Izard L. auteur aut IRD Fonvieille N. auteur aut IRD Nerini D. auteur aut IRD Lebourges Dhaussy Anne auteur aut IRD Roudaut Gildas auteur aut IRD Habasque Jérémie auteur aut IRD Cotté C. auteur aut IRD text conferencePaper eng text/pdf reformatted digital access Information on micronekton (> 1 cm organisms) is globally scarce in the open ocean, and its ver-tical and horizontal distribution in relation to oceanographic structures is poorly known. The complex biodiversity composing micronektonic functional groups lead to even more challenging interpretations of their spatial dynamics. Advanced generations of echosounders emit simulta-neously several acoustic signals (multi-frequency device), allowing a finer view of the micron-ektonic community. While data becomes more abundant and complex, it is crucial to develop statistical tools aiming to objectively extract key components of its variability. In this study, we analyse data recorded onboard the R/V Marion Dufresne from an EK80 echosounder emitting at 18, 38, 70, 120 and 200 kHz. We developed a Multivariate Functional Data Analysis method to identify patterns in micronekton structures across Saint-Paul and New Amsterdam economic exclusive zone, at the boundary between vast oceanic domains. This approach proposes an ob-jective method to analyse the vertical backscatter distribution and quantify temporal and spatial modes of variability in multivariate acoustic data. By filtering the temporal mode, we uncovered a latitudinal acoustic pattern in concordance with hydrological features and biological samples distribution. Such methods could be implemented at a global or local scale and allow 3-D mod-elling of micronekton structuring. specialized OCEAN INDIEN 032 030 ICES. Working Group of Fisheries Acoustics, Science and Technology (WGFAST), Somone (SEN), 2022/04/25-28 4 54 37 Jech M. ed. edt IRD 2022 https://www.documentation.ird.fr/hor/fdi:010088013 [F B010089464] https://www.documentation.ird.fr/hor/fdi:010088013 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2024-03/010088013.pdf IRD - Base Horizon / Pleins textes 2024-02-14 2024-03-01 fdi:010088013 fre