@article{fdi:010065771,
  title = {{D}iet diversity of jack and chub mackerels and ecosystem changes in the northern {H}umboldt {C}urrent system : a long-term study},
  author = {{A}legre, {A}. and {B}ertrand, {A}rnaud and {E}spino, {M}. and {E}spinoza, {P}. and {D}ioses, {T}. and Ñiquen, {M}. and {N}avarro, {I}. and {S}imier, {M}onique and {M}{\'e}nard, {F}r{\'e}d{\'e}ric},
  editor = {},
  language = {{ENG}},
  abstract = {{J}ack mackerel {T}rachurus murphyi ({JM}) and chub mackerel {S}comber japonicus ({CM}) are medium size pelagic fish predators and highly exploited resources. {H}ere we investigated the spatiotemporal patterns of {JM} and {CM} diet composition using a large dataset of stomach samples collected from 1973 to 2013 along the {P}eruvian coast. {I}n total 47,535 stomachs (18,377 {CM} and 29,158 {JM}) were analysed, of which 23,570 (12,476 {CM} and 11,094 {JM}) were non-empty. {R}esults show that both species are opportunistic and present a trophic overlap. {H}owever, despite their smaller maximal size, {CM} consumed more fish than {JM}. {B}oth diets presented high spatiotemporal variability. {S}patially, the shelf break appears as a strong biogeographical barrier affecting prey species distribution and thus {CM} and {JM} diet. {O}pportunistic foragers are often considered as actual indicators of ecosystem changes; we show here that diet composition of {CM} and {JM} reveal ecosystem changes but is not always a good indicator of changes in prey biomass as prey accessibility and energy content can also play an important role. {I}n addition we found that {E}l {N}iño events have a surprisingly weak effect on stomach fullness and diet. {F}inally our results show that the classic paradigm of positive correlation between diversity and temperature is unlikely to occur in the {H}umboldt {C}urrent system where productivity seems to be the main driver. {W}e show how energy content of forage species and the strength of the oxygen minimum zone most likely play an important role prey diversity and accessibility, and thus in fish foraging behaviour.},
  keywords = {{PEROU} ; {PACIFIQUE}},
  booktitle = {},
  journal = {{P}rogress in {O}ceanography},
  volume = {137},
  numero = {{P}art {A}},
  pages = {299--313},
  ISSN = {0079-6611},
  year = {2015},
  DOI = {10.1016/j.pocean.2015.07.010},
  URL = {https://www.documentation.ird.fr/hor/fdi:010065771},
}