Carbon sequestration in the bottom sediments of aquaculture ponds of Orissa, India

Aquaculture ponds cover an area of 0.79 million hectare (Mha) in India, and have a large potential to bury carbon (C) in sediments with an attendant impact on off-setting related gaseous emissions. The study was aimed at assessing the potentials of C burial rates in the sediments of shrimp (Penaeus monodon), scampi (Macrobrachium rosenbergii) and polyculture (culture of Indian major carps, Catla Catla, Labeo rohita, Cirrhinus mrigala and Macrobrachium rosenbergii) ponds. The age of these ponds ranged from 12 to 15 years. The annual C sequestration rate estimated from sediment accumulation rate, dry bulk density, and percentage organic C in sediment of polyculture (Indian major carps plus scampi), shrimp and scampi culture ponds were 1463 ± 70 to 1530 ± 80, 863 ± 40 to 864 ± 56, and 1099 ± 75 kg/ha/yr, respectively. The estimated rates of C burial by C budget for all the studied species were almost similar to those determined by the sediment core analysis. Total technical potential of C sequestration in 0.79 Mha of aquaculture ponds in India ranges from 0.6 to 1.2 Tg C/yr with an average of 0.9 Tg C/yr which is 0.2% of Indian current, annual carbon emission.