Hindawi Publishing Corporation International Journal of Oceanography Volume 2013, Article ID 678621, 9 pages http://dx.doi.org/10.1155/2013/678621 Review Article The Development of SONAR as a Tool in Marine Biological Research in the Twentieth Century John A. Fornshell1 and Alessandra Tesei2 1 National Museum of Natural History, Department of Invertebrate Zoology, Smithsonian Institution, Washington, DC, USA 2 AGUAtech, Via delle Pianazze 74, 19136 La Spezia, Italy Correspondence should be addressed to John A. Fornshell;
[email protected] Received 3 June 2013; Revised 16 September 2013; Accepted 25 September 2013 Academic Editor: Emilio Fernandez´ Copyright © 2013 J. A. Fornshell and A. Tesei. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 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.