Eder to defend master's thesis

Missouri River
Missouri River

Brandon L. Eder, graduate student, will defend his thesis, "Management of Channel Catfish in the Missouri River, Nebraska," at 1 p.m., Nov. 24 in the Hardin Hall auditorium (room 107). His adviser is Mark Pegg.

Abstract:

The popularity of catfish Ictaluridae nationally as a sport fish is well documented and angling for catfish on the Missouri River in Nebraska (NMR) is especially popular. A catfish monitoring by the Nebraska Game and Parks Commission (NGPC) began in 1974 and short-term evaluations of Channel Catfish population dynamics have been performed. However, no long term analyses of population characteristics have been conducted since the early 1990s. The focus of this research was to summarize the status of Channel Catfish populations in the NMR and give recommendations for future management.

I summarized population characteristics, modeled length limit regulations, and assessed the feasibility of a survey design aimed at gathering effort and catch data from setline anglers. Population characteristics varied among the four reaches studied. Channel Catfish in the upper unchannelized reach had relatively low mortality, moderate population densities and a long life span. The lower unchannelized reach had a population of small, slow growing Channel Catfish with high mortality rates. Population characteristics in the upper channelized reach were similar to those of the LU except relative abundance was greater. The lower channelized reach had the highest mortality and the fastest growing, shortest lived fish in the study. Modeling revealed all reaches except the lower unchannelized reach could benefit from a 380-mm minimum length limit. In all cases, mean total length, mean weight, and yield would increase with a minimum length limit. A maximum length limit would likely not be effective for growing trophy sized fish in the upper unchannelized reach. Setlining is an unknown aspect of the Missouri River catfish fishery. Methods described in this study appear to be a feasible alternative to creel surveys for estimating setline effort and catch.