ABSTRACT
This chapter explains the use of low-cost and relatively simple methods for using acoustics in stock assessment. Applications are drawn from developing country small-scale fisheries and smaller, temperate water fisheries. A major focus of fisheries acoustics is the estimation of fish abundance both for immediate use and for use as auxiliary information in larger stock assessment analyses. Acoustic methods efficiently detect and quantify fish but provide little fish size and species information. To use the acoustic survey effectively for the stock assessment of a target group of species, one should have a good idea of the areas occupied by that species. The chapter lays a foundation for the analysis and use of single-beam methods, including deconvolution. It presents some of the theory underlying fisheries acoustics. A fisheries research acoustic system typically consists of transmitter, receiver and signal processor. Target strength has been called the key quantity in the acoustic assessment of fishes.
