Climatic variavility and fishery in the Humboldt system. A look to the past from the sedimentary record

Thursday March 21th, Jorge Valdés, Senior Researcher from the University of Antofagasta (Chile), presented at the “Café con Sal” conference cycle the lecture “Climatic variavility and fishery in the Humboldt system: A look to the past from the sedimentary record“.

Marine oxygen-deficient environments with high sedimentation rates and high primary productivity can provide relevant information regarding variations of ocean-climatic conditions in the past. The Humboldt Current ecosystem, which now hosts huge populations of pelagic fishes (mainly anchovy and sardine), preserve in the bottom sediment fish debris that may be a useful indicator of past environmental change.

One of the coastal zones with a well-preserved sedimentary record of past ocean-climatic fluctuations is Mejillones Bay (23ºS, northern Chile). In this bay, different studies shows that bottom sediments preserve a record of pelagic fish fluctuations during the past millennia. These fluctuations, principally of sardine and anchovy evidence the impact of industrial catches, and validate the use of debris fish as a proxy of local fish biomass.

During his conference, Jorge Valdés presented the cycles of increase and decrease of anchovy and sardine populations in the past milennia showing their agreement with changes in the wind regime, sea-surface temperature, primary productivity, oxygen deficiency and different oceanographic regime as the “ENSO-like” interdecadal variability.

The conference took place at the conference room of the ECIMAT at 11:00h (CES) and was live streamed on http://tv.uvigo.es/es/directo/1.html being permanently available on CIM and UVigoTV websites.

Vídeos