Carbon dioxide emissions from Indian monsoonal estuaries

Abstract

Estuaries are known to be strong source for atmospheric CO sub(2), however, little information is available from Indian estuaries. In order to quantify CO sub(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 sub(2) to the atmosphere from Indian estuaries were 4–5 times higher during wet than dry period. The pCO sub(2) ranged between approx 300 and 18492 matm which are within the range of world estuaries. The mean pCO sub(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 sub(2) fluxes from the Indian estuaries, together with dry period data available in the literature, amounts to 1.92 TgC which is more than 10 times less than that from the European estuaries. The low CO sub(2) fluxes from the Indian estuaries are attributed to low flushing rates and less human settlements along the banks of the Indian estuaries.