@inproceedings{fdi:010078272,
  title = {{T}he effect of oceanographic factors on micronektonic acoustic density in the three {A}frican {A}tlantic large marine ecosystems [r{\'e}sum{\'e} du poster]},
  author = {{B}rehmer, {P}atrice and {D}emarcq, {H}erv{\'e} and {M}ouget, {A}nne and {M}igayrou, {C}. and {C}harouki, {N}. and {K}on{\'e}, {V}. and {U}anivi, {U}. and {S}arr{\'e}, {A}. and {J}eyid, {M}.{A}. and {K}ouassi, {A}.{M}. and {P}errot, {Y}annick and {B}ehagle, {N}olwenn and {K}rakstad, {J}.{O}. and {D}iallo, {I}. and {D}iogoul, {N}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he interest of modelling the effect of oceanographic factors on micronektonic acoustic densities and its variability is relevant in the context of climate change to better understand the environmental processes controlling ecosystem productivity. {U}ltimately for the stakeholders, we plan to forecast changes induced by climate change effects and study inter annual variability. {S}atellite data have been processed using the same time steps as the time series of fisheries acoustic surveys carried out by the {R}/{V} {D}r. {F}ridtjof {N}ansen along the {A}tlantic {A}frican coasts, overlapping three {L}arge {M}arine {E}cosystems. {T}he observed split at {C}ape {B}lanc (21°{N}) separates the coastal upwelling into a strong and stable dynamic upwelling, and a highly seasonal one. {B}ecause of the highly non-linear nature of the relationships the {BRT} modelling accounts for a considerably higher part of the environmental variability, compared to classic multivariate approaches. {E}nvironmental data are extracted from daily series of {AVHRR} ({SST}), {MODIS} ({SST} and {C}hl-a) and others at spatial resolution between 4 and 25 km. {B}oosted {R}egression {T}ree classification is well suited to show the importance of the large scale environmental variability, despite a limited set of variables. {I}t is interesting to note that the inter-annual variability is not significant in the model, showing that the underlying environmental forcing is associated with relatively stable processes. {T}he structural variables, i.e., bathymetry and distance to the coast, consistently explain a large part of the variability. {SST} has a minor influence in the north (consistently cold and windy) and a pronounced effect in the south where seasonality is high and variable. {E}specially in {S}enegal and {G}uinea, the detrimental effects of the coastal upwelling (mostly offshore drifts due to strong winds) are strongly attenuated by the wider continental shelf which favour retention processes. {T}he next step will be to couple our results with climate projections to forecast major changes in {A}frican coastal systems as the micronektonic compartment is essential at mid-trophic level in all marine ecosystems. {C}onsidering the oceanographic factors relative influence, and under the assumption of similar warming in the three {A}tlantic {A}frican {LME}s, a stronger ecosystem perturbation is expected in {BBCLME}, then in the {CCLME} and particularly when comparing the southern part of the {CCLME} vs {N}orth part. {I}n all {LME} i.e. including {GCLME}, the oceanographic factors relative influence get a significant role confirming the important changes expected due to climate change on the ecosystems and thus in the fisheries.},
  keywords = {{AFRIQUE} {DE} {L}'{OUEST} ; {SENEGAL} ; {GUINEE} ; {ATLANTIQUE}},
  numero = {},
  pages = {137--138},
  booktitle = {{I}nternational conference {ICAWA} 2017 and 2018 : extended book of abstract : the {AWA} project : ecosystem approach to the management of fisheries and the marine environment in {W}est {A}frican waters},
  year = {2019},
  ISBN = {978-9553602-0-06},
  URL = {https://www.documentation.ird.fr/hor/fdi:010078272},
}