Variable production of young striped bass Morone saxatilis in the estuarine transition region depends on environmental and hydrographic conditions in the estuarine turbidity maximum (ETM) and salt front region of Chesapeake Bay. Spatio-temporal variability in occurrence, growth, and diet of early life stages of striped bass and zooplankton prey were compared in years of average (2007) and poor (2008) production of striped bass juveniles. Stable isotope analyses tracked sources of carbon and nitrogen in larval striped bass diets. The estuarine copepod Eurytemora affinis was the most important prey. It and the freshwater cladoceran Bosmina longirostris dominated diets of striped bass larvae. Bosmina was relatively important in 2007. Larvae grew faster in 2007 than in 2008 and growth was fastest within and up-estuary of the ETM and salt front. Stable isotope analysis indicated that carbon from both marine and terrestrial sources supports production of striped bass larvae.