Efficacy and Temporal Capture Patterns of Bank Poles in the Kansas River: A Novel Sampling Tool for Catfish

Abstract

AbstractSetlines and trotlines are useful tools for sampling catfish populations. These gears offer an alternative to sampling in habitats or conditions that are unsuitable for traditional sampling gears, and they may be capable of sampling a different subset of the population. However, little is known about their efficacy as catfish sampling gear. We developed a standardized method for deploying setlines in the form of bank poles and assessed the catch rate, species composition, and efficacy of bank poles in the Kansas River, Kansas. We also used Lindgren‐Pitman hook timers to investigate temporal patterns of capture, retention rates, and optimal soak duration. Bank poles (n = 897) were equipped with 6/0 circle hooks baited with Silver Carp Hypophthalmichthys molitrix cut bait and were deployed overnight during the summers of 2018 and 2019. Bank poles captured a total of seven fish species, with 97% of the species composition being catfishes (n = 258; mean TL = 688 ± 182.7 mm; range = 392–1,310 mm). Blue Catfish Ictalurus furcatus (45%) was the most commonly captured species, followed by Channel Catfish I. punctatus (37%) and Flathead Catfish Pylodictis olivaris (15%). The success rate for hooking and landing fish with bank poles was 29%. There was no difference between total catch rates from standard bank poles and those from bank poles equipped with hook timers. Higher catch rates were observed early in the set time for Channel and Flathead catfish, whereas a relatively steady catch rate was observed for Blue Catfish. Overall, 46% of catfish were caught within 3 h of gear deployment and 72% were caught within 5 h. We recommend adopting shortened soak durations (about 5 h) to prevent bait loss and to optimize fish retention. Our study provides an alternative sampling approach to increase the catch of large individuals and offers insight into the catch dynamics and interactions of passive angling gears.