@article{fdi:010076050,
  title = {{M}ultidecadal changes in marine subsurface oxygenation off central {P}eru during the last ca. 170 years},
  author = {{C}ardich, {J}. and {S}ifeddine, {A}bdelfettah and {S}alvatteci, {R}. and {R}omero, {D}. and {B}riceno-{Z}uluaga, {F}. and {G}raco, {M}. and {A}nculle, {T}. and {A}lmeida, {C}. and {G}utierrez, {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{S}ubsurface water masses with permanent oxygen deficiency (oxygen minimum zones, {OMZ}) are typically associated with upwelling regions and exhibit a high sensitivity to climate variability. {O}ver the last decade, several studies have reported a global ocean deoxygenation trend since 1960 and a consequent {OMZ} expansion. {H}owever, some proxy records suggest an oxygenation trend for the {OMZ} over the margins of the {T}ropical {N}orth {E}ast {P}acific since ca. 1850. {A}t the {T}ropical {S}outh {E}ast {P}acific, the upper {P}eruvian margin is permanently impinged by a shallow and intense {OMZ}. {I}n this study, we aim to (1) reconstruct the (multi)decadal oxygenation variability off central {P}eru, and (2) to identify the influence of both largescale and local factors and the potential underlying mechanisms driving subsurface oxygenation in the {E}astern {P}acific. {W}e combined a multiproxy approach in multiple paleoceanographic records for the last similar to 170 years with instrumental records of subsurface oxygen concentrations since 1960. {W}e analyzed benthic foraminiferal assemblages, redox-sensitive metals ({M}o, {R}e, {U}), delta {N}-15 and contents of total organic carbon and biogenic silica in multiple sediment cores collected in the upper margin off {C}allao (180 m) and {P}isco (similar to 300 m). {A}n {OMZ} weakening over the {P}eruvian central margin can be inferred from 1865 to 2004. {T}he records can be divided in three major periods, based on responses of local productivity and subsurface ventilation: (i) the mid to late 19th century, with enhanced siliceous productivity, a strong oxygen-deficient and reducing sedimentary conditions; (ii) the late 19th century to mid-twentieth century, with less oxygen-deficient and reducing sedimentary conditions, superimposed to a slight decadal-scale variability; and (iii) the late 20th century until the early 2000's, with a slight oxygenation trend. {W}e attribute the centennial-scale oxygenation trend in the {T}ropical {E}ast {P}acific to ventilation processes by undercurrents that decreased subsurface oxygenation even when during the same period an overall increase in export production was inferred off {P}eru. {U}nlike other upwelling areas in the {T}ropical {E}ast {P}acific, subsurface oxygenation off {P}eru does not show a decrease in the last decades, instead a subtle oxygenation trend was observed close to the core of the {OMZ} at 200 m depth.},
  keywords = {deoxygenation ; {OMZ} ; redox metals ; benthic foraminifers ; {P}eru ; {PEROU} ; {PACIFIQUE} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{F}rontiers in {M}arine {S}cience},
  volume = {6},
  numero = {},
  pages = {270 [16 ]},
  year = {2019},
  DOI = {10.3389/fmars.2019.00270},
  URL = {https://www.documentation.ird.fr/hor/fdi:010076050},
}