Date of this Version
Channel catfish Ictalurus punctatus is an important sport fish, particularly in the Great Plains. In Nebraska, a majority of anglers target channel catfish, and fishing activities are a vital part of the state’s economy. Lentic water bodies provide the primary fishing opportunity for catfish anglers in Nebraska. Despite the popularity and economic importance of channel catfish, little is known of its population dynamics or habitat requirements, and existing studies often profile river populations. Current standards for sampling channel catfish in lentic systems often yield inadequate catch to assess populations. The objective of this study was to utilize a recently developed sampling method, tandem-set hoop nets, to collect channel catfish in sufficient quantities to describe the effects of stocking and habitat variability on populations in lentic ecosystems. Three lentic ecosystems common to the Great Plains were considered: sand pits, flood-control reservoirs, and irrigation/power-generation reservoirs. The influence of stocking on abundance and condition of channel catfish varied with ecosystem type. In sand pits, stocking negatively influenced fish condition, and only frequent stocking positively influenced abundance. In flood-control reservoirs, stocking did not influence fish condition, but was associated with greater abundance. Stocking did not influence fish condition or abundance in irrigation/power-generation reservoirs. Additionally, there was evidence that mortality and growth rates varied with ecosystem type. In general, populations from irrigation/power-generation reservoirs were predicted to experience slower growth and lower mortality, whereas populations from sand pits were predicted to experience the fastest growth and highest mortality. Catch rates of channel catfish were substantially less in this study compared to previous records of tandem-set hoop net surveys, but hoop nets were more efficient than the current standard gear, experimental gill nets, at capturing channel catfish (i.e., 100 fish could be captured with fewer hoop net sets than gill net sets). However, catch rates and size structure of channel catfish in tandem-set hoop nets varied within the sampling season and between years. Furthermore, length-frequency distributions of channel catfish were dissimilar between hoop nets and gill nets.
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