@article{fdi:010046034,
  title = {{A} new hypothesis concerning the nature of small pelagic fish clusters {A}n individual-based modelling study of {S}ardinella aurita dynamics off {W}est {A}frica},
  author = {{L}e {F}ur, {J}ean and {S}imon, {P}.},
  editor = {},
  language = {{ENG}},
  abstract = {{C}oastal populations of small pelagic fish display nested aggregation levels. {A}bove the level of the school structure, clusters are observed the nature of which has not been definitively determined. {W}e hypothesized that these clusters corresponded to a materialisation of the microcohorts originating from successive spawnings of fish populations in their vital domain. {A} candidate individual-based model was developed to investigate this hypothesis. {T}his model is based on pattern-oriented modelling of a concrete documented case: the dynamics of the round sardinella ({S}ardinella aunita) population living off the {W}est {A}frican coasts and subject to environmental fluctuations caused by seasonal upwelling. {T}he simulated agents were round sardinella microcohorts situated and moving in a discretised physical environment. {T}he combined effects of environmental forcing (temperature, wind, retention) and inner biological dynamics (reproduction, growth and mortality, competition) condition the dynamics of this population. {T}he modelled behaviour generated realistic dynamic patterns (population distribution, spawning zones, periods and plasticity, biomass fluctuations), which were obtained simultaneously and successfully compared with observations. {T}he steady-state number of microcohorts obtained after simulation convergence was similar to the number of clusters observed in situ in this area for this population. {T}he realism and diversity of the patterns simultaneously simulated suggested the cluster-microcohort equivalence hypothesis as a candidate framework accounting for the origin of the clusters observed in situ. {W}ithin this preliminary exploration, we discuss the consistency of the hypothesis and the accuracy of the model. {I}f the correspondence between clusters and microcohorts proves to be real, it may be transient and progressively modified by other environmental factors. {I}f stable over time, as simulated in the model, the number of observed clusters should be related to the number of spawning events in the species' lifetime.},
  keywords = {{I}ndividual-based model ; {O}bserved patterns ; {U}pwelling ; {S}mall pelagic fishes ; {S}ardinella aurita ; {W}est {A}frica ; {M}icrocohort ; {C}luster ; {A}ggregation},
  booktitle = {},
  journal = {{E}cological {M}odelling},
  volume = {220},
  numero = {9-10},
  pages = {1291--1304},
  ISSN = {0304-3800},
  year = {2009},
  DOI = {10.1016/j.ecolmodel.2009.02.012},
  URL = {https://www.documentation.ird.fr/hor/fdi:010046034},
}