Using Creel Data to Evaluate Blue and Channel Catfish Aggregate Harvest Regulations for Texas Reservoirs

Abstract

AbstractThe Texas Parks and Wildlife Department’s strategic management plan for catfishes (Ictaluridae) called for the development of alternative harvest regulations for Blue Catfish Ictalurus furcatus and Channel Catfish I. punctatus. Angler harvest of these species in most Texas reservoirs has been regulated using a 305‐mm minimum length limit (MLL) and a 25‐fish aggregate daily bag limit (DBL) since 1995. Using existing creel data collected in 2003–2018 at 86 Texas reservoirs managed under this statewide harvest regulation, we examined Blue and Channel Catfish harvest size structure and composition, percent release of legally harvestable‐size fish, and harvest density (number and biomass). Additionally, for reservoirs having long‐term creel data, we evaluated temporal change in percent release of legally harvestable‐size fish and harvest size structure, and we estimated the impact of alternative harvest regulations by using a theoretical harvest reduction (THR) model. Channel Catfish were the predominant species harvested (>75% of harvest) in 63% of the reservoirs. Harvest size structures of Blue and Channel catfish differed, but the difference in percent harvest of fish smaller than 406 mm was negligible (52% and 48%, respectively). Percent release of legally harvestable‐size fish (≥305 mm) was low at most reservoirs (median = 13%). Total number of catfish harvested per hectare per quarter (HHQ) ranged widely (0.0–11.3) but was less than 1.0 at 58% of reservoirs. Harvest size structure was truncated over time coincident with a high harvest level (HHQ > 3.0) at two of four reservoirs with long‐term data, suggesting growth overfishing. The THR model revealed that increases in MLL resulted in variable harvest reductions among reservoirs and that removal of the 305‐mm MLL could increase harvest by 6–39%. Additionally, we found that length‐graduated DBLs would have a negligible impact on reducing the harvest of larger fish. We suggest that MLLs are not necessary for most Texas catfish fisheries and that a 356‐mm MLL may be appropriate for high‐harvest fisheries.