Spawning and Associated Movement Patterns of Gulf Sturgeon in the Pascagoula River Drainage, Mississippi

Abstract

Gulf sturgeon Acipenser oxyrinchus desotoi are federally listed as threatened, the principal reasons for population declines being habitat loss due to dams, overfishing, and water quality deterioration. The timing of freshwater migration and the locations and habitat features of spawning areas are undocumented for Gulf sturgeon in the Pascagoula River drainage. Our objectives were to identify and characterize spawning areas, determine spring movement patterns, and document homing fidelity by gill netting and radio-tracking. Through collection and rearing of Gulf sturgeon eggs, we verified that the Bouie River north of Hattiesburg, Mississippi (250 river kilometers upstream from the mouth of the Pascagoula River), is a spawning area. We also documented homing fidelity in the Bouie River using radiotelemetry and capture data. Prolonged residence and overwintering of Gulf sturgeon were observed near the Bouie River spawning area. This behavior may be caused by the modified nature of this portion of the Bouie River, which includes deep, in-channel gravel pits. Spawning habitat was located in an upstream reach that consisted of hard substrata and gravel with turbulent, high flow. The spawning area on the Bouie River and access to it are vitally important for this species in Mississippi.