Shovelnose sturgeon (Scaphirhychus platorynchus) movements in the Wabash river, Indiana

Michael David Wellman, Purdue University

Abstract

The Wabash River, Indiana supports an important population of shovelnose sturgeon, the only sturgeon of the North American genus Scaphirhynchus not currently listed as endangered. Telemetry was used to identify habitat use, understand seasonal migrations, and recognize small-scale movement patterns of this unique population. During the spring of 2009, 30 shovelnose sturgeon, 15 males and 15 females, from the middle Wabash River were implanted with ultrasonic transmitters. Manual tracking was conducted near Lafayette, Indiana, and six passive receivers were deployed throughout the river to monitor large scale movement. In addition to shovelnose sturgeon implanted and tracked, 60 fish were used the following summer to establish if the surgery and implantation of the ultrasonic tags influenced survival. These 60 fish were assigned to control and experimental treatments, monitored for 30 days in culture ponds, and assessed for tag loss. Results from the tracking indicate site fidelity of sturgeon during the spring spawning period and a potential for long distance, post-spawn migrations of at least 320 kilometers by males. Most tagged shovelnose sturgeon were no longer observed in the spawning area by the end of June, suggesting the end of the spring spawning period. Survival of control and experimental fish in the ponds yielded lower than anticipated numbers, but it was determined that mortality was driven by a pond effect and not by the surgery and implantation process. Also, five of 30 implanted shovelnose sturgeon exhibited tag loss. This work was able to identify important habitat use of shovelnose sturgeon during the spawning period, the species' sedentary activity while in the spawning area, large post-spawn movements by males, and the suitable survival of shovelnose sturgeon implanted with dummy ultrasonic transmitters. However, further study of female shovelnose sturgeon post-spawn movements and mortality associated with internal tagging is needed. With increased commercial harvest possible in the Wabash due to recent legislation, these findings can be used to help protect the population and supplement future work.

Degree

M.S.

Advisors

Goforth, Purdue University.

Subject Area

Aquatic sciences

COinS