Dissolved inorganic carbon (DIC) and its δ13C in the Ganga (Hooghly) River estuary, India: Evidence of DIC generation via organic carbon degradation and carbonate dissolution

The estimated annual DIC flux from the estuary to the Bay of Bengal is ca. (3-4) × 1012 g, of which ca. 40-50% is generated within the estuary. The monsoon periods account for the majority (ca. 70%) of the annual DIC generation in the estuary. The annual DIC flux from the Hooghly estuary accounts for ca. 1% of the global river DIC flux to the oceans. This is disproportionately higher than the water contribution from the Hooghly River to the oceans, which accounts for ca. 0.2% of the global river water flux. The results of this study suggest that estuaries in regions affected by tropical monsoon can be important in terms of their production of significant amounts of DIC and its delivery to the world's oceans.