Comparison of Channel Catfish Populations in Channeled and Unchanneled Sections of the Little Sioux River, Iowa

Comparisons are made of channel catfish in channeled and unchanneled sections of the Little Sioux River with regard to abundance, movement, and age and growth. Mean catches per unit effort of channel catfish were higher during May to October bi-weekly periods in the unchanneled section. Movement was predominantly downstream in both areas. In the unchanneled section 23.7% moved upstream, 69.6% moved downstream, and 6.7% were recaptured at their release site. In the channeled area 25.8% moved upstream, 39.8% moved downstream and 34.4% were recaptured at their release site. Due to the free exchange of catfish between both areas, growth rates were similar in both areas. The largest mean annual increment in both areas (4.42 inches) occurred in the second year