Identification Of Critical Habitat and Spawning Migrations Of Atlantic Sturgeon Acipenser Oxyrinchus Oxyrinchus In The Altamaha River System, Georgia

The Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus, Aciperseridae) has declined throughout its range as a result of various anthropogenic factors and the species is now protected under the United States Endangered Species Act. Information on spawning migrations and spawning habitat is essential for effective recovery plans for Atlantic sturgeon. The objectives of our study were to document and describe (1) seasonal distribution and movements and (2) spawning migrations.  We used a stationary array of acoustic receivers to monitor the movements of 30 adult Atlantic sturgeon in the Altamaha River system, Georgia, from April 2011 through March 2013. Telemetry data revealed that adult Atlantic sturgeon appeared to stage in the oligohaline habitats of the lower Estuary during the spring and early summer.  In fall, the fish migrated at least 250 rkm upriver to suspected spawning habitats in Ocmulgee River, returning back to the ocean during the following winter.  Similar studies of Atlantic sturgeon in northern river systems showed that spawning typically occurs in late spring and early summer.  Our findings on the Altamaha River illustrate the clinal variation in the life history of Atlantic sturgeon and highlight the need to manage the species as distinct population segments with regionally specific recovery goals.