Capture and storage of Carbon in seagrass beds of a vulnerable species Halophila beccarii (Asch.) at the Kadalundi Estuary, Kerala, India

Seagrass habitats are efficient carbon sink that can bury and store organic carbon for a long time. We report here the capture of dissolved CO2 by the ocean-turf grass, Halophila beccarii and its storage as carbon stock in the sediments extending an area of two hectares in the mudflats of Kadalundi Estuary. The organic carbon content in the seagrass sediment showed gradual increase from 0.473% during January to 0.824% during March. Organic carbon content in the sediment within the Halophila bed was 110134% higher than that of outside the seagrass bed. The three months observation, though a short term study revealed that the mean values of blue carbon stock of Halophila beds of Kadalundi Estaury were at 2.655±0.34 Mg C/ha. The capture potential of dissolved CO2 by the seagrass, unravelled through an experiment involving intact plants showed that the Halophila plants could utilize 21.4%– 25.7% of dissolved CO2 in light within 2 hours.