@inproceedings{fdi:010078281,
  title = {{C}omparative analysis of {D}iel {V}ertical migration between three {A}tlantic {A}frican large marine ecosystems [r{\'e}sum{\'e} de poster]},
  author = {{T}iedemann, {M}. and {B}rehmer, {P}atrice and {M}ouget, {A}nne and {E}l {A}youbi, {S}. and {B}ehagle, {N}olwenn and {P}errot, {Y}annick and {C}harouki, {N}. and {M}igayrou, {C}. and {U}anivi, {U}. and {J}eyid, {M}.{A}. and {M}bye, {E}.{M}. and {R}odriguez, {E}. and {S}arr{\'e}, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{D}iel vertical migration ({DVM}) of micronekton is a behavioural mechanism driven by a trade-off between predator avoidance and access to prey. {T}his trade-off is controlled by environmental forcing that can lead to changes of {DVM} pattern under changing environmental conditions. {T}ime series of hydro acoustic surveys between 1995 – 2015 of three large {A}tlantic ecosystems ({C}anary {C}urrent - {CCLME}, {G}uinea {C}urrent - {GCLME}, and {B}enguela {C}urrent - {BCLME}) were analysed to calculate {DVM} patterns based on volume backscattering strength ({S}v). {DVM} related descriptors (n=15) were calculated for areas according to bathymetric definitions (shelf = 10 – 150 m bottom depth, slope = 150 – 500 m bottom depth, and plain > 500 m bottom depth). {T}ypical {DVM} {I} pattern, with micronekton descending during daytime and ascending during night-time, were observed on the slope and plain in all three ecosystems, but not on the shelf with only negative day-night values in the {CCLME} and {BCLME}. {L}ower daytime {S}v values during the day compared to night-time suggest either less dense patches of micronekton leading to negative day-night differences in the {CCLME} and {GCLME} or insufficient measurements of certain depth strata (e.g., 0 – 10 m surface). {O}nly a few significant and different {DVM} descriptors suggest a change in the {CCLME} and the {GCLME} in the last 20 years. {A}ll other insignificant descriptors assume natural variability in large {A}tlantic ecosystems. {O}ur results provide insight into inter-annual variability in micronekton {DVM} patterns.},
  keywords = {{AFRIQUE} {DE} {L}'{OUEST} ; {ATLANTIQUE}},
  numero = {},
  pages = {153},
  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:010078281},
}