Methods of quantifying a mass mortality event in freshwater wildlife within the river ecosystem.

This study introduces a comprehensive method for quantifying mass mortality events in freshwater wildlife, exemplified by the ecological disaster in the Odra River in 2022. Our approach integrates field observations, statistical analysis, and ecological assessment to measure the impact of such events on various aquatic species. Key steps include systematic counting of deceased organisms, assessing population declines, and evaluating the ecological repercussions of invasive species. Utilizing the R programming language, we developed a framework that is adaptable to similar ecological crises in different aquatic environments. This methodology facilitates a detailed understanding of the scale and implications of mass mortality events, thereby contributing to effective environmental management and conservation efforts. •The analysis and modeling methods of the disaster are presented in the R programming language.•Exclusively open-source software was used for the analysis.•The analysis includes detailed data on the disaster's impact on various species.