Upper Mississippi River longitudinal and lateral movements

Dams on large rivers have profoundly affected patterns of fish movement and have disrupted natural flow regimes. In the upper Mississippi River, a series of 29 lock and dam structures control water levels and flow to facilitate commercial barge traffic and control flooding. Dams vary in the degree to which they regulate flow, with some dams commonly entering open-river conditions while a few dams are infrequently in open-river condition. Understanding how native and invasive fishes move through the navigation locks and dams on the upper Mississippi River is critical to help managers conserve native species and control invasive species. A network of agencies collaborates to maintain a large-scale acoustic telemetry array that stretches throughout the upper Mississippi River and its tributaries.