Zooplankton (particularly the large calanoid copepods of the genus Neocalanus), salmon fry, pollock, and herring abundances were measured in Prince William Sound from April 18 to June 15, 2001 using multiple-frequency (38, 120 and 420 kHz) acoustic technology combined with optimized plankton net sampling in order to provide scientific guidance to hatchery release strategies, address carrying capacity issues, and evaluate impacts on predator populations.