Paddlefish Dam Passage Efficiency and Habitat Use in the Upper Mississippi River (Pools 14-19)

The construction of navigational dams on the Upper Mississippi River (UMR) has disrupted movement and changed available habitat of the highly migratory paddlefish. Gate operation is variable resulting in fluctuating streamflow and fish passage opportunities. Lock and Dams (LD) 14,15, and 19 are infrequently at open river conditions, making fish passage difficult. To better understand native fish passage and habitat use in this understudied region, we acoustically tagged 121 paddlefish and tracked their movements with manual and stationary receivers in Pools 14-19. Our manual and stationary receivers detected 97% of our tagged paddlefish. Our results indicated that 18 of our tagged fish successfully crossed at least one dam barrier upstream or downstream. Paddlefish have demonstrated the ability to cross difficult barriers: 6 passages at LD 15 and 4 passages at LD 14. Most paddlefish detections were observed in backwater habitat in summer 2018 and have been observed to move towards channel borders in the late fall. A clear understanding of paddlefish movement and habitat use in the UMR will allow researchers and biologists to better understand dam passage of other migratory fish species.