Submarine groundwater discharge to the Bay of Bengal is studied using sea-bed porewater temperature as a tracer. By mapping temperature and chemical profiles, researchers identified seasonal groundwater discharge zones. They found that these zones are enriched with algal mats, indicating nutrient discharge that boosts marine ecosystem productivity. The estimated average annual groundwater discharge to the Bay of Bengal is about 1.16 × 107 m3/y, with higher rates during pre-monsoon and post-monsoon seasons. Monsoonal activity increases groundwater discharge, displacing porewater from tidal flat sediments.