Acoustic surveying of pelagic fish in shallow water

The acoustic monitoring program at the Prince William Sound Science Center is used to illustrate the application of acoustic techniques to surveying pelagic fish biomass. The herring population in Prince William Sound, Alaska, collapsed after the Exxon Valdez Oil Spill in 1989. Fishery-dependent information was not adequate either to halt the collapse or to understand its ramifications. Fishery-independent observational techniques like acoustics not only provide more timely information for management, but also provide additional information on other components of the ecosystem. After the herring collapse, information from acoustic surveys in Prince William Sound was used to show that both the oil spill and overfishing contributed to the collapse, and the loss of critical forage resulted in parallel declines of many seabirds and marine mammals, including the endangered Steller sea lion.