Characterization of Oxygen Minimum Zone (OMZ) in front of Peruvian coast between 3°N and 14°S, 1999 - 2009

Abstract

Data were analyzed for dissolved oxygen, in front of the coast of Peru, to understand the variations of the OMZ, characterized by: a) the thickness of the area bounded by the oxygen isolines of 0.5 mL.L-1; and b) the depth of its upper limit in the marine coastal strip. We show the results of evaluations in the water column in the Bay of Callao during the period 1999 - 2009, and also in January-February 2009 in a study of the OMZ during Meteor Cruise 77-4 0901-02: Interaction in the Tropical Ocean, Biogeochemistry and Climate. In the marine coastal zone of Callao (12°S) hypoxia is accentuated, the OMZ is constrained by the platform and its upper surface is located more than 2.5 m deep. From the information obtained in January - February 2009 (Cruise 0901-02) examined the spatial variability of the OMZ, where a thickness of ~ 637.8 m was found in Punta Falsa section (6°S). We analyzed the dynamics of the OMZ and its upper limit, due to the great interest taken by the possible increase of its thickness in the context of climate change, with major impact on fisheries resources.