Paddlefish Population Characteristics of Large Midwestern U.S. Rivers

Freshwater river ecosystems have experienced many modifications for flood control and to maintain navigation.  Due to these habitat modifications coupled with overexploitation, fishes have experienced population declines throughout large rivers.  Paddlefish, a migratory megafish native to large rivers, are an example of a species experiencing population declines.  Despite this, paddlefish populations have not been fully evaluated.  Thus, the objective of this study was to assess demographic information for paddlefish in the Mississippi River Basin, as well as to evaluate the current reproductive potential of the population.  At the current total annual mortality rate of 34.5% of pooled locations, the population may experience recruitment overfishing at a 610 and 710 mm minimum length limit.  However, at an 810 mm minimum length limit the population may not experience recruitment overfishing until ~46% total annual mortality.  As such, a basin wide minimum length limit of at least 810 mm is suggested.  Ultimately, managing this megafish on a basin wide approach and considering the Mississippi River Basin as a Mississippi River Swimway will allow managers to provide a sustainable fishery for present and future generations across the entire Mississippi River Basin.