Sturgeon and Paddlefish Migration: Evidence to Support the Need for Interjurisdictional Management

Paddlefish Polyodon spathula and three sturgeon species are present in the upper Mississippi River; of these four species, two are commercially and recreationally important (Paddlefish and Shovelnose Sturgeon Scaphirhynchus platorynchus), and two are protected under federal or state endangered species laws (Pallid Sturgeon S. albus and Lake Sturgeon Acipenser fulvescens). Before management strategies can be implemented, quantification of movement patterns is necessary to determine the appropriate spatial scale for management. To increase the available relevant information, we investigated broad‐scale movement patterns of the above species in the upper Mississippi River by using telemetry. All four species were capable of long‐range (>300‐km) movements, and these movements were cued by the changing river stages and water temperature. Ultimately, our data suggest that sturgeon and Paddlefish movement patterns are highly variable, with fish moving freely among rivers (e.g., the Mississippi, Missouri, Illinois, Ohio, and Des Moines rivers) across many political boundaries and encompassing multiple regulatory agencies. This migratory nature can lead to portions of the population being subject to harvest in multiple management units, affecting population dynamics, biology, harvest, and management/recovery in both the natal area and in the harvest areas. To effectively manage or recover these highly mobile fish populations, interjurisdictional collaboration will be necessary.