%0 Journal Article
%T The Development of SONAR as a Tool in Marine Biological Research in the Twentieth Century
%A John A. Fornshell
%A Alessandra Tesei
%J International Journal of Oceanography
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/678621
%X The development of acoustic methods for measuring depths and ranges in the ocean environment began in the second decade of the twentieth century. The two world wars and the ¡°Cold War¡± produced three eras of rapid technological development in the field of acoustic oceanography. By the mid-1920s, researchers had identified echoes from fish, Gadus morhua, in the traces from their echo sounders. The first tank experiments establishing the basics for detection of fish were performed in 1928. Through the 1930s, the use of SONAR as a means of locating schools of fish was developed. The end of World War II was quickly followed by the advent of using SONAR to track and hunt whales in the Southern Ocean and the marketing of commercial fish finding SONARs for use by commercial fisherman. The ¡°deep scattering layer¡± composed of invertebrates and fish was discovered in the late 1940s on the echo sounder records. SONARs employing high frequencies, broadband, split beam, and multiple frequencies were developed as methods for the detection, quantification and identification of fish and invertebrates. The study of fish behavior has seen some use of passive acoustic techniques. Advancements in computer technology have been important throughout the last four decades of the twentieth century. 1. Introduction During the twentieth century, the use of acoustics to study life in the oceans was developed into a significant tool for research in marine biology. The purpose of this paper is to briefly recount the process by which the use of acoustics as a biological research tool took place. The general pattern was the development of acoustic technology for nonbiological research uses, navigation and military operations to name two and then the application of that technology to the detection and study of marine life. By the end of the twentieth century, acoustic technology had become a significant factor in marine biological research. Marine biologists were developing acoustic equipment for the specific purpose of studying life in the oceans. The development of modern acoustic technologies for use in the ocean environment began during the second decade of the twentieth century. The First World War provided a significant stimulus for the advancement of ocean acoustics research. Following the war, active acoustic ranging devices in the form of echo sounders began to be employed in measuring ocean depths. Soon, acousticians began to recognize the ability to detect marine organisms, principally fish, using these devices. The use of sound to detect fish as a tool in the fishing
%U http://www.hindawi.com/journals/ijocean/2013/678621/