Fish Passage Through Dams On The Upper Mississippi River

The St. Paul District, US Army Corps of Engineers and the US Geological Survey Upper Midwest Environmental Sciences Center examined the effects of locks and dams (Figure 1) on longitudinal fish movement in the Upper Mississippi River (UMR). The objective of this Long Term Resource Monitoring Program study was to estimate the opportunity for upriver passage through dams by adult migratory fishes. I identified UMR migratory fish species, estimated current velocities through gate openings on UMR dams, compiled information on migration behavior, and estimated the swimming for north performance of UMR migratory fishes. I used this information in combination with river discharge and dam operation records to estimate opportunity for upriver fish passage through the dams. Another objective was to examine the records of fish movements through UMR dams and to determine the head (difference between tailwater and pool water levels) when the fish passed through the dams. These results, reported in an earlier Project Status Report (PSR96 O4), summarized the findings of 126 UMR fish mark-recapture and telemetry studies.