Size‐Specific Exploitation of Flathead Catfish and Blue Catfish by Recreational and Commercial Fishers in the Missouri and Mississippi Rivers, Missouri

Size‐selective harvest in a fishery is a growing point of contention among different catfish anglers. In response to these concerns, size‐specific exploitation rates of Flathead Catfish Pylodictus olivaris and Blue Catfish Ictalurus furcatus by recreational anglers and commercial fishers were quantified. Eight study reaches were randomly selected on the Missouri River (4 reaches; recreational harvest only) and the Mississippi River (4 reaches; recreational and commercial fishing allowed). Fish were captured by electrofishing in 2015 and 2016 and were tagged with Carlin dangler reward tags. A total of 3,370 tags were distributed among 12 size‐groups starting at 381 mm TL, of which 609 tags were reported during the study period. High‐reward (US$150) tags were used to estimate nonreporting of standard ($25) tags. Reporting rates varied by reach and constituency group and ranged from 19% to 100%. Overall exploitation rates of Flathead Catfish were comparable to those in other studies (0.10–0.19) but were highly variable among sizes and among reaches. Commercial fishers did not harvest any fish smaller than 584 mm, and they tended to be more size selective than recreational anglers. Exploitation of Blue Catfish by recreational anglers was highest for 840–890‐mm fish (0.34–0.43) in the Missouri River and for 891–1,015‐mm fish (0.24–0.28) in the Mississippi River. Commercial harvest of Blue Catfish was not significantly different among size‐groups and was much lower than recreational harvest. These data indicated that recreational anglers and commercial fishers were often selective for mid‐ to larger‐size fish rather than for small sizes. Understanding the levels and potential range of size‐specific exploitation of catfish in larger rivers will aid managers when setting appropriate regulations and balancing the competing objectives of these fisheries.