@article{fdi:010094808,
  title = {{S}patial distributions of acoustic scattering groups during the warm-to-cold transition period in the {S}enegal coastal ecosystem and their relationships with environmental variables},
  author = {{D}avid, {V}iviane and {H}abasque, {J}{\'e}r{\'e}mie and {R}oudaut, {G}ildas and {M}arie, {L}. and {T}hibault, {D}. and {L}ebourges {D}haussy, {A}nne and {C}apet, {X}. and {M}achu, {E}ric},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he coastal area of north-west ({NW}) {A}frica is a highly productive ecosystem due to the presence of a strong upwelling. {T}his ecosystem supports large populations of small pelagic fish, such as sardinellas, which have significant socio-economic value for local populations. {I}n this study, we analyzed the acoustic data collected during a one-month survey along the {S}enegalese coast at the beginning of the upwelling season. {H}ierarchical clusterings were performed to classify the acoustic data from the epipelagic zone (down to 120 m-depth) separately for daytime and nighttime. {T}he analysis identified five echo-groups during the day and six at night. {T}he resulting echo-groups were then compared to stratified midwater trawl samplings to support hypotheses about the organisms responsible for the echoes. {A}dditionally, a remotely operated towed vehicle (called {S}can-fish) was used to monitor environmental variables down to 100 m depth. {T}wo machine learning models were applied to link the classified echo-groups to the environmental data for both day and night. {E}ach daytime echo group had a corresponding nighttime echo group, with also similar environmental preferences. {F}ish schools were mainly found in shallow coastal waters while dense sound-scattering layers detected at 38 k{H}z, likely composed of small fish or fish larvae, were observed in the temperature range of 17 degrees-21 degrees {C} for both day and night. {T}he other echo-groups were composed of fluid-like zooplankton or gas-bearing zooplankton. {T}he sixth night echo-group corresponded to migrant organisms and was predominant at night. {O}verall, the analyses of the abiotic habitats for each echo-group allow us to better understand the organism distributions during the beginning of the {NW} {A}frica upwelling season.},
  keywords = {{A}ctive acoustics ; {M}icronekton ; {S}enegal ; {U}pwelling ; {SENEGAL} ; {ATLANTIQUE}},
  booktitle = {},
  journal = {{J}ournal of {M}arine {S}ystems},
  volume = {251},
  numero = {},
  pages = {104113 [14 p.]},
  ISSN = {0924-7963},
  year = {2025},
  DOI = {10.1016/j.jmarsys.2025.104113},
  URL = {https://www.documentation.ird.fr/hor/fdi:010094808},
}