Shovelnose Sturgeon Recruitment Sources and Inter-River Movement of Shovelnose and Lake Sturgeons in Pools 20-26 of the Upper Mississippi River: Implications for Sturgeon Conservation

Sturgeon populations in North America are at risk due to habitat degradation and overharvest.  In the Upper Mississippi River, Lake Sturgeon are maintained by stocking, whereas Shovelnose Sturgeon are naturally reproducing and may be legally commercially harvested.  Sturgeons that inhabit the Upper Mississippi River may also potentially use other interconnected river reaches during a portion of their lifetimes. However, the relative importance of different river reaches as natal environments for Shovelnose Sturgeon present in the Upper Mississippi River is unknown, and knowledge of the frequency of sturgeon movement among these interconnected rivers is limited. We sought to reconstruct movement patterns of stocked Lake Sturgeon and wild Shovelnose Sturgeon, and to determine natal environment of Shovelnose Sturgeon collected from the Upper Mississippi River using fin ray Sr:Ca. The majority Shovelnose Sturgeon captured in the Upper Mississippi River originate from locations outside the UMR (Missouri River, Middle Mississippi River); whereas, Lake Sturgeon exhibit infrequent movement outside of the Upper Mississippi River, but may move throughout these interconnected large rivers at various life stages. Thus, interjurisdictional cooperation will likely be needed to ensure sustainability of the Shovelnose Sturgeon commercial fishery and the success of Lake Sturgeon reintroduction in the Upper Mississippi River.