Geochemical aspects of organic matter from surface sediments of two estuarine systems in the São Paulo State: Bertioga Channel and Cananéia-Iguape Estuary Bruno Otero Sutti, Vitor Gonsalez Chiozzini, Christian Millo, Elisabete de Santis Braga

Abstract

In subtropical estuaries, geochemical studies of sedimentary organic matter (SOM) have contributed to measures of adaptation to climate change. The objective of this study was to evaluate the SOM geochemistry of different sectors of the Bertioga Channel and the Cananéia-Iguape estuary through determinations of metals and isotopic compositions. A large and intense depositional area was evidenced in the central region of the Bertioga Channel, where SOM was associated with the highest concentrations of Fe and Zn. The SOM observed in the Bertioga Channel showed a high influence of dissolved organic carbon (DOC) of terrestrial origin, while the SOM observed in southern sectors of the Cananéia-Iguape estuary showed a high influence of the DOC of marine origin.