HR: 1400h
AN: GS23A-01    [Abstracts]
TI: Geochemical characterization of anthropogenic effects in coastal lagoons at the Northern Pacific coast of Mexico
AU: * Ruiz-Fernández, A C
EM: caro@ola.icmyl.unam.mx
AF: Universidad Nacional Autónoma de México. Institute of Marine Sciences and Limnology. Mazatlan Academic Unit., Calz. J. Montes Camarena s/n, Mazatlan, Sin 82040, Mexico
AU: Mellado-Vazquez, P G
EM: pyg_29@hotmail.com
AF: Instituto Tecnológico del Mar de Mazatlan, Calle Corsario 1 No. 203 Col. Urias, Mazatlan, Sin 82070, Mexico
AU: Bojorquez-Sanchez, S
EM: camarere@hotmail.com
AF: Instituto Tecnológico del Mar de Mazatlan, Calle Corsario 1 No. 203 Col. Urias, Mazatlan, Sin 82070, Mexico
AU: Páez-Osuna, F
EM: paezos@ola.icmyl.unam.mx
AF: Universidad Nacional Autónoma de México. Institute of Marine Sciences and Limnology. Mazatlan Academic Unit., Calz. J. Montes Camarena s/n, Mazatlan, Sin 82040, Mexico
AB: Sinaloa is a coastal state located in the Gulf of California that is characterized by an economy mostly based on agroindustry, fisheries, aquaculture and tourism. It has been recognized that the coastal lagoons neighboring the most developed economic areas of Sinaloa state are showing signs of infilling and eutrophication that have been related with the dumping of untreated effluents from agriculture croplands, aquaculture facilities and human settlements. The environmental impact to the lagoons of Navachiste, Santa María, Ohuira, Ensenada del Pabellón, Chiricahueto, Ceuta y Estero de Urías has been evaluated through the assessment of time dependent changes in the 210Pb-derived sedimentation rates and the sediment concentrations of geochemical constituents such as organic matter, carbonates and nutrients (N and P). 210Pb geochronology has shown that accretion rates and nutrient fluxes in some lagoons have considerably increased due to the development of the agriculture activities in the region. For instance, in Ohuira lagoon, at the area adjacent to the culture fields of El Fuerte Valley, sediment accumulation has increased ~5 times with respect to the pre-anthropogenic conditions in less than 20 years (0.06 to 0.32 cm yr^-1), while C, N and P fluxes (mg cm^-2 yr^-1) increased almost 10, 10 and 13 fold, respectively (4.0-37 for OC, 0.6-6.0 for N and 0.1-7.0 for P).
DE: 0470 Nutrients and nutrient cycling (4845, 4850)
DE: 1051 Sedimentary geochemistry
DE: 1115 Radioisotope geochronology
SC: Geochemical Society [GS]
MN: 2007 Joint Assembly