@article{fdi:010077724,
  title = {{S}patio-temporal trends in zooplankton biomass in the northern {H}umboldt current system off {P}eru from 1961-2012},
  author = {{A}rones, {K}. and {G}rados, {D}. and {A}yon, {P}. and {B}ertrand, {A}rnaud},
  editor = {},
  language = {{ENG}},
  abstract = {{A}nchovy ({E}ngraulis ringens) is the most important exploited fish species in the {N}orthern {H}umboldt {C}urrent {S}ystem ({NHCS}) off {P}eru. {T}his species, as well as most other pelagic resources, mainly forage on zooplankton. {T}he {NHCS} is bottom-up controlled at a variety of scales. {T}herefore, fish biomass is driven by the abundance of their prey. {I}n this context, we studied the spatiotemporal patterns of zooplankton biomass in the {NHCS} from 1961-2012. {D}ata were collected with {H}ensen net all along the {P}eruvian coast. {T}o transform zooplankton biovolume into biomass we used a regression that was calibrated from 145 zooplankton samples collected during four surveys and, for which, precise information was available on both biovolume and wet weight. {T}he regression model was then applied on a time-series encompassing 158 cruises performed by the {P}eruvian {I}nstitute of the {S}ea ({IMARPE}) between 1961 and 2012. {W}e observed a clear multidecadal pattern and two regime shifts, in 1973 and 1992. {M}aximum biomass occurred between 1961 and 1973 (61.5 g m(-2)). {T}he lowest biomass (17.8 g m(-2)) occurred between 1974 and 1992. {F}inally, the biomass increased after 1993 (26.6 g m(-2)) but without reaching the levels observed before 1973. {A} seasonal pattern was observed with significantly more biomass in spring than in other seasons. {S}patially, zooplankton biomass was higher offshore and in northern and southern {P}eru. {I}nterestingly, the zooplankton sampling was performed using classic zooplankton net that are well fitted to mesozooplankton and are known to underestimate the macrozooplankton; however, the spatiotemporal patterns we observed are consistent with those of macrozooplankton, in particular euphausiids. {T}his suggests that in the {NHCS}, when and where macrozooplankton dominates it also dominates the biomass obtained using classic zooplankton net samples. {F}inally, until now, in the {NHCS} only time-series on zooplankton biovolume were available. {T}he biomass data we provide are more directly usable in trophic or end-to-end models.},
  keywords = {{S}econdary production ; {M}esozooplankton ; {M}acrozooplankton ; {R}egime-shift ; {S}patiotemporal distribution ; {D}ecadal trends ; {PEROU} ; {PACIFIQUE}},
  booktitle = {},
  journal = {{D}eep-{S}ea {R}esearch {P}art {II} : {T}opical {S}tudies in {O}ceanography},
  volume = {169},
  numero = {{N}o {S}p{\'e}cial},
  pages = {art. 104656 [6 p.]},
  ISSN = {0967-0645},
  year = {2019},
  DOI = {10.1016/j.dsr2.2019.104656},
  URL = {https://www.documentation.ird.fr/hor/fdi:010077724},
}