fishery Science, Muthukur, Nellore District, Andhra Pradesh, India.
R. R. Anupama
Department of Aquatic Environment Management, College of Fishery Science, Muthukur, Nellore District, Andhra Pradesh, India.
N. Jesintha
Department of Fisheries Resource Management, College of Fishery Science, Muthukur, Nellore District, Andhra Pradesh, India.
P. Venkata Srinivasulu
Department of Aquatic Environment Management, College of Fishery Science, Muthukur, Nellore District, Andhra Pradesh, India.
K. Pujitha
Department of Aquatic Environment Management, College of Fishery Science, Muthukur, Nellore District, Andhra Pradesh, India.
P. Pooja
Department of Fisheries Resource Management, College of Fishery Science, Muthukur, Nellore District, Andhra Pradesh, India.
Anamdasu Yasaswi
Department of Aquatic Environment Management, KUFOS, Kerala, India.
*Author to whom correspondence should be addressed.
Abstract
This study examined temporal variation in physicochemical characteristics of surface water and sediment in Somasila Reservoir, SPSR Nellore district, Andhra Pradesh, between December 2024 and July 2025. Samples were obtained monthly from three stations and analysed using standard methods. The monitoring period covered the northeast monsoon, winter, hot-weather season and southwest monsoon. Water variables included temperature, pH, dissolved oxygen, carbon dioxide, chloride, salinity, electrical conductivity, total dissolved solids, alkalinity, hardness and selected nutrients. Sediment measurements comprised pH, electrical conductivity, organic carbon and available nitrogen and phosphorus. Across the study period, water temperature ranged from 26.70 to 34.10 °C, pH from 7.25 to 8.50 and dissolved oxygen from 4.53 to 9.53 mg/L. Electrical conductivity ranged from 234.67 to 421.33 µS/cm, while nitrate and phosphate concentrations ranged from 0.017 to 0.367 mg/L and 0.067 to 1.020 mg/L, respectively. Higher water temperature and conductivity occurred during hot weather, whereas increased nitrite, nitrate and phosphate concentrations were observed during monsoon months. Sediment pH ranged from 6.03 to 7.77 and organic carbon from 0.62% to 1.24%. Descriptive analysis, correlation analysis and analysis of variance were used to examine relationships and variation among the recorded parameters. The results document seasonal differences in measured water and sediment properties and provide a baseline for continued reservoir monitoring and fisheries-related management.
Keywords: Somasila reservoir, limnology, physico-chemical parameters, water quality, sediment quality, phytoplankton, fisheries potential, seasonal variation