Abstract
Autonomous, uncrewed surface vessels (USVs) may offer a way to improve how scientists estimate fish populations over large areas, like the Great Lakes. In Lake Erie, prey fish are currently monitored each year using multiple crewed research vessels. While these ships provide reliable information, they are limited by cost, availability, and operating range.
In this study, we tested whether an USV, a Saildrone Explorer, could be integrated into the existing Lake Erie prey fish survey to increase spatial coverage without reducing data quality. We compared sonar‑based measurements of fish abundance from the Saildrone with measurements collected by four research vessels (three currently in use and one used previously). Data were collected along paired 2‑kilometer transects throughout the lake.
Although some differences were observed between individual sampling events, likely due to changing weather and wave conditions, the overall fish density estimates from the USV were similar to those from the crewed ships. We found that the uncrewed and crewed vessels responded differently to wind and waves, which affected data quality and highlights the need for careful planning when using autonomous platforms.
Overall, our results suggest that adding USVs to existing surveys could improve fish population estimates by expanding survey coverage, increasing efficiency, and allowing crewed vessels to focus on additional biological sampling.