@article{fdi:010040645,
  title = {{A}ssemblages of phytoplankton pigments along a shipping line through the {N}orth {A}tlantic and tropical {P}acific},
  author = {{D}andonneau, {Y}ves and {N}iang, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A} set of phytoplankton pigment measurements collected on eight quarterly transects from {F}rance to {N}ew {C}aledonia is analyzed in order to identify the main assemblages of phytoplankton and to relate their occurrence to oceanic conditions. {P}igment concentrations are first divided by the sum [monovinyl chlorophyll a plus divinyl chlorophyll a] to remove the effect of biomass, and second are normalized to give an equal weight to all pigments. {T}he resulting 17 pigments x 799 observations matrix is then classified into 10 clusters using neural methodology. {E}ight out of these 10 clusters have a well marked regional or seasonal character, thus evidencing adapted responses of the phytoplankton communities. {T}he main gradient opposes two clusters with high fucoxanthin and chlorophyll c(1+2) in the {N}orth {A}tlantic in {J}anuary, {A}pril and {J}uly, to three clusters in the {S}outh {P}acific {S}ubtropical {G}yre with high divinyl chlorophyll a, zeaxanthin and phycoerythrin. {O}ne of the clusters in the {S}outh {P}acific {S}ubtropical {G}yre has relatively high zeaxanthin and phycoerythrin contents and dominates in {N}ovember and {F}ebruary (austral summer), while another with relatively high divinyl chlorophylls a and b dominates in {M}ay and {A}ugust (austral winter). {T}he third one in the {S}outh {P}acific is characterized by high carotene concentration and its occurrence peaks in {F}ebruary and {M}ay. {I}n the equatorial current system, one cluster, rich in chlorophylls b and c(1+2), is strictly located in a narrow zone centred at the equator, while another with relatively high violaxanthin concentration is restricted to the high nutrient - low chlorophyll waters in only the southern part of the {S}outh {E}quatorial {C}urrent. {O}ne cluster with relatively high prasinoxanthin content has a spatial distribution spanning the entire {S}outh {E}quatorial {C}urrent. {T}wo clusters have a ubiquitous distribution: one in the equatorial {P}acific, the {C}arribbean {S}ea and the {N}orth {A}tlantic during summer has pigment concentrations close to the average of the entire dataset, and the other in the {S}outh {P}acific {S}ubtropical {G}yre, the {C}arribbean {S}ea and the {N}orth {A}tlantic during autumn clearly has an oligotrophic character. {M}any of the differences between clusters are caused by diagnostic pigments of nano- or picoflagellates. {W}hile the space and time characteristics of the clusters are well marked and might correspond to differences in physical and chemical forcing, knowledge of the ecological requirements of these flagellates is generally lacking to explain how the variability of the environment triggers these clusters.},
  keywords = {photosynthetic pigments ; phytoplankton ; seasonal variability ; equatorial currents ; {N}orth {A}tlantic ; {T}ropical {P}acific},
  booktitle = {},
  journal = {{P}rogress in {O}ceanography},
  volume = {73},
  numero = {2},
  pages = {127--144},
  ISSN = {0079-6611},
  year = {2007},
  DOI = {10.1016/j.pocean.2007.02.003},
  URL = {https://www.documentation.ird.fr/hor/fdi:010040645},
}