Abstract Objective An Alligator Gar Atractosteus spatula fishery on the Trinity River, Texas, provided an opportunity for the Texas Parks and Wildlife Department to collaborate with angling guides and evaluate the efficacy of angler-based tagging efforts to inform population management. Methods From 2019 through 2024, guides were provided with tagging and data recording kits and were asked to measure, tag, and release angled Alligator Gar in the Trinity River. Data regarding tag number, total length, and tagging location were recorded. Guide-obtained catch and size structure data were compared to agency-based gill-net sampling to evaluate program efficacy. Recapture data were used to assess fish site fidelity and movement. Site fidelity was assessed as recaptures within 1 km of the original tagging location. Displacement distance was assessed as the furthest upstream or downstream recapture of each fish from its original tagging location over the study duration. Differences in displacement distances between the upper and lower Trinity River reaches (i.e., above or below Livingston Dam) as well as between fish of above-average and below-average sizes were assessed. Results From 2019 through 2024, 3,740 fish were tagged. Guides tagged 3,642 fish caught on rod and reel, and biologists tagged 98 fish caught in gill-net surveys. A total of 218 (5.8%) individual fish were recaptured by guides (n = 213) or found dead (n = 5), along with 27 multiple-recapture events. Utilizing guides to tag fish reduced equivalent agency-based effort by over 97% and yielded similar results for the population size structure of trophy-sized fish (180 cm). Fish were fully recruited to angling at approximately 130 cm and to gill nets at approximately 140 cm. Guides sampled 58–246-cm fish, whereas agency sampling captured 111–242-cm fish. Site fidelity rates were high (90%) throughout the study reach. There were reach- and size-specific differences in displacement distance: Fish of above-average size (153 cm) in the upper reach had the greatest mean displacement distances (mean = 2 km; range = 0–343 km). Conclusions Our investigation illustrates that collaboration between state managers and angling guides can greatly reduce agency labor costs while obtaining comparable data and fostering relationships between state agencies and their constituents. Guide-based tagging efforts may be used to reduce state efforts to estimate size structure and direct research questions into size-specific movement patterns for Alligator Gar. Supplementing agency-obtained data with angler-obtained data may also bolster sample sizes for management efforts.
Radigan et al. (Tue,) studied this question.