Tracing organic matter in a tropical estuary, Jaguaripe River, Brazil - Implications of its origin and distribution

Summary:

This thesis investigates the dynamics of organic matter (OM) in the Jaguaripe River estuary, focusing on suspended particulate organic matter (SPOM), sediment organic matter (SOM), and dissolved organic matter (DOM). Pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) was used as a novel method to identify OM sources revealing strong relationships between mangrove SOM and terrestrial plant-derived OM, with seasonal variations in coastal pelagic OM contributions influenced by riverine inputs and tidal movements. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) demonstrated that mangroves contribute significantly to DOM, with seasonal shifts in DOM composition driven by riverine and tidal forces. These findings highlight the complex interplay of water movements in shaping OM dynamics and the potential impact of human activities on these processes.