Maturity Schedules of Female American Shad Vary at Small Spatial Scales in Chesapeake Bay

Recent assessments of American shad Alosa sapidissima have used stock-specific maturity schedules in biomass-per-recruit models to establish benchmark total mortality rates for management. Because stocks of American shad are managed separately, an appropriate maturity schedule for each stock is required. Additionally, projections of adult biomass require knowledge about year-class strength and the maturation process. Changes in age at maturity can occur when strong year-classes enter the spawning stock; such changes may affect stock assessment models and management decisions. Maturity schedules may also change due to fishing or other external factors. If stock-specific maturity patterns exist, then identical fishery regulations could have different impacts on neighboring stocks. Most American shad matured by age 5 in this study, with year-class-specific estimates of the percentage mature ranging from 46% to 80% in the James River, 58% to 79% in the Rappahannock River, and 49% to 82% in the York R...