Natural Resources, School of
Date of this Version
4-2011
Abstract
Channel catfish Ictalurus punctatus and flathead catfish Pylodictis olivaris are two of the most important freshwater recreational or commercial species in the United States. Catfish populations in the Missouri River are important resources to the people of Nebraska and surrounding states. The objective of my study was to determine the present status of catfish populations in the Missouri River, Nebraska. Specifically I evaluated population characteristics such as relative abundance, population size and density, size structure, condition, age structure, growth, and mortality. I used a stratified random sampling design and generalized linear mixed modeling approach to assess differences in population characteristics between segments of the Missouri River, Nebraska and a closed-captures capture-mark-recapture study to estimate density and abundance of channel catfish > 200 mm within a Missouri River, Nebraska study bend. Growth rates of channel catfish and flathead catfish in the Missouri River, Nebraska are relatively slow compared to species’ standards but are similar to those observed in other Nebraska Rivers. Differences in population characteristics between segments of the Missouri River, Nebraska suggest that catfish management in this portion of the Missouri River appears to be well suited for management unit based regulations. Specifically, the upper channelized segment has a relatively greater density channel catfish population and appears to be able to support relatively greater levels of channel catfish harvest than the other segments. Similarly, the lower channelized segment has a relatively greater density flathead catfish population and appears to be able to support relatively greater levels of flathead catfish harvest than the other segments. The upper unchannelized segment appears to support low density populations of channel catfish and flathead catfish that may be better suited for trophy management regulations designed to minimize harvest and maximize growth potential.
Advisor: Mark A. Pegg
[Updated -- corrections to data table -- 6/28/2011]
[Updated -- errata -- 11/18/2011]
Comments
A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Natural Resource Sciences, Under the Supervision of Professor Mark A. Pegg. Lincoln, NE: April 2011
Copyright 2011 Cameron W. Goble