Simulation Modeling to Explore the Effects of Length‐Based Harvest Regulations for Ictalurus Fisheries

Abstract

Management of Blue Catfish Ictalurus furcatus and Channel Catfish I. punctatus for trophy production has recently become more common. Typically, trophy management is attempted with length‐based regulations that allow for the moderate harvest of small fish but restrict the harvest of larger fish. However, the specific regulations used vary considerably across populations, and no modeling efforts have evaluated their effectiveness. We used simulation modeling to compare total yield, trophy biomass (Btrophy), and sustainability (spawning potential ratio [SPR] > 0.30) of Blue Catfish and Channel Catfish populations under three scenarios: (1) current regulation (typically a length‐based trophy regulation), (2) the best‐performing minimum length regulation (MLRbest), and (3) the best‐performing length‐based trophy catfish regulation (LTRbest; “best performing” was defined as the regulation that maximized yield, Btrophy, and sustainability). The Btrophy produced did not differ among the three scenarios. For each fishery, the MLRbest and LTRbest produced greater yield (>22% more) than the current regulation and maintained sustainability at higher finite exploitation rates (>0.30) than the current regulation. The MLRbest and LTRbest produced similar yields and SPRs for Channel Catfish and similar yields for Blue Catfish; however, the MLRbest for Blue Catfish produced more resilient fisheries (higher SPR) than the LTRbest. Overall, the variation in yield, Btrophy, and SPR among populations was greater than the variation among regulations applied to any given population, suggesting that population‐specific regulations may be preferable to regulations applied to geographic regions. We conclude that LTRs are useful for improving catfish yield and maintaining sustainability without overly restricting harvest but are not effective at increasing the Btrophy of catfish. Received February 1, 2016; accepted June 16, 2016

Two Decades of Advancement in Flathead Catfish Research

“…2021; Schall and Lucchesi 2021), a finding similar to those of modeling studies examining other ictalurid species (Stewart et al. 2016). However, regulations can be effective at changing Flathead Catfish populations under some conditions.…”

Saving large fish through harvest slots outperforms the classical minimum‐length limit when the aim is to achieve multiple harvest and catch‐related fisheries objectives

“…Other models have accounted for some of these processes, but these models were calibrated to specific species (e.g. northern pike, Esox lucius , Esocidae, Arlinghaus et al, ; brown trout, Salmo trutta , Salmonidae, Ayllón et al, ; catfishes of the genus Ictalurus , Ictaluridae, Steward, Long, & Shoup, ; lake trout Salvelinus namaycush , Salmonidae, Lenker, Weidel, Jensen, & Solomon, ; or walleye, Sander vitreus , Percidae, Moreau & Matthias, ), and the results thus lacked generality. Importantly, none of the cited studies have systematically asked which harvest policy is optimal given a spectrum of fishery objectives.…”

Reproductive Characteristics Differ in Two Invasive Populations of Blue Catfish

“…Population‐specific differences in life history traits have prompted other researchers to also call for population‐specific regulations for Blue Catfish (Stewart et al. 2016). Finally, many populations of Blue Catfish in Atlantic slope drainages, including those in the upper portion of the Chesapeake Bay, likely form metapopulations, which can contribute recruits to nearby systems (Higgins 2006; Nepal and Fabrizio 2019).…”