Mouget A. auteur aut IRD Acou A. auteur aut IRD David V. auteur aut IRD Feunten E. auteur aut IRD Thiriet P. auteur aut IRD Perrot Yannick auteur aut IRD Sarre A. auteur aut IRD Diogoul N. auteur aut IRD Vehlo F. auteur aut IRD Koné V. auteur aut IRD Brehmer Patrice auteur aut IRD text conferencePaper eng text/pdf reformatted digital access Fisheries acoustic tools, widely used in open ocean contexts, have become more common in shallow waters, but there is still a lack of information in ultra-coastal area (<15 m depth). Additionally, environmental parameters beyond bathymetry, such as seafloor terrain, likely play significant roles for biocenose aggregation, distribution and diversity in shallow waters. Pelagic fish shoals, aggregations of fish, are sensitive to environmental factors and can serve as proxies to monitor ecosystems. Various physical parameters, such as time of day and distance to coast, influence fish distribution. This study aims to investigate the impact of topographic variables on pelagic shoals across off-shore to coastal areas (5-500 m depth). Two datasets from French Brittany and West African coasts were analyzed to highlight global patterns and local specificities. The analysis focuses on coastal and shallow waters, aiming to identify common patterns across systems while recognizing potential differences, particularly in upwelling systems. This study highlight the importance of ultra-coastal area, with a high relative biomass (Sv). The analyze of common patterns revealed the importance of bathymetry in all studied systems. Some other topographic variables have been discovered as important in many systems. However, each system presents its own specificities, with similarity between systems with or without upwelling. specialized FRANCE BRETAGNE AFRIQUE DE L'OUEST ATLANTIQUE 040AQUAC 082ECOSYS ICES. Working Group of Fisheries Acoustics, Science and Technology (WGFAST), Plouzané (FRA), 2024/04/09-2024/04/12 32 Copenhague CIEM 2024 https://www.documentation.ird.fr/hor/fdi:010091527 [F B010091527] https://www.documentation.ird.fr/hor/fdi:010091527 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2024-08/010091527.pdf IRD - Base Horizon / Pleins textes 2024-07-29 2024-08-07 fdi:010091527 fre