We examined conditions under which white shrimp ( Litopenaeus setiferus ) post‐larvae enter an estuarine channel receiving high freshwater discharge and one receiving negligible discharge in the Ossabaw Sound system of Georgia, USA, during 1997 and 1998. We used surface nets to collect plankton over several 14‐day periods, during which consecutive tows were made at night against the flooding current at stations in the inlet ch...