Noriega C. auteur aut IRD Araujo M. auteur aut IRD Lefèvre Nathalie auteur aut IRD Montes M. F. auteur aut IRD Gaspar F. auteur aut IRD Veleda D. auteur aut IRD text journalArticle eng text/pdf born digital access Quantifications of CO2 fluxes across the air-water interface of estuarine ecosystems are needed to understand regional carbon balances. In this study, we estimate the amount of carbon emitted from tropical estuaries of the State of Pernambuco, Brazil, using measurements of temperature, alkalinity, salinity and pH at stations located in the estuaries. The results showed that the average CO2 fluxes (+51 +/- A 32 mmol m(-2) day(-1)) were mainly a product of the input of aloctone organic matter from urban centers with high population densities (similar to 1,000 inhabitants.km(-2)) adjacent to the estuarine systems. This organic material increased the amount of aqueous CO2, which increased the pCO(2) to 8,900 mu atm. October, November and December had the highest monthly averages of the parameters associated with the carbonate system (HCO3 (-), dissolved inorganic carbon, aqueous carbon dioxide, CO3 (2-), total alkalinity, temperature and pH), whereas the averages in July correlated with the CO2 fluxes. Multivariate analysis revealed that estuarine areas near the most densely populated areas (Beberibe-9,000 inhabitants.km(-2) and Paratibe-3,000 inhabitants.km(-2)) were positively correlated with high CO2 fluxes and high pCO(2). specialized CO2 fluxes Population density Tropical estuaries Brazilian coast BRESIL 032 062 15 4 619-630 2015 1436-3798 https://www.documentation.ird.fr/hor/fdi:010064067 10.1007/s10113-014-0671-3 1436-3798 [F B010064067] https://www.documentation.ird.fr/hor/fdi:010064067 https://www.documentation.ird.fr/intranet/publi/2015/04/010064067.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2015-05-04 2017-08-23 fdi:010064067 fre