Assessing the bioinvasion of the golden mussel (Limnoperna fortunei) through different watersheds in South Brazil: a comparison between quali-quantitative microscopic and molecular techniques

• Published in: Biological invasions 2025, Vol.27 (1), p.16
• Main Authors: Ostrensky, Antonio, Leite, Raissa Vitória Vieira, da Silva Bertão, Ana Paula, Stica, Paula Valeska, Horodesky, Aline, Mädder Netto, Otto Samuel, Pie, Marcio Roberto, Pestana, Débora, Zanin, Thiago Luiz, Pont, Giorgi Dal
• Format: Article
• Language: English
• Subjects: Bioinvasion; Biomedical and Life Sciences; Complementarity; Density; Developmental Biology; Ecological monitoring; Ecology; Economic sectors; Effectiveness; Environmental conditions; Environmental DNA; Environmental monitoring; Freshwater & Marine Ecology; Hydraulic structures; Hydroelectric power; Hydroelectric power generation; Introduced species; Invasive species; Larvae; Life Sciences; Limnoperna fortunei; Mollusks; Nonnative species; Original Paper; Plant Sciences; Polymerase chain reaction; Population studies; Qualitative analysis; Quantitative analysis; Real time; Water analysis; Water sampling; Watersheds
• ISSN: 1387-3547; 1573-1464
• DOI: 10.1007/s10530-024-03479-z

The invasive mollusc Limnoperna fortunei , commonly known as the golden mussel, poses significant threats to ecosystems and economic sectors, primarily hydroelectric power generation, due to the encrustation of hydraulic structures, which leads to clogging and efficiency loss. Effective monitoring is essential for implementing management strategies against this species. This study compared two methodologies for monitoring L. fortunei : a conventional microscopic inspection, which involves visually identifying and counting the larvae of L. fortunei in water samples, and a molecular approach using environmental DNA (eDNA) via real-time PCR, which detects the presence of L. fortunei by amplifying and analysing its DNA in water samples. Both methods were used to qualitatively and quantitatively assess L. fortunei in ecological water samples across 16 watersheds in Paraná, southern Brazil, aiming to determine their efficacy and complementarity. The molecular approach demonstrated high sensitivity, with results ranging from 50.0 to 97.5% agreement with the conventional method, influenced by environmental and temporal factors. In qualitative comparisons, complete concordance between methods was observed in 72.5% of cases, with molecular tests yielding positive results in 15.5% of cases where conventional methods produced adverse outcomes. Quantitative analysis revealed a weak positive correlation between eDNA concentrations and larval densities (Spearman’s ρ = 0.1878, p = 0.2168), with no significant differences in the distributions of density categories between methods (Wilcoxon test, p = 0.3694) and weak agreement in quantitative analyses (Cohen’s Kappa κ = 0.1509). Each method presented unique strengths: the molecular approach, while highly sensitive, was prone to false negatives due to PCR inhibition, whereas the conventional method faced challenges in detecting low-density populations. The study concludes that combining both approaches provides a more robust monitoring strategy, enhancing detection accuracy across various environmental conditions, and recommends using both methodologies while considering ongoing methodological improvements for effective ecological monitoring of this invasive species.