A study conducted by the CSIR-Central Salt & Marine Chemicals Research Institute (CSIR-CSMCRI), Bhavnagar, has found that the marine ecosystem around Tata Chemicals Limited’s treated wastewater discharge point at Mithapur remains healthy, stable and productive. The assessment covered water and sediment quality, marine biology, vegetation and bird populations within a 10-kilometre radius of the discharge point in the Gulf of Kutch. The study was carried out as part of the biennial monitoring requirements linked to the approval of the treated wastewater discharge pipeline project.
Field studies were conducted in December 2025 and May 2026, with the report released in August 2026. According to the findings, water and sediment quality parameters remained within natural ranges, while local marine conditions continued to be influenced mainly by natural marine and tidal processes.
The study recorded 637 birds belonging to 40 species, including migratory birds using the Central Asian Flyway. The sampling location closest to the discharge point recorded the highest bird abundance, including around 250 Greater Flamingos. The report also found that the mudflats around Mithapur continue to support feeding activity for several bird species. Mangrove vegetation, mainly comprising Avicennia marina, was assessed as healthy and continues to provide habitat and help stabilise the shoreline.
Marine biological observations also indicated a productive ecosystem. The plankton community recorded 22 phytoplankton species and 23 zooplankton species, supporting the presence of a diverse marine food chain. Key seawater parameters, including pH, salinity, dissolved oxygen and biochemical oxygen demand, were found to be within ranges considered typical of a healthy coastal marine environment. Diversity indices for vegetation communities also showed no evidence of environmental degradation in the assessed area.
The assessment is the first report submitted under the ongoing monitoring framework for the treated wastewater discharge pipeline. The findings provide an independent assessment of the coastal environment following the transition to the treated wastewater pipeline system.
CSIR-CSMCRI is a national constituent laboratory of the Council of Scientific & Industrial Research under the Government of India. Based in Bhavnagar, Gujarat, the institute works in areas including marine ecology, salt technologies and environmental monitoring and is an accredited testing laboratory under the National Accreditation Board for Testing and Calibration Laboratories. The study covers environmental conditions around Tata Chemicals’ Mithapur operations and forms part of the company’s continuing environmental monitoring programme.
Tata Chemicals Limited, part of the Tata Group, supplies products to the glass, detergent, industrial and chemical sectors. The company also has a presence in crop protection through its subsidiary Rallis India Limited and operates research and development facilities in Pune and Bengaluru.
