@article{fdi:010070025,
  title = {{L}arval fish assemblages across an upwelling front : indication for active and passive retention},
  author = {{T}iedemann, {M}. and {B}rehmer, {P}atrice},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n upwelling areas, enrichment, concentration and retention are physical processes that have major consequences for larval fish survival. {W}hile these processes generally increase larval survival, strong upwelling can also increase mortality due to an offshore transport of larvae towards unfavorable habitats. {I}n 2013 a survey was conducted along the {S}enegalese coast to investigate the upwelling effect with regard to larval fish assemblages and possible larval fish retention. {A}ccording to water column characteristics two distinct habitats during an upwelling event were discriminated, i.e. the inshore upwelled water and the transition area over the deepest part of the {S}enegalese shelf. {A}long the two areas 42,162 fish larvae were collected representing 133 species within 40 families. {H}ighest larval fish abundances were observed in the inshore area and decreasing abundances towards the transition, indicating that certain fish species make use of the retentive function of the inner shelf area as spawning grounds. {T}wo larval fish assemblages overlap both habitats, which are sharply delimited by a strong upwelling front. {O}ne assemblage inhabited the inshore/upwelling area characterized by majorly neritic and pelagic species ({S}paridae spp., {S}ardinella aurita), that seem to take the advantage of a passive retention on the shelf. {T}he second assemblage consisted of a mix of pelagic and mesopelagic species ({E}ngraulis encrasicolus, {C}arangidae spp. and {M}yctophidae spp.). {S}ome species of the second assemblage, e.g. horse mackerels ({T}rachurus trachurus and {T}rachurus trecae), large finned-lantern fish ({H}ygophum macrochir) and foureyed sole ({M}icrochints ocellatus), revealed larval peak occurrences at intermediate and deep water layers, where the near-ground upwelling layer is able to transport larvae back to the shelf. {T}his indicates active larval retention for species that are dominant in the transition area. {D}iel vertical migration patterns of {S}. aurita, {E}. encrasicolus and {M}. ocellatus revealed that a larval fish species may adapt its behavior to the local environment and do not necessarily follow a diurnal cycle. {F}ield observations are essential to be integrated in larval drift models, since the vertical and horizontal larval distribution will have major consequences for survival. {C}omprehending larval survival mechanisms is necessary for the ultimate goal to understand and predict recruitment.},
  keywords = {{F}ish larvae ; {D}iel vertical migration ; {U}pwelling front ; {N}orthwest {A}frica ; {C}anary current large marine ecosystem ; {O}cean triad ; {SENEGAL} ; {ATLANTIQUE}},
  booktitle = {},
  journal = {{E}stuarine {C}oastal and {S}helf {S}cience},
  volume = {187},
  numero = {},
  pages = {118--133},
  ISSN = {0272-7714},
  year = {2017},
  DOI = {10.1016/j.ecss.2016.12.015},
  URL = {https://www.documentation.ird.fr/hor/fdi:010070025},
}