Abstract: Urbanisation, industrialisation, population growth and various agricultural activities in and around coastal areas have led to a significant amount of pollutants into the surrounding aquatic ecosystem such as estuary, river, sea, seashore and coastal wetlands. This causes ecological degradation. Pollution is one of the major challenges to the sustainability of coastal areas. In the study area, major industries are located on the Gurupur river bank which joins the Nethravati river to form a common estuary before entering the Arabian sea. The major activities that are responsible for coastal pollution in the study area are discharge and disposal of untreated domestic and industrial wastes to estuaries, rivers, nearshore waters and harbour activities. Gurupura and Nethravthi are two west flowing rivers of the Mangaluru coastal region. They receive a large amount of pollution load from the nearby industries causing the deterioration of the water quality. In this study, 10 surface water samples which include stream water, river water and sea water, were collected during the pre-monsoon and post-monsoon and analysed for various water quality parameters by adopting standard methods. The study reveals that the electrical conductivity, total dissolved solids and chlorides concentration of most of the surface water samples were met above the standard limits in both seasons. From the correlation analysis, it was found that a very strong correlation was observed between chlorides and hardness (0.9691), TDS and conductivity (0.9227) during post-monsoon season of 2018 and TDS and conductivity (1.00), COD and chlorides (0.8922), DO and chlorides (0.8810) during pre-monsoon of 2019.
