Modeling the Responses of Alligator Gar Populations to Harvest Under Various Length-based Regulations: Implications for Conservation and Management

Abstract

AbstractInterest in managing Alligator Gar Atractosteus spatula populations as a unique sport fishery has increased over the past decade, but despite this interest, population responses to harvest are poorly understood. Fishing regulations for Alligator Gar vary throughout their distribution; however, to date most regulations have focused on a daily creel limit. We developed an age-structured dynamic-pool model in R to, (1) quantify population level effects of exploitation, and (2) evaluate how these effects were altered under a suite of length-based fishing regulations. The model was parameterized based primarily on empirically estimated dynamic rates for Texas Alligator Gar populations. For each model scenario, we calculated the mean and variance of the number of trophy fish in the population, the population size, Spawning Potential Ratio (SPR), and the fishery yield over a 100-year chronology. Alligator Gar populations were highly sensitive to exploitation in our model simulations. An exploitation rate...