Water reservoirs are essential for regional economic development, as populations depend on them for agriculture irrigation, flood control, hydroelectric power generation, water supply for human consumption, and subsistence fishing activities. However, the reservoir environmental quality can be disturbed by enhanced sediment input and trace metal contamination, affecting human health as a consequence of contaminated water and fish consumption. With the purpose to understand the trends and extent of sediment accumulation and trace element contamination in the Oviachic reservoir (OV, northwestern Mexico) since its construction, the temporal variations of sediment accumulation, and As, Cr, Cu, Hg, Ni, Pb, and Zn concentrations, enrichment, and fluxes, were evaluated through the study of two 210Pb-dated sediment cores. We assumed that siltation and trace element contamination were driven by the development of anthropogenic activities in the region within the past ~ 70 years. Elemental concentrations accounted from null to minor enrichment for most elements, but moderate to significant enrichment by Hg. Mercury, As, and Cu fluxes have notably increased since the past decade, most likely because of a combination of anthropogenic and natural processes, including catchment erosion, artisanal gold mining, and recent drought conditions in the region. Arsenic and Hg concentrations may pose deleterious risks to biota in the reservoir, and consequently to humans through fish consumption, for which further biological and toxicological tests are advisable. This study highlights the importance of using sediment dating to assess historical trends of metal contamination and identify possible sources, to support decision-making in programs addressed to reduce environmental and health risks in aquatic ecosystems.
Bibliographical noteFunding Information:
This study was supported by the project grant # 20562 ?Accumulation and distribution of metals and metalloids in water, sediments and biota in the Yaqui River Basin, Sonora State,? from Centro de Investigaci?n en Alimentaci?n y Desarrollo, A.C. The scholarship of R. Ochoa-Contreras was provided by the Consejo Nacional de Ciencia y Tecnolog?a of M?xico. The authors are grateful to Adolfo Americano for the technical assistance during sampling activities and to Germ?n Ram?rez, Carlos Su?rez, and Le?n Felipe ?lvarez for the data curation and processing.
© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.
- Pb dating
- Climate variability
- Sediment accumulation rates
- Trace element contamination
- Water reservoirs