The First Genetic Analysis of the Pamunkey River, Virginia Atlantic Sturgeon (Acipenser oxyrinchus) Spawning Population

On February 6, 2012, the National Marine Fisheries Service listed five distinct population segments of Atlantic sturgeon as threatened and endangered under the Endangered Species Act relying on the discreteness and significance of the genotypes of 12 spawning populations. When listed, the only known spawning population in the Chesapeake Bay was in the James River, but the discovery of a spawning population in the Pamunkey River, a tributary to the York River, allowed us to conduct a genetic analysis of these new individuals compared with other populations along the East Coast. The York River population is in Hardy-Weinberg equilibrium, but falls out of equilibrium when combined with any other populations. Homing fidelity to this system is approximately 95% and the population contains two unique alleles that are fairly common in the population. A STRUCTURE analysis suggests this population is distinct from any other known sturgeon populations. Because this population is listed under the Endangered Species Act as part of the Chesapeake Bay DPS, it is important for managers to know this population is small, genetically isolated, and distinct from other populations along the coast in order to appropriately protect these individuals and their unique alleles.