“…small dams), could aid the conservation of a wide range of aquatic fauna, including eels (LaDeau et al, 2017). In Europe, collaboration amongst diverse environmental stakeholders and widespread use of crowdsourcing have put needed data in the hands of eel biologists (Belletti et al, 2020; Drouineau et al, 2021). The recent development of a machine learning algorithm that uses geospatial and lidar data to identify dams, even small ones, with reasonable accuracy (true positive rate 89%, false positive rate 1.2%) (Buchanan et al, 2022) may open the door to comprehensive inventories of dams of all sizes.…”