Cooperative Fish and Wildlife Research Units Program: Oklahoma
Education, Research and Technical Assistance for Managing Our Natural Resources

Stewart, D.R. and J.M. Long. 2016. Using an experimental manipulation to determine the effectiveness of a stock enhancement program. Journal of Freshwater Ecology 31:37-52.


We used an experimental manipulation to determine the impact of stocking 178-mm channel catfish Ictalurus punctatus in six large impoundments. The study design consisted of equal numbers (two) of control, ceased-stock, and stocked treatments that were sampled one year before and two years after stocking. Relative abundance, growth, size structure and average weight significantly changed over time based on samples collected with hoop nets. Catch rates decreased at both ceased-stock lakes and increased for one stocked lake, while growth rates changed for at-least one ceased-stock and stocked lake. The average weight of channel catfish in the ceased-stock treatment increased by 18 g and 365 g, whereas weight decreased by 274 g and 953 g in the both stocked lakes. The variability in observed responses between lakes in both ceased-stock and stocked treatments indicate that a one-size-fits-all stocking agenda is impractical, suggesting lake specific and density-dependent mechanisms affect channel catfish population dynamics.