International audienceMangroves are extremely sensitive to the global climate change and urbanization impacts. To understand the effect of the urbanization on the organic matter of the coastal zone of Ceará State in north eastern Brazil, a seasonal filed campaigns were carried on in two most environmentally significant river/mangrove systems in the region; the Cocó river, in the metropolitan region of the huge city of Fortaleza, and the Pacoti River, an environmental protection area, without urban influence, on the east coast of the state. A spatial study was also done along the Jaguaribe river, which is the largest river in the state also connected to the largest mangrove area. Organic matter characterization by dissolved organic carbon, spectrofluorescence and fluorescence quenching and metal complexation capacity shows clearly that under urban pressure, the produced organic matter in mangrove area is different, meaning that carbon budget and pollutant fate have to be revised to take in account this difference
