Bycatch by fishing gear is a major cause of biodiversity loss. While bycatch is relatively well studied in marine ecosystems, there is limited information available on the frequency and the importance of bycatch in freshwater habitats, and the breadth of wildlife taxa affected. To explore this question, we conducted research based on online resources, including four social media platforms. We recorded 200 cases of fishing gear interactions with animals (excluding fish) between 1984 and 2024 in Hungary, along with information on the affected species and the location of the event. A total of 226 individuals of 64 animal species were affected by bycatch. Birds were the most frequently affected (60.6%), followed by reptiles (27.9%), while other taxa accounted for a total of 11.5% of records. The majority (72.6%) of the 226 bycaught individuals belonged to taxa protected by Hungarian law. The overwhelming majority of cases (n = 192, 96.0%) involved only two types of fishing gear: lines and/or fishing hook. Lost fishing gear was responsible for the majority of entanglements (n = 111, 55.5%), but actively used fishing gear was responsible for a comparable number of cases (n = 86, 43%). Our study highlights that bycatch from lost or active fishing gear poses a potential conservation concern requiring systematic investigation in freshwater ecosystems. Many of the affected taxa include species of conservation concern, underscoring the ecological significance of these interactions. In summary, our study highlights the conservation implication of bycatch in freshwater ecosystems, and calls for evaluating the true magnitude of its impact, especially in areas of high conservation importance.
Löki et al. (2026) studied this question.