Quality assessment of pollution indicators in marine water at critical locations of the Gulf of Mannar Biosphere Reserve, Tuticorin

Highlights: • Anthropogenic activities lead to a vulnerable condition at the Tuticorin coast. • TSS and DO fluctuation affect marine biodiversity. • Microbial indicators highly exceed the seawater standard permissible limits. • Water quality monitoring is essential for the Gulf of Mannar Biosphere Reserve. • Baseline data for future monitoring, with respect of pollution of coastal ecosystems. - Abstract: The present study focused on the shoreline environment of urban and industrial areas, and the aim of this study was to assess the coastal water quality in the Gulf of Mannar Biosphere Reserve. Water samples were collected from five different coastal sites during the premonsoon and monsoon seasons. The samples were analyzed following the standard methods. The results showed that the levels of microbiological indicators in the samples highly exceeded the regional and national standard seawater permissible limits, and environmental parameters such as the total suspended solid and dissolved oxygen were affected significantly (p < 0.05). To identify frequent pollution indicators, their levels should be estimated to determine possible pollution in coastal ecosystems due to human interventions.