Freshwater fish monitoring in a subtropical reservoir: Integrating eDNA metabarcoding and traditional methods in biodiversity resolution, invasive species detection, and environmental correlates
Journal
Environmental and Sustainability Indicators
Journal Volume
27
Start Page
100831
ISSN
2665-9727
Date Issued
2025-09
Author(s)
Abstract
Subtropical drinking water reservoirs are ecologically sensitive systems facing environmental change and biological invasions. Effective biodiversity monitoring is essential for ensuring long-term water quality and ecosystem resilience. However, capture-based surveys often underrepresent cryptic or rare species. Environmental DNA (eDNA) metabarcoding offers higher sensitivity and demonstrated promising reliability, though its use requires contextual consideration. In this study, we applied eDNA metabarcoding for the first time in Feitsui Reservoir, a protected drinking water source in northern Taiwan, to assess fish community. We also integrated findings from traditional surveys to evaluate the reliability and complementarity of both approaches. eDNA detected 36 fish species, including all 23 recorded by conventional methods and five newly documented taxa. Among them, three species were exclusively identified via eDNA, highlighting its superior sensitivity. Multivariate analyses (NMDS, PCA, RDA) revealed method-specific community structures, with eDNA favoring native and small-bodied species, while traditional methods were biased toward large-bodied, invasive taxa. Environmental associations showed that dissolved oxygen and electrical conductivity correlated with eDNA-detected native species, while elevated water temperature was linked to invasive species. Importantly, eDNA detected native species presumed extirpated, suggesting potential shifts in ecosystem equilibrium. Our findings validate eDNA metabarcoding as a reliable and complementary approach for reservoir biodiversity monitoring. The results offer practical insights for long-term ecological assessment, invasive species management, and adaptive governance of subtropical reservoir ecosystems. We recommend integrating eDNA into monitoring and early-warning systems for invasive species in reservoir. Moreover, eDNA-derived biodiversity data can enhance ecological risk assessment by linking species distributions with environmental drivers.
Subjects
Ecological monitoring
eDNA metabarcoding
Freshwater biodiversity
Invasive species
Water reservoir
Publisher
Elsevier BV
Type
journal article