Distribución vertical del contenido de Cu, Cd, Pb, y Zn en sedimentos submareales del Golfo de Arauco.
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Date
2024
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
El Golfo de Arauco es una extensión de agua situada en la región del Biobío, en el centro-sur de Chile. Limita al norte con la península de Hualpen y al sur con la Punta de Lavapie, en la costa de la provincia de Arauco. Este golfo es reconocido por su importancia ecológica y socioeconómica, albergando diversos ecosistemas marinos y siendo una zona que se caracteriza por estar influenciado por la actividad humana, debido a la gran actividad pesquera, industrial y turística de la zona (Hernández et al., 2024).
Estas actividades pueden generar la descarga de contaminantes en las aguas superficiales, que luego se depositan en los sedimentos del golfo. Esto puede resultar en la contaminación de los ecosistemas marinos y afectar la calidad del agua. Por ejemplo, los metales que pueden ser tóxicos en determinadas concentraciones para los seres vivos. Dentro de este grupo encontramos el Cd, Cu, Pb, Zn que al ingresar a los ambientes marinos pueden superar las concentraciones naturales y que son introducidas al mar tanto por procesos naturales como por la acción humana (Li et al., 2025)
El impacto de estas actividades se puede ver reflejado en los sedimentos marinos, los cuales actúan como depósitos de las sustancias descargadas en las aguas superficiales y que son introducidas al mar tanto por procesos naturales como por la acción humana.
Para abordar esta problemática se extrajo un testigo de sedimento del golfo de Arauco, en el punto 37°08.184' S, 73°17.920' W. El testigo obtenido tuvo una longitud de 72 centímetros y se determinaron las características fisicoquímicas del testigo de sedimento (Materia Orgánica Total (MOT), Densidad Aparente y Humedad), la concentración de los metales seleccionados (Pb, Cd, Cu y Zn) y además se realizó un archivo geocronológico para determinar la edad del testigo mediante la actividad del 210Pb, empleando el modelo de flujo constante (CRS) (Bermedo Cárdenas, 2025).
Los resultados de este testigo muestran que el sedimento está conformado por limos medios casi en su totalidad y un MOT promedio del 9,08%.
Los metales Cd, Cu y Zn presentan una distribución vertical altamente variable en su comportamiento a lo largo del testigo de sedimento. Por otra parte, el Pb tiene una concentración que desciende exponencialmente hasta el centímetro 10 del testigo, para x luego adoptar un comportamiento uniforme hasta la base.
Las concentraciones basales de los metales en la zona fueron: Pb 10,3 μg g-1, Cd 14,48 μg g-1, Cu 53,23 μg g-1 y Zn 88,95 μg g-1. De acuerdo con la geocronología, el corer presenta una edad estimada de 97 años.
Los resultados del índice de geoacumulacion (Igeo), reportó valores alrededor de 0 ó menores, por lo que quedaron catalogados como no contaminados. En cuanto al factor de enriquecimiento (FE), reportó valores < 2 para los 4 metales seleccionados, clasificándolos como enriquecimiento mínimo. Y para finalizar el índice de carga contaminante arrojó valores < 1, clasificándolo como ausencia de contaminantes.
The Gulf of Arauco is a body of water located in the Biobío Region, in south-central Chile. It is bordered to the north by the Hualpén Peninsula and to the south by Punta Lavapié, along the coast of the Arauco Province. This gulf is renowned for its ecological and socioeconomic importance, including diverse marine ecosystems and being an area characterized by human activity, mainly due to extensive fishing, industrial, and tourist activities (Hernández et al., 2024). The above mentiones can generate the discharge of contaminants into surface waters, which subsequently accumulate in the sediments of the gulf. This can result in the pollution of marine ecosystems and affect water quality. For example, metals can be toxic to living organisms at certain concentrations. Among this group we find Cd, Cu, Pb, and Zn, which, upon entering marine environments, can exceed natural background levels and are introduced into the sea through both natural processes and human activities (Li et al., 2025). The impact of these activities is reflected in marine sediments, which act as reservoirs for substances discharged into surface waters. These pollutants are introduced into the sea by both natural processes and human activity. To address this problem, a sediment core was extracted from the Arauco Gulf at coordinates 37°08.184' S, 73°17.920' W. The core obtained had a length of 72 centimeters and its physicochemical characteristics were determined. Additionally, the concentrations of selected metals (Pb, Cd, Cu, and Zn) were measured, and a geochronological analysis was conducted to determine the core age using the constant flux activity (CRS) model (Bermedo Cárdenas, 2025). The results of this core indicate that the sediment is composed mostly of medium silt throughout its length, with an average total organic matter content of 9.08%. The metals Cd, Cu, and Zn exhibit highly variable vertical distributions along the sediment core. On the other hand, Pb shows an exponential decrease in concentration up to 10 centimeter depth in the core, followed by a uniform behavior towards the base. The baseline concentrations of metals in the area were as follows: Pb 10.3 μg g-1, Cd 14.48 μg g-1, Cu 53.23 μg g-1, and Zn 88.95 μg g-1. According to geochronology, the core has an estimated age of 97 years. Geoaccumulation results (Igeo) reported values around 0 or negative, classifying them as uncontaminated. As for the Enrichment Factor (EF), values < 2 were reported for the 4 selected metals, indicating minimal enrichment. Lastly, the pollution load index yielded values < 1, classifying it as the absence of pollutants.
The Gulf of Arauco is a body of water located in the Biobío Region, in south-central Chile. It is bordered to the north by the Hualpén Peninsula and to the south by Punta Lavapié, along the coast of the Arauco Province. This gulf is renowned for its ecological and socioeconomic importance, including diverse marine ecosystems and being an area characterized by human activity, mainly due to extensive fishing, industrial, and tourist activities (Hernández et al., 2024). The above mentiones can generate the discharge of contaminants into surface waters, which subsequently accumulate in the sediments of the gulf. This can result in the pollution of marine ecosystems and affect water quality. For example, metals can be toxic to living organisms at certain concentrations. Among this group we find Cd, Cu, Pb, and Zn, which, upon entering marine environments, can exceed natural background levels and are introduced into the sea through both natural processes and human activities (Li et al., 2025). The impact of these activities is reflected in marine sediments, which act as reservoirs for substances discharged into surface waters. These pollutants are introduced into the sea by both natural processes and human activity. To address this problem, a sediment core was extracted from the Arauco Gulf at coordinates 37°08.184' S, 73°17.920' W. The core obtained had a length of 72 centimeters and its physicochemical characteristics were determined. Additionally, the concentrations of selected metals (Pb, Cd, Cu, and Zn) were measured, and a geochronological analysis was conducted to determine the core age using the constant flux activity (CRS) model (Bermedo Cárdenas, 2025). The results of this core indicate that the sediment is composed mostly of medium silt throughout its length, with an average total organic matter content of 9.08%. The metals Cd, Cu, and Zn exhibit highly variable vertical distributions along the sediment core. On the other hand, Pb shows an exponential decrease in concentration up to 10 centimeter depth in the core, followed by a uniform behavior towards the base. The baseline concentrations of metals in the area were as follows: Pb 10.3 μg g-1, Cd 14.48 μg g-1, Cu 53.23 μg g-1, and Zn 88.95 μg g-1. According to geochronology, the core has an estimated age of 97 years. Geoaccumulation results (Igeo) reported values around 0 or negative, classifying them as uncontaminated. As for the Enrichment Factor (EF), values < 2 were reported for the 4 selected metals, indicating minimal enrichment. Lastly, the pollution load index yielded values < 1, classifying it as the absence of pollutants.
Description
Tesis presentada para optar al título de Biólogo/a Marino/a.
Keywords
Golfos, Sedimentos marinos, Contaminación, Calidad del agua