Abstract
This study inferred that the majority of shovelnose sturgeon Scaphirhynchus platorynchus captured in the upper Mississippi River probably originated from locations outside the upper Mississippi River (Missouri River, middle Mississippi River); whereas, lake sturgeon Acipenser fulvescens exhibit infrequent movement outside of the upper Mississippi River, but may move throughout these interconnected large rivers at various life stages. By using pectoral fin‐ray microchemistry (a non‐lethal alternative to using otoliths), it is suggest that interjurisdictional cooperation will probably be needed to ensure sustainability of the S. platorynchus commercial fishery and the success of A. fulvescens reintroduction in the upper Mississippi River. Additionally, fin‐ray microchemistry can provide invaluable data to make informed management decisions regarding large river fishes, that cross jurisdictional boundaries or that move outside of closure zones, without causing further mortality to compromised fish populations ( e.g. threatened and endangered species).