Spawning Drivers of Female Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus) in the James River: A Fine-Scale Temporal Analysis

Abstract

Fall-run Atlantic Sturgeon occupy riverine habitat for extensive periods of up to several months during periods of spawning. It is generally not feasible to eliminate potential anthropogenic stressors during the entire time Atlantic Sturgeon are on spawning habitat. If data were available to accurately predict when eggs and larvae are in the water column, potential impacts could be minimized for this relatively short timeframe, compared to the entire season of freshwater residency by adults. This research used acoustic telemetry data for adult female sturgeon, along with water temperature and discharge, to predict when females were likely releasing eggs versus merely staging in spawning habitat waiting to spawn. The descriptive and Bayesian model results predict that egg release is associated with water temperatures ranging from 20-26{degrees}C and pulses in river discharge, often confining egg release to a few days or weeks. By using weather data that predict relatively short periods of when egg release occurs versus longer periods that includes staging, resource managers can more feasibly collaborate with water usage groups to ameliorate egg/larvae survival.