Publications des scientifiques de l'IRD

Brochier Timothée, Echevin Vincent, Tam J., Chaigneau Alexis, Goubanova Katerina, Bertrand Arnaud. (2013). Climate change scenarios experiments predict a future reduction in small pelagic fish recruitment in the Humboldt Current system. Global Change Biology, 19 (6), p. 1841-1853. ISSN 1354-1013.

Titre du document
Climate change scenarios experiments predict a future reduction in small pelagic fish recruitment in the Humboldt Current system
Année de publication
2013
Type de document
Article référencé dans le Web of Science WOS:000318353300016
Auteurs
Brochier Timothée, Echevin Vincent, Tam J., Chaigneau Alexis, Goubanova Katerina, Bertrand Arnaud
Source
Global Change Biology, 2013, 19 (6), p. 1841-1853 ISSN 1354-1013
The Humboldt Current System (HCS) sustains the worlds largest small pelagic fishery. While a cooling of this system has been observed during recent decades, there is debate about the potential impacts of rising atmospheric CO2 concentrations on upwelling dynamics and productivity. Recent studies suggest that under increased atmospheric CO2 scenarios the oceanic stratification may strongly increase and upwelling-favorable winds may remain nearly constant off Peru and increase off Chile. Here we investigate the impact of such climatic conditions on egg and larval dispersal phases, a key stage of small pelagic fish reproduction. We used larval retention rate in a predefined nursery area to provide a proxy for the recruitment level. Numerical experiments are based on hydrodynamics downscaled to the HCS from global simulations forced by pre-industrial (PI), 2xCO2 and 4xCO2 scenarios. A biogeochemical model is applied to the PI and 4xCO2 scenarios to define a time-variable nursery area where larval survival is optimum. We test two distinct values of the oxycline depth that limits larval vertical distribution: One corresponding to the present-day situation and the other corresponding to a shallower oxycline potentially produced by climate change. It appeared that larval retention over the continental shelf increases with enhanced stratification due to regional warming. However, this increase in retention is largely compensated for by a decrease of the nursery area and the shoaling of the oxycline. The underlying dynamics are explained by a combination of stratification effects and mesoscale activity changes. Our results therefore show that future climate change may significantly reduce fish capacity in the HCS with strong ecological, economic and social consequences.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Sciences du milieu [021] ; Limnologie biologique / Océanographie biologique [034]
Description Géographique
OCEAN PACIFIQUE ; PEROU ; CHILI ; PACIFIQUE EST ; PACIFIQUE SUD
Localisation
Fonds IRD [F B010060333]
Identifiant IRD
fdi:010060333
Contact