The dynamics of fluorescent dissolved organic matter in the Paranaguá estuarine system, Southern Brazil

The aim of this study was to investigate the dynamics of the fluorescent dissolved organic matter (FDOM) in Paranagua Estuarine System (PES) as to infer about the contribution of allochthonous FDOM to the estuarine waters in relation to tidal condition and seasons. Fluorescence spectroscopy was used...

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Detalles Bibliográficos
Autores: Gusso-Choueri, Paloma Kachel, Choueri, Rodrigo Brasil [UNIFESP], Lombardi, Ana Teresa, Machado, Eunice da Costa
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:Brasil
Institución:Universidade Federal de São Paulo (UNIFESP)
Repositorio:Repositório Institucional da UNIFESP
Idioma:inglés
OAI Identifier:oai:repositorio.unifesp.br:11600/43138
Acceso en línea:https://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592011000400002
https://repositorio.unifesp.br/handle/11600/43138
Access Level:acceso abierto
Palabra clave:Humic substances
Estuaries
FDOM's source
Tidal cycle
Estuarine turbidity maximum
Fluorescence spectroscopy
Descripción
Sumario:The aim of this study was to investigate the dynamics of the fluorescent dissolved organic matter (FDOM) in Paranagua Estuarine System (PES) as to infer about the contribution of allochthonous FDOM to the estuarine waters in relation to tidal condition and seasons. Fluorescence spectroscopy was used for such purpose and DOM characterization through fluorescence emission was performed using excitation wavelengths of lambda ex 350 nm and lambda ex 450 nm, the two main fluorescence groups known to be present in natural DOM. Relations between emission wavelength (lambda em) and environmental variables, and the relevance of these variables to the different tides and seasons were identified by principal component analysis. The results showed that the first class of fluorophores (lambda ex 350 nm) changed from the river (freshwater) towards the estuary, whilst the second class (lambda ex 450 nm) has a more conservative nature and does not change as significantly as the first. Allochthonous DOM contribution to the estuarine system is intensified during the rainy season, especially in spring tides, whereas in the dry season the ratio of autochthonous DOM to total DOM in PES waters increased. We concluded that the variation of maximum lambda em of the first class of fluorophores (lambda ex 350 nm) is mainly related to allochthonous contribution, whilst the maximum of emission for the second class of fluorophores (lambda ex 450 nm) is dependent on the contribution of the different sources of organic matter (freshwater and marine water DOM contribution).