%0 Book Section
%9 OS CH : Chapitres d'ouvrages scientifiques
%A Marchal, Emile
%A Josse, Erwan
%A Lebourges, Anne
%T Predators and preys : an acoustic approach
%B Proceedings of acoustics seminar AKUSTIKAN 2
%C Luxembourg (LUX) ; Jakarta (IDN) ; Paris
%D 1997
%E Petit, Didier
%E Cotel, Pascal
%E Nugroho, D.
%L fdi:010017258
%G ENG
%I Union Européenne ; CRIFI ; ORSTOM
%@ 979-8186-64-8
%K POISSON MARIN ; THON ; PREDATEUR ; RELATION PREDATEUR PROIE ; ETHOLOGIE ; ABONDANCE ; EVALUATION ; PROSPECTION ACOUSTIQUE
%P 253-264
%U https://www.documentation.ird.fr/hor/fdi:010017258
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_7/carton01/010017258.pdf
%W Horizon (IRD)
%X Predators seek congregated rather than scattered prey, and school themselves most of the time. In order to study the relationship between predators and preys, one needs to identify them. Classical methods of investigation, such as the use of different kinds of net (plankton, midwater trawl) with a regular sampling grid, often fail to succeed in catching them, due to their very heterogeneous distribution. In contrast, acoustics allows us to "see" and to study them, thanks to the very good transmission of sound in the water. A good example of the way acoustics could be used to study predator-prey relationships is provided by a tuna fishery in the Equatorial Atlantic which exploits a seasonal tuna concentration. It was assumed that tuna find here abundant food, supported by the very high percentage of a mesopelagic fish, #Vinciguerria nimbaria$, found in their stomach contents. However, this fish is known as a dial migrator, diving to deep waters during the daytime, where tuna could not catch them since they are view-feeders. Acoustic detection has proven that, in this case, this small fish could stay in the surface layers, aggregating in small schools at the thermocline level. In addition, acoustic tagging has shown that tuna were staying most of the time at this particular level. Finally, acoustic estimation of the packing density and the volume of these schools allows us to assume their actual role in the daily feeding of tuna. (Résumé d'auteur)
%B AKUSTIKAN : Seminar
%8 1996/05/27-29
%$ 036MILMAR02