Test of a screw-style fish lift for introducing migratory fish into a selective fish passage device

Barriers are an effective mechanism for managing invasive species like sea lamprey in the Lau-rentian Great Lakes, but are detrimental because they limit the migration of desirable, native species. Fish passage technologies that selectively pass desirable species while blocking unde-sirable species are needed. Optical sorting tools combined with newly developed computer learning algorithms could be used to identify invasive species from high resolution imagery and potentially isolate them from an assortment of Great Lakes fishes. Many existing barriers lack fishways and optical sorting may require fish to be dewatered for image capture. The Archimedes screw, a device originating from 234 BC, offers the potential to continuously lift fish and water over low-head barriers or into an optical sorting device. To test the efficacy of an Archimedes screw fish lift to capture and pass Great Lakes fishes, we built a field-scale prototype and installed it at the Cheboygan Dam, Michigan USA in 2021. The fish lift safely transported 704 fish (688 of which were suckers) in 11 days. Passage of suckers through the fish lift increased with water temperature and attraction flow. There were no observed injuries in transported fish or mortalities in a subset of suckers held post-transport.