Dissolved carbon dioxide and methane In estuaries and waters surrounding Mangroves on the east coast of india And the andaman islands

Abstract

This study reconsiders our current understanding of CO2 and CH4 newlineemissions from coastal margins especially from estuaries and mangroves newlinesurrounding waters Though coastal areas occupy lesser surface area when newlinecompared to the oceans their contribution to greenhouse gas emissions are newlinesignificantly higher Due to the intense biogeochemical transformations that newlinetake place in coastal zones these regions play an important role in the cycling newlineof carbon and emissions of important greenhouse gases Most of our newlineunderstanding of coastal biogeochemical processes is from studies in newlinetemperate areas and very few targeted studies have been carried out to date in newlinetropical zones The higher temperature in the tropics would suggest newlinesignificant atmospheric fluxes from the tropical coastal ecosystems CO2 and newlineCH4 concentrations and fluxes in three different mangrove Andaman newlineSundarbans and Pichavaram ecosystems and two different estuarine newline Hooghly and Adyar zones on the east coast of India and the Andaman newlineIslands were estimated The study sites were chosen based on the different newlineenvironmental settings and degree of anthropogenic impact newlineAll the sites showed high pCO2 and dissolved CH4 concentrations newlineand were a source of these gases to the atmosphere The heavily impacted newlineAdyar River showed the highest CO2 and CH4 fluxes followed the pristine newlineAndaman mangroves There appear to be no direct impact of anthropogenic newlineactivity on the emissions of these gases The concentrations distribution and newlinesubsequent emissions depend on rates of organic matter supply and burial newlinetidal pumping of porewaters redox status of sediment and overlying water newlinedilution with coastal waters and in the case of CH4 levels of sulphates newline