Evaluation of Alligator Gar Hooking and Delayed Capture Mortality Using Juglines in the Red River, Arkansas

Abstract

Hooking and delayed mortality rates are poorly documented for capture of alligator gar (Atractosteus spatula) with standard sampling gears and fishing tackle. A recent study documented over 81% hooking mortality for alligator gar captured from Lake Texoma, Oklahoma, using overnight jugline sets with treble hooks. The Arkansas Game and Fish Commission uses active-set juglines rigged with 3-prong treble hooks to conduct alligator gar population assessments. We evaluated hooking and delayed capture mortality of alligator gar by using juglines set with either treble or circle hooks. Twenty-nine alligator gar were captured from a 16-km segment of the Red River, Arkansas. Twenty-two individuals were caught using treble hooks and seven were caught using circle hooks. Two fish expired prior to translocation from hooking-related injuries. Surviving fish were translocated and held in a nearby 3.2-ha observation pond for 18 to 24 days post-capture. Of fish caught using treble hooks, 64% were internally hooked, compared to 29% of those caught using circle hooks. Hooking mortality was 7% regardless of anatomical hooking location or hook type. Mortality of fish caught with treble and circle hooks was 5% and 14%, respectively. Of the 27 successful alligator gar translocations, one died during the observation period, presumably from handling procedures as the necropsy revealed no hooking-related injuries. However, delayed mortality due to hooking was not observed. Three fish died during this study because of either hooking or handling factors, resulting in a 10% total mortality rate. Although this is reasonably low, long-lived species with periodic life-history strategies are extremely sensitive to mortality. Alligator gar managers need to consider the impact mortality may have on populations when abundance is uncertain or low and select a sampling gear within those mortality thresholds. Based on our results, utilizing internal hooking methods should only be used when abundance is great enough to sustain some level for sampling mortality.