@article{fdi:010049096,
  title = {{M}echanisms affecting recovery in an upwelling food web : the case of the southern {H}umboldt},
  author = {{N}eira, {S}. and {M}oloney, {C}. {L}. and {C}ury, {P}hilippe and {M}ullon, {C}hristian and {C}hristensen, {V}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}lthough bottom-up forcing and overfishing are known to induce shifts in ecosystem states, system changes and their reversibility under each factor are still poorly understood. {I}n this paper, dynamic food web simulations are conducted to evaluate when and why ecological thresholds may be exceeded, and whether bottom-up forcing or fishing is more likely to induce irreversible ecosystem states. {S}imulations are conducted using a calibrated food web model of the upwelling system off central {C}hile (33-39 degrees {S}) and the {E}copath with {E}cosim software version 5.1. {T}he effects of fishing scenarios are explored by changing fishing mortality according to trophic level. {T}he effects of bottom-up forcing scenarios are explored by changing phytoplankton biomass, as a function of sea temperature, at {E}l {N}ino {S}outhern {O}scillation ({ENSO}) and decadal scales. {S}imulations are carried out for 150 years and impacts, system recovery and regime shifts from each scenario are evaluated using trophodynamic indicators and limit reference points for biomass of functional groups as proxies of food web state and ecological thresholds, respectively. {P}roportionally distributed fishing along trophic levels is the least harmful fishing scenario, resulting in biomass limit reference points rarely being exceeded and high system recovery. {C}oncentrating fishing at higher and lower trophic levels more likely causes reference points to be exceeded and induces ecosystem changes with low-to-medium recovery potential. {N}o limit reference points are exceeded (or regime shift induced) under {ENSO}-scale bottom-up forcing. {D}ecadal scale bottom-up forcing has different effects on the system depending on the sequence in which the high and low phytoplankton biomass periods are simulated. {A} shift from low phytoplankton biomass towards high phytoplankton biomass does not result in biomass limit reference points being exceeded, whereas the opposite sequence results in a large number of limit reference points being exceeded with medium recovery. {T}he interplay between fishing and decadal scale bottom-up forcing indicates that bottom-up forcing can dampen the effects of fishing, whereas fishing increases the number of limit reference points exceeded and decreases the recovery observed under decadal scale bottom-up forcing. {R}esults suggest that fishing (especially unsustainable strategies) is more likely to cause ecological thresholds to be exceeded and to induce regime shifts of low recovery than decadal scale bottom-up forcing. {W}e consider these results of relevance for the management of fisheries in their ecosystem context.},
  keywords = {},
  booktitle = {},
  journal = {{P}rogress in {O}ceanography},
  volume = {83},
  numero = {1-4},
  pages = {404--416},
  ISSN = {0079-6611},
  year = {2009},
  DOI = {10.1016/j.pocean.2009.07.007},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049096},
}