RT journal article
T1 Drivers of dissolved organic matter transport in the Guadalquivir estuary (SW, Spain)
A1 Sánchez Rodríguez, Jairo
A1 Amaral, V.
A1 Sirviente Alonso, Sara
A1 Sierra Padilla, Ana
A1 Bruno Mejías, Miguel
A1 Forja Pajares, Jesús
A1 Ortega Díaz, Teodora
A2 Física Aplicada
A2 Química Física
K1 Dissolved organic carbon
K1 DOM net transport
K1 Dissolved organic matter
K1 EEMs-PARAFAC
K1 Guadalquivir estuary
AB The Guadalquivir Estuary is the largest in the southwest Iberian Peninsula and is influenced by various anthropic activities, such as damming and rice farming, which regulate river flow and provide lateral inputs to the system. Despite its role as a major source of freshwater and dissolved organic matter (DOM) to the Gulf of Cadiz, there has been limited research on the seasonal distribution of DOM and dissolved organic carbon (DOC) export. This study chemically characterizes DOM using its optical properties along the salinity gradient and during tidal sampling cycles conducted from 2018 to 2022, improving the understanding of DOM dynamics in the estuary. Results show that the DOM in the estuary is predominantly allochthonous, with humic-like components accounting for 85.8 ± 5.8 % of fluorescent DOM (FDOM), while protein-like components, associated with autochthonous processes, account for only 14.2 ± 5.9 %. Mixing and biogeochemical reactivity are the main processes controlling DOM distribution, with mixing being the most significant. Lateral inputs from marshes and rice crops play an important role, particularly in the intermediate zone. Autochthonous DOM is more prominent during the dry season, especially in Summer. The estuary exports 5.8 g C m−2 yr−1 of DOC, along with substantial amounts of humic-like and protein-like FDOM, especially during extreme rainfall events that increase river flow, and therefore, discharge. DOC transport from the Guadalquivir Estuary is low if we consider the dimensions of its watershed area, highlighting the impact of damming on DOC transport.
PB Elsevier
SN 0304-4203
YR 2025
FD 2025-04
LK http://hdl.handle.net/10498/37933
UL http://hdl.handle.net/10498/37933
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 08-nov-2026