Assessment of physico-chemical parameters of New Mangrol Fishing Port, Gujarat

Abstract

Harbour environments are dynamic coastal systems that are highly prone to pollution due to intensive fishing operations, increased vessel movement and land-derived human activities. Therefore, systematic monitoring of harbour water quality is crucial for evaluating the effects of anthropogenic pressures. Accordingly, the present study evaluated the physico-chemical parameters of harbour water at Mangrol Harbour (New Mangrol Fishing Port), Gujarat, over an eight-month period from August 2024 to March 2025 across four sampling stations (Stations 1 to 4). Sixteen physico-chemical were analyzed to assess water quality. Water temperature ranged from 24.68 ± 0.064 °C to 30.37±0.034 °C, salinity from 30.44±0.017 ppt to 36.41±0.062 ppt, and pH remained moderately alkaline, varying between 7.65±0.034 to 8.36±0.026. Conductivity values ranged from 43.17±0.077 mS/cm to 50.70±0.069 mS/cm, while turbidity varied between 34.82±0.090 NTU to 38.46±0.144 NTU. Dissolved oxygen concentrations ranged from 3.60±0.036 mg/L to 3.99±0.039 mg/L, with biochemical oxygen demand values between 0.36±0.029 mg/L to 0.78±0.034 mg/L. Chloride content ranged from 16853.95±8.570 mg/L to 20199.16±35.091 mg/L, total hardness from 2470.19±12.431 mg/L to 2969.68±12.933 mg/L, and alkalinity from 122.42±2.648 mg/L to 166.79±1.882 mg/L. Total suspended solids ranged from 73.26±0.355 mg/L to 80.47±0.442 mg/L, total dissolved solids from 39.59±0.044 g/L to 44.22±0.261 g/L, and total solids from 39.67±0.044 g/L to 44.29±0.0265 g/L. Nutrient concentrations showed nitrate levels between 0.528±0.093 mg/L to 1.234±0.096 mg/L, phosphate from 0.067±0.003 mg/L to 0.196±0.003 mg/L, and ammonia from 0.240±0.015 mg/L to 0.437±0.020 mg/L. Seasonal variations indicated higher values of temperature, salinity, conductivity, dissolved solids, chloride, hardness and alkalinity during March, while turbidity, nutrients, suspended solids and microbial loads peaked in September. Overall, the water quality at New Mangrol Fishing Port remained within acceptable limits, though seasonal fluctuations reflect the influence of harbour activities and environmental conditions.