Lake Sturgeon Reproductive Ecology in the Upper Mississippi River

Lake Sturgeon (Acipenser fulvescens) are a fish species which is now protected from harvest and considered rare in the upper Mississippi River. Habitat fragmentation and overexploitation has led to historical population declines. Despite recent management efforts which have been effective in assessing population increases through stocking programs, reproductive success in the upper Mississippi River has yet to be determined. Since egg or larvae confirmation has never been documented in this location, the three main objectives of this project will be the identification of Lake Sturgeon spawning aggregations, the confirmation of eggs or larvae near these aggregations, and the habitat characterization of these spawning locations. Gill nets and trotlines will be employed to capture adult Lake Sturgeon, which will be implanted with ultrasonic transmitters. The data gathered from these transmitters will then be used to track their spawning movement patterns. In the areas where spawning aggregations are found, attempts will be made to capture Lake Sturgeon eggs, embryos, and larvae by utilizing egg mats, D-frame nets, and the Mini-Missouri trawl. The information gained in this study will help make improvements to stocking programs, which will ultimately enhance natural reproduction of Lake Sturgeon in the upper Mississippi River.