Fréon Pierre, Gerlotto François, Soria Marc. (1992). Changes in school structure according to external stimuli : description and influence on acoustic assessment. Fisheries Research, 15, p. 45-66. ISSN 0165-7836.
Titre du document
Changes in school structure according to external stimuli : description and influence on acoustic assessment
Année de publication
1992
Type de document
Article
Auteurs
Fréon Pierre, Gerlotto François, Soria Marc
Source
Fisheries Research, 1992,
15, p. 45-66 ISSN 0165-7836
The study of the internal school structure and behaviour of pelagic fish provides interesting information in relation to acoustic surveys, especially when comparing the undisturbed structure with the structure observed beneath a vessel passing over a school. The methodological approach involves in situ observations and combines acoustic and visual (aerial and underwater) techniques. The internal school structure is heterogeneous, including vacuoles, and this structure changes when the school is overpassed by a vessel during the day. In this case compression of the upper layer of the school is observed. The influence of this school structure on the variability of the density estimation has been studied. For the subsurface schools, the usual rate of sampling may be too low for some heterogenous schools. Other consequences of the school structure on acoustics are discussed. (Résumé d'auteur)
