Degree Type

Thesis

Date of Award

2008

Degree Name

Master of Science

Department

Natural Resource Ecology and Management

First Advisor

Michael Quist

Second Advisor

Clay Pierce

Third Advisor

Philip Dixon

Abstract

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.

DOI

https://doi.org/10.31274/rtd-180813-16070

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Jeff Koch

Language

en

Proquest ID

AAI1453060

OCLC Number

236986657

ISBN

9780549540960

File Format

application/pdf

File Size

78 pages

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