Estimación de abundancia de ensambles de peces de agua dulce mediante métodos de pesca y ADN ambiental.
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Date
2024
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Universidad de Concepción
Abstract
Estudiar la diversidad y abundancia de las comunidades de peces nativos e introducidos es crucial para la gestión y conservación de los ecosistemas acuáticos, tanto para monitorear las poblaciones de especies nativas como para detectar la presencia de especies invasoras, comprender la estructura de las comunidades y cómo la presencia/ausencia de las especies pueden alterar las dinámicas de los ecosistemas. Recientemente, el ADN ambiental (eDNA) ha emergido como una herramienta eficaz para monitorear la biodiversidad sin necesidad de una captura directa del organismo. En algunos casos esta técnica ha demostrado ser más eficiente que los métodos tradicionales y ha generado gran interés en su integración en estrategias de conservación acuática. En esta investigación se estudió la diversidad y abundancia del ensamble de peces del estero Nonguén, uno de los tributarios más importantes del río Andalién, en cuatro estaciones combinando metabarcoding de eDNA, un ensayo de qPCR específico para trucha arcoíris, una especie introducida, y estimaciones de abundancia obtenidas mediante un modelo de depleción a través de pesca eléctrica. Los resultados mostraron que la pesca eléctrica capturó una mayor diversidad de especies que el metabarcoding de eDNA. El ensayo de qPCR específico para trucha arcoíris resultó ser más sensible en la detección de la especie en todos los sitios de muestreo en comparación con el metabarcoding de ADN ambiental. Sin embargo, los ensayos realizados con este último resultaron ser sensibles en la detección de especies que no fueron capturadas mediante pesca eléctrica; tales como G. australis y P. irwinii. Los resultados de la regresión lineal entre la abundancia relativa estimada por el método de depleción y los datos obtenidos mediante ADN ambiental no reveló una relación estadísticamente significativa. Finalmente, aunque cada método presenta sus propias limitaciones y sesgos, la combinación de ambos proporciona una visión más amplia de la dinámica y ecología de estas especies.
Studying the diversity and abundance of native and introduced fish communities is crucial for the management and conservation of aquatic ecosystems, both to monitor native species populations and to detect the presence of invasive species, understand community structure, and how the presence/absence of species can alter ecosystem dynamics. Recently, environmental DNA (eDNA) has emerged as an effective tool for monitoring biodiversity without the need for direct organism capture. In some cases, this technique has proven to be more efficient than traditional methods and has generated great interest in its integration into aquatic conservation strategies. In this research, the diversity and abundance of the fish assemblage in the Nonguén stream, one of the most important tributaries of the Andalién River, were studied at four stations, combining eDNA metabarcoding, a qPCR assay specific for rainbow trout, an introduced species, and abundance estimates obtained through a depletion model using electrofishing. The results showed that electrofishing captured a greater diversity of species than eDNA metabarcoding. The qPCR assay specific for rainbow trout was more sensitive in detecting the species at all sampling sites compared to environmental DNA metabarcoding. However, assays conducted with the latter were sensitive in detecting species that were not captured through electrofishing, such as G. australis and P. irwinii. The results of the linear regression between the relative abundance estimated by the depletion method and the data obtained through environmental DNA did not reveal a statistically significant relationship. Finally, although each method has its own limitations and biases, combining both provides a broader view of the dynamics and ecology of these species.
Studying the diversity and abundance of native and introduced fish communities is crucial for the management and conservation of aquatic ecosystems, both to monitor native species populations and to detect the presence of invasive species, understand community structure, and how the presence/absence of species can alter ecosystem dynamics. Recently, environmental DNA (eDNA) has emerged as an effective tool for monitoring biodiversity without the need for direct organism capture. In some cases, this technique has proven to be more efficient than traditional methods and has generated great interest in its integration into aquatic conservation strategies. In this research, the diversity and abundance of the fish assemblage in the Nonguén stream, one of the most important tributaries of the Andalién River, were studied at four stations, combining eDNA metabarcoding, a qPCR assay specific for rainbow trout, an introduced species, and abundance estimates obtained through a depletion model using electrofishing. The results showed that electrofishing captured a greater diversity of species than eDNA metabarcoding. The qPCR assay specific for rainbow trout was more sensitive in detecting the species at all sampling sites compared to environmental DNA metabarcoding. However, assays conducted with the latter were sensitive in detecting species that were not captured through electrofishing, such as G. australis and P. irwinii. The results of the linear regression between the relative abundance estimated by the depletion method and the data obtained through environmental DNA did not reveal a statistically significant relationship. Finally, although each method has its own limitations and biases, combining both provides a broader view of the dynamics and ecology of these species.
Description
Tesis presentada para optar al título de Bióloga
Keywords
Biodiversidad, Peces, Agua dulce