ABSTRACT
At the present time a significant portion of the work with underwater acoustics in ocean monitoring-type studies is in the fields of biological oceanography and fisheries. Currently echo sounders are routinely used for qualitative and quantitative assessment of fish and zooplankton stocks. Most of the quantitative investigations using echo sounders to assess sizes of individuals and numbers of various fishery stocks and euphausiid populations have been combined with more conventional ancillary information provided by nets or trawls. Private, commercial and scientific untilization of echo sounders attest to the reliability and convenience as well as the cost-effectiveness of gathering data. While at this time insufficient work for quantitative studies of mixed assemblages of organisms has been completed, it should be available in the near future. As more information becomes available and the combination of computer processing and acoustic modeling develop together, it is not unreasonable to assume that some day acoustics will supplant other means of qualifying and quantifying distributional information in the ocean.
