Date of Award
Master of Science
Natural Resource Ecology and Management
Shovelnose sturgeon Scaphirhynchus platorynchus have become an increasingly important commercial species in the upper Mississippi River (UMR) due to collapsing foreign sturgeon populations and bans on imported caviar. In response to concerns about the sustainability of the shovelnose sturgeon fishery in the UMR, we began this study to describe shovelnose sturgeon population demographics and evaluate the influence of commercial harvest on shovelnose sturgeon populations in the UMR. A total of 1,682 shovelnose sturgeon were collected from eight study pools of the UMR in 2006 and 2007 (i.e., Pools 4, 7, 9, 11, 13, 14, 16 and 18). Shovelnose sturgeon from upstream pools generally had greater lengths, weights, and ages than shovelnose sturgeon from downstream pools. Additionally, mortality estimates were also lower in upstream pools (i.e., Pools 4, 7, 9, and 11) compared to downstream pools (i.e., Pools 13, 14, 16, and 18). Analyses indicated that decreased growth of shovelnose sturgeon may be a consequence of commercial harvest in the UMR. Modeling of potential management scenarios suggest a 27-inch minimum length limit is necessary to prevent growth and recruitment overfishing of shovelnose sturgeon in the UMR.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Koch, Jeff, "Effects of commercial harvest on shovelnose sturgeon populations in the upper Mississippi River" (2008). Retrospective Theses and Dissertations. 14926.