RT journal article T1 Dissolved organic matter distribution in the water column and sediment pore water of a highly anthropized coastal lagoon (Mar Menor, Spain): characteristics, sources, and benthic fluxes A1 Amaral, Valentina A1 Santos-Echeandía, Juan A1 Ortega Díaz, Teodora A1 Álvarez-Salgado, Xosé Antón A1 Forja Pajares, Jesús A2 Química Física K1 DOM K1 Benthic flux K1 Carbon K1 FDOM K1 Coastal lagoons AB Coastal lagoons are among the most productive and biodiverse systems in the world, as well as important sentinels of climate change. The Mar Menor is one of largest coastal lagoons in the Mediterranean Sea providing a variety of ecosystem services and resources for the community. However, in the last decades, this lagoon, has suffered drastic changes and deterioration (e.g., eutrophication, anoxic events) induced by human activities (mainly urban and agricultural). Here, we studied the processes involving the dissolved organic matter (DOM) pool with the aim of improving our understanding of the functioning of the lagoon as well as helping to implement strategies to prevent the deterioration of these systems. We analyzed the dissolved organic carbon (DOC) concentration and the optical properties of DOM (absorbance and fluorescence) in the column water during summer and winter 2018 and during eighteen month covering from 2016 to 2018. We further analyzed the DOM distribution in the sediments pore water and estimated benthic fluxes. Overall, we found that the composition of DOM was mainly associated and/or enhanced by the anthropogenic activities occurring around the lagoon. Thus, this DOM enters the lagoon via urban and agricultural runoff and drainage systems and wastewater treatment plants, and it is also affected by microbial activity in the lagoon. We observed a strong seasonal variability related with precipitations and the break down of the system in 2016 (phytoplankton bloom) that lead to the dead of 80% of the macrophytes. The sediments of the lagoon acted as a source of DOM and the estimated benthic fluxes were relatively higher than those reported in other estuarine systems, probably due to the relatively elevate content of organic matter and the intense microbial activity. DOM distribution was mainly related with the specific conditions occurring during the sampling period and reflects the anthropogenic impact that this lagoon is suffering. PB Elsevier SN 0048-9697 YR 2023 FD 2023-07-01 LK http://hdl.handle.net/10498/34001 UL http://hdl.handle.net/10498/34001 LA eng NO Spanish Program for Science and TechnologyTRAGSA DS Repositorio Institucional de la Universidad de Cádiz RD 08-nov-2026