Lock 19 underwater acoustic deterrent system study—Interim project update, through 2022

Invasive carp (Hypophthalmichthys nobilis [Richardson, 1845; Bighead Carp], H. molitrix [Valenciennes in Cuvier and Valenciennes, 1844; Silver Carp], Ctenopharyngodon idella [Valenciennes in Cuvier and Valenciennes, 1844; Grass Carp], and Mylopharyngodon piceus [Richardson, 1846; Black Carp]) expansion threatens the Laurentian Great Lakes and other major waterways. Numerous tools and techniques are being tested or developed to curtail the upstream expansion of invasive carps while minimizing the effect to native species. Underwater sound is one technology that has shown promise as a deterrent in the laboratory and ponds and is being considered for use at bottleneck locks and dams to reduce the risk of invasive carps moving to uninvaded areas. To test this technology at a management-relevant scale, an underwater acoustic deterrent system (UADS) was designed and installed at Lock 19 on the Mississippi River in 2021. The experimental UADS operates on a continuous schedule of 80 hours on and 80 hours off to allow for comparisons of fish behavior during varying environmental, operational, and navigation traffic conditions. Two telemetry systems, operating at 69 and 307 kilohertz, were deployed to evaluate how the UADS may affect movement and behavior of invasive carps and native fish species. During 2021–22, Silver Carp were twice as likely to pass over the UADS and into the lock when it was off compared to on; however, Bigmouth Buffalo, a native fish, were 1.2 times more likely to make upstream passage when the UADS was off compared to on.