Paddlefish Frequency and Timing of Dam Passage in The Upper Mississippi River (Pools 14-19)

The construction of navigational dams in the Upper Mississippi River (UMR) has disrupted movement and changed available habitat of the highly migratory paddlefish. The gates at each dam are open for different periods of time, allowing varying streamflow and opportunities for passage throughout the river. Lock and Dams (LD) 14,15, and 19 are infrequently at open river conditions, making it difficult for fish passage. To better understand native fish passage in this poorly understood region, we acoustically tagged 121 paddlefish and tracked their movements manually and with stationary receivers in Pools 14-19. Our manual and stationary receivers detected 98% of our tagged paddlefish. Our results indicated that 35 of our tagged fish successfully crossed over at least one dam barrier, either upstream or downstream direction. Paddlefish have demonstrated the ability to cross difficult barriers at LDs 14, 15, and 19. Ten of our paddlefish have exhibited extensive movements into Pools 4-10, demonstrating a clear need for interjurisdictional and cross-agency management efforts. A clear understanding of paddlefish movement in the UMR will allow researchers to better understand how to mitigate negative impacts from dams and assist in protecting and conserving paddlefish populations in the Mississippi River basin.