Consumer-grade sonar applications for silver carp in overwintering habitats of the Lower Mississippi River, 2023 January 31

In January 2023, the USGS demonstrated the use of side-scan sonar and down-imaging sonar to locate and quantify fish including invasive carp. A dike pool in the study area was surveyed (254-meter reach) using a Humminbird Helix sonar system. Sonar surveys included concurrent recordings of side-scan and down-imaging sonar. Proprietary sonar data were converted to PNG image files (i.e., rectified and speed-corrected) using SonarTRX Pro. Fish targets in imagery were measured in total length and enumerated using image analysis software (ImageJ) algorithms. Side-scan and down-imaging datasets were processed multiple times across a range of sensitivity thresholds (i.e., 25–30) to incorporate variation in the sensitivity of fish detection and estimation. The resulting data set includes three CSV files documenting the track locations and beam information needed to calculate the ensonified volume and the fish counts and length of each fish captured in each sonar type.