Acoustic Methods: Brief Review and Prospects for Advancing Fisheries Research

Acoustic methods are widely used in fisheries research, often providing vital information that can be obtained in no other way. In reviewing active methods, phenomena of sound scattering are first described. The means of ensonification and detection, the generic sonar, is described. Examples include the traditional scientific echo Sounder and the following six classes of sonar: multibeam. sidescan, acoustic lens-based, parametric, synthetic aperture, and conventional low-frequency sonars. Methods of data processing, quantification, and data interpretation are addressed. In reviewing passive methods, sounds produced by organisms are exemplified. The traditional means of detecting sound, the hydrophone, is then described together with Various configurations of hydrophones. Methods of data analysis and classification are outlined. Calibration is addressed separately for sonars and hydrophones. Applications of the various methods are cited. Potential applications of new, improved, or refined acoustic methods to outstanding problems in fisheries and fisheries habitat research are indicated.