Carbon dioxide emissions from Indian monsoonal estuaries

• Published in: Geophysical research letters Vol. 39; no. 3
• Main Authors: Sarma, V. V. S. S., Viswanadham, R., Rao, G. D., Prasad, V. R., Kumar, B. S. K., Naidu, S. A., Kumar, N. A., Rao, D. B., Sridevi, T., Krishna, M. S., Reddy, N. P. C., Sadhuram, Y., Murty, T. V. R.
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01-02-2012; American Geophysical Union; John Wiley & Sons, Inc
• Subjects: Biogeochemistry; Carbon; Carbon dioxide emissions; CO2 flux; Earth sciences; Earth, ocean, space; Estuaries; Exact sciences and technology; Geobiology; Human settlements; Organic matter; Particulate organic carbon; Asia; Europe; India; atmosphere; carbon dioxide; Wet spell; discharge; organic materials; decomposition; estuaries; Dry spell; organic carbon; greenhouse gas; settlement
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2011GL050709

Estuaries are known to be strong source for atmospheric CO2, however, little information is available from Indian estuaries. In order to quantify CO2 emissions from the Indian estuaries, samples were collected at 27 estuaries all along the Indian coast during discharge (wet) period. The emissions of CO2 to the atmosphere from Indian estuaries were 4–5 times higher during wet than dry period. The pCO2 ranged between ∼300 and 18492 μatm which are within the range of world estuaries. The mean pCO2 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 CO2 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 CO2 fluxes from the Indian estuaries are attributed to low flushing rates and less human settlements along the banks of the Indian estuaries.
Key Points
Indian estuaries emits ~2TgC annually to atmosphere
An order of magnitude high fluxes during discharge period
Intensive microbial decomposition of organic matter is the major source