POLICY BRIEF: Significance of Systematic Estuarine Water Quality Monitoring in the Indian Sundarban

by Abhra Chanda, Sumana Banerjee, Souvik Shil and Tuhin Ghosh

The Indian Sundarban is a deltaic region characterised by coastal vegetation and mangrove forests and is highly dependent on the quality of its estuarine water. However, due to climate change and human activities, the water quality in this region is rapidly changing, affecting the ecosystem and the livelihoods of delta communities.

To address this issue, we have initiated a systematic monitoring program to establish baseline data for water quality. The program focuses on various parameters such as salinity, acidity/alkalinity, dissolved oxygen, nutrients, and phytoplankton biomass, which are crucial for understanding the ecological wellbeing of the estuaries.

Factors like salinisation, increased use of inorganic fertilizers, and the discharge of untreated sewage and industrial effluents are negatively affecting the water quality and ecosystem health.

Our findings reveal significant variability in salinity levels across different seasons and regions of the Sundarban. The central region of the Sundarban experiences high salinity during summer months, which can have far-reaching, severe impacts in the region. Mangroves, which are essential for the ecosystem, are stressed and their species composition is changing. Agricultural lands are damaged, leading to food security issues. Women whose livelihoods depend on collecting fish and prawns by walking through more than waist-deep water along the estuarine mudflats have reported an array of gynaecological diseases attributed to prolonged exposure to highly saline waters and skin diseases are also rampant. Furthermore, highly saline conditions corrode infrastructure and damage cultural heritage sites.

To address these challenges, we emphasise the significance of long-term and systematic monitoring of water quality to understand the changing ecosystem and develop effective policies. This monitoring should include relevant parameters and cover representative locations throughout the Sundarban. It is crucial for evidence-based environmental and socio-economic policies to manage the area effectively.

We have already established baseline data for water quality in the Sundarban., however, the continuation of the monitoring programme beyond the Living Deltas Project end (in 2024) is vital. Other measures, such as river rejuvenation, resilient embankments, and proper channelisation of freshwater are also needed to mitigate the impacts of estuarine salinisation.