Spatial and temporal variations in physico-chemical characteristics of water in Gangavali and Aghanashini mangroves, Southwest coast, Karnataka

Abstract

Mangrove is a unique ecological environment and forms the habitat for a wide variety of marine organisms. The present study was carried out to investigate the water quality and nutrient dynamics in the selected mangroves of the Uttara Kannada district, Karnataka. The physico-chemical parameters of water were analyzed by standard methods. The study was conducted during the period from October 2021-September 2022. The physico-chemical properties showed significant seasonal variations at all the selected stations. The water quality parameters namely temperature, pH, salinity, alkalinity, hardness, DO, BOD, NH3-N, NO2-N, NO3-N, PO4-P, SiO3-Si were found to vary from 25 °C-34.5 °C, 7.1-8.5, 4-32 PSU, 40-162 mg/l, 468-11600 ppm, 4.48-8.96 mg/l, 0.4-6.11 mg/l, 0.63-23.68 µg-at./1, 0.06-3.28 µg-at./1, 0.13-10.55 µg-at./1, 0.11-20.5 µg-at./1 and 7.2-80.39 µg-at./1 respectively. The results showed that some parameters with slight deviations compared with optimal values. It was observed that the mangrove was provided with a diversified and rich fauna population and was shown to be significantly influenced by environmental variables. As a result, it is critical to monitor the health of the mangrove ecosystem in order to ensure more sustainable fisheries in the future.