Biological invasions pose a significant threat to ecosystems and socio-economic interests globally. Despite advancements in invasion science, most studies focus on species-level approaches, often neglecting population-level processes that govern successful invasions. This study analyzes non-native species dynamics at the population level using a database of European freshwater macroinvertebrate time series to investigate spreading speed, abundance dynamics, and impact assessments. The findings reveal substantial variability in spreading speed and abundance trends within and between macroinvertebrate species across biogeographic regions, indicating that invasiveness and impact are context-dependent at the population level. The authors argue that invasion science should shift from species-level to population-level analyses, aligning with natural selection theory and emphasizing the importance of understanding regional population trajectories to assess ecological risk. The study highlights the need for more nuanced and context-specific approaches to invasive species management, as traditional species-level assessments often overlook the dynamic nature of differing populations within ecosystems.Biological invasions pose a significant threat to ecosystems and socio-economic interests globally. Despite advancements in invasion science, most studies focus on species-level approaches, often neglecting population-level processes that govern successful invasions. This study analyzes non-native species dynamics at the population level using a database of European freshwater macroinvertebrate time series to investigate spreading speed, abundance dynamics, and impact assessments. The findings reveal substantial variability in spreading speed and abundance trends within and between macroinvertebrate species across biogeographic regions, indicating that invasiveness and impact are context-dependent at the population level. The authors argue that invasion science should shift from species-level to population-level analyses, aligning with natural selection theory and emphasizing the importance of understanding regional population trajectories to assess ecological risk. The study highlights the need for more nuanced and context-specific approaches to invasive species management, as traditional species-level assessments often overlook the dynamic nature of differing populations within ecosystems.