Assessment of the seasonal usage of the lower Pascagoula River estuary by Gulf sturgeon (Acipenser oxyrinchus desotoi)

• Published in: Journal of applied ichthyology Vol. 28; no. 5; pp. 681 - 686
• Main Authors: Havrylkoff, J.-M., Peterson, M. S., Slack, W. T.
• Format: Journal Article
• Language: English
• Published: Berlin Blackwell Publishing Ltd 01.10.2012; Wiley Subscription Services, Inc
• Subjects: Acipenser; Acipenser oxyrhynchus; Brackish; Freshwater; USA, Mississippi, Pascagoula R; ASW, USA, Mississippi
• ISSN: 0175-8659; 1439-0426
• DOI: 10.1111/j.1439-0426.2012.02056.x

Summary The Pascagoula watershed likely offers the greatest possibility for the survival of the Gulf sturgeon, Acipenser oxyrinchus desotoi, within Mississippi. Thus, understanding and preserving the connectivity between distant habitats in this region plays a major role in protecting and managing such anadromous fish populations. The focus of this project was to determine the within‐river routes Gulf sturgeon take through the lower Pascagoula River downstream of the point where it splits (river kilometer 23) into two distinct distributaries. Sixty days were sampled throughout a two‐year period with a total effort of 81 947 net‐meter‐hours and eight Gulf sturgeon were captured, ranging from 74 to 189 cm FL and weighing from 3.6 to 52.6 kg. Using an array of automated telemetry receivers, acoustically tagged Gulf sturgeon movements were monitored within the lower river and associated estuary. Estimated residence times (days) suggest Gulf sturgeon appear to prefer the eastern distributary upriver from Bayou Chemise as the primary travel corridor between freshwater habitats and marine feeding grounds. The western distributary mouth was more highly used by Gulf sturgeon during both seasonal migrations between upriver and offshore habitats. Thus, the western distributary appears to represent the main entrance point utilized by Gulf sturgeon to the Pascagoula River watershed and should be protected as the eastern distributary mouth has been altered from a natural marsh edge to one of hardened surfaces.