Abstract
Atlantic tarpon (Megalops atlanticus) are a popular sportfish that make long coastal migrations from the southern Gulf of Mexico to the northern Gulf in the late spring. The species is long lived and slow maturing, which makes them susceptible to the synergistic effects of overfishing and climate change and, as a result, they are currently listed as Vulnerable by the IUCN. Yet, significant gaps remain in our understanding of tarpon space use, movement, and biology, particularly in the northern Gulf of Mexico, which hinders our ability to properly manage the species. From 2018-2019, citizen scientists facilitated the tagging of 23 tarpon with towed SPOT tags in Alabama and Louisiana waters to examine space use and movement across the northern Gulf of Mexico. Specifically, space use was examined using movement-based kernel densities to estimate simplified biased random bridge-based utilization distributions and movement was examined using a joint move persistence model to estimate a behavioral index for each tarpon. Utilization distributions were highest at the southwest portion of the Mississippi River Delta, an area previously predicted as a potential spawning habitat for the species. Tarpon move persistence was highest off the Mississippi and Alabama coasts and lowest in Louisiana waters. Our examination of tarpon space use and movement indicates that the Mississippi River Delta is a critical, yet understudied, part of their range.
