Carbon dioxide emissions from Indian monsoonal estuaries

Estuaries are known to be strong source for atmospheric CO 2 , however, little information is available from Indian estuaries. In order to quantify CO 2 emissions from the Indian estuaries, samples were collected at 27 estuaries all along the Indian coast during discharge (wet) period. The emissions of CO 2 to the atmosphere from Indian estuaries were 4–5 times higher during wet than dry period. The pCO 2 ranged between ∼300 and 18492 μ atm which are within the range of world estuaries. The mean pCO 2 and particulate organic carbon (POC) showed positive relation with rate of discharge suggesting availability of high quantities of organic matter that led to enhanced microbial decomposition. The annual CO 2 fluxes from the Indian estuaries, together with dry period data available in the literature, amounts to 1.92 TgC which is >10 times less than that from the European estuaries. The low CO 2 fluxes from the Indian estuaries are attributed to low flushing rates and less human settlements along the banks of the Indian estuaries.