@inproceedings{fdi:31194,
  title = {{S}hort-term variability of {S}ardinella aurita aggregation and consequencies on acoustic survey results},
  author = {{F}r{\'e}on, {P}ierre and {S}oria, {M}arc and {G}erlotto, {F}ran{\c{c}}ois},
  editor = {},
  language = {{ENG}},
  abstract = {{A} single fish assemblage of #{S}ardinella aurita$ was tracked over 24 hours by a research vessel equipped with acoustic devices in order to study the short-term variability of its distribution pattern in the {G}ulf of {C}ariaco ({V}enezuela). {O}bviously the studied assemblage did not follow the usually observed aggregation pattern, considered to depend mainly on the light intensity. {N}or did the mean depth of the biomass correspond exactly to the usual diurnal cycle pattern. {D}ense schools were observed during the first night in absence of moonlight; they dove from 15 to 35 m depth in the morning, but came back close to the surface (19 m) early in the afternoon and remained dense during the following night. {F}uthermore the fish assemblage apparently presented a contagious structure most of the time, with an increasing density from the periphery (dispersed fish and/or small schools) to the center (large schools or aggregation). {P}ractical conclusions are drawn from these observations, specifically on the survey design (oversampling strategy on densest area) and on the data analysis (inaccuracy of the night/day data split in some cases). ({R}{\'e}sum{\'e} d'auteur)},
  keywords = {{PROSPECTION} {ACOUSTIQUE} ; {POISSON} {MARIN} ; {ESPECE} {PELAGIQUE} ; {ETHOLOGIE} ; {STRUCTURE} {DE} {POPULATION} ; {VARIATION} {JOURNALIERE} ; {BANC} ; {VENEZUELA} ; {CARIACO} {GOLFE}},
  numero = {26},
  pages = {16  multigr.},
  booktitle = {{C}ollected reprints of the main contributed papers of {EICHOANT} program ({E}valuation of {B}ehaviour {I}nfluence on {F}ishery {B}iology and {A}coustic {O}bservations in {T}ropical {O}pen {S}ea) presented during congresses from 1/1/87 to 4/30/90 = {C}ompilation des principales communications du programme {EICHOANT} ({E}valuation de l'{I}mpact du {C}omportement en {H}alieutique et sur les {O}bservations {A}coustiques en {M}ilieu {N}aturel {T}ropical) pr{\'e}sent{\'e}es {\`a} des congr{\`e}s entre le 1/1/87 et le 30/4/90},
  year = {1990},
  URL = {https://www.documentation.ird.fr/hor/fdi:31194},
}