Gulf Sturgeon of the Pascagoula River: Post-Katrina Assessment of Seasonal Usage of the Lower Estuary

The Pascagoula watershed likely offers the greatest possibility for the survival of the Gulf sturgeon, Acipenser oxyrinchus desotoi within Mississippi. The focus of this project was to determine the routes Gulf sturgeon take through the lower Pascagoula River which splits at river kilometer 23 into two distinct distributaries. Sampling for this project was conducted over 60 d in 11 months throughout a two year period with a total of 81,947 net-meter-hours. Eight Gulf sturgeon were captured during this time and ranged in size from 81 - 196 cm TL and weight ranged from 3.6 - 52.6 kg. Using an array of automated telemetry receivers, ultrasonic tagged Gulf sturgeon migrations were monitored within the lower river and associated estuary. Data gathered by the automated telemetry array indicated that Gulf sturgeon movements through the project area are dissimilar between and among size classes, as some fish followed the most parsimonious route while others moved in more complex patterns. Based on the movements documented in this study, Gulf sturgeon appear to prefer the eastern distributary upstream from Bayou Chemise as the primary travel corridor between freshwater habitats and marine feeding grounds. The western distributary mouth was more highly utilized by Gulf sturgeon during seasonal migrations. Interpolated habitat maps of sediment composition and macrofaunal abundance reveal that this area possesses both abiotic and biotic characteristics most commonly reported for foraging Gulf sturgeon relocations from other Gulf sturgeon populations, and this area may represent the closest nearshore foraging grounds available to Gulf sturgeon of the Pascagoula River