Evidence of Atlantic Sturgeon Spawning in the York River System

The National Marine Fisheries Service listed five distinct population segments of Atlantic Sturgeon Acipenser oxyrinchus as threatened and endangered under the Endangered Species Act on February 6, 2012. At that time, the only known spawning population of sturgeon in the Chesapeake Bay was in the James River. The goal of this research was to determine whether reproduction was also occurring in the Chesapeake's York River watershed. Based on the assumption that an early fall spawning event occurs in the upper reaches of the watershed, these waters were sampled in late August of 2013 when water temperatures became appropriate for spawning. During a week of sampling, numerous male sturgeon running milt and one spawned-out female with residual eggs still present were captured. The co-occurrence of reproductively active males and a recently spawnedout female Atlantic Sturgeon in the upper Pamunkey River at temperatures consistent with documented spawning temperatures in other systems indicates that fall spawning occurs in the York River system. Therefore, the population segment of Atlantic Sturgeon distinct to the Chesapeake Bay has at least two spawning populations that managers should consider when protecting this listed species.